text stringlengths 1 1.11k | source dict |
|---|---|
When you have an equality of sets you almost always have to prove the two inclusions $\subseteq$ and $\supseteq$.
We have $[\frac{1}{n},n]\subseteq (0,+\infty)$ for all $n$ which implies $\bigcup [\frac{1}{n},n]\subseteq (0,+\infty)$.
Now for the other inclusion take $x\in (0,+\infty)$. If $x\geq 1$ there is a $n$ such that $n>x$ and $x\in [\frac{1}{n},n]$. If $x<1$ then $\frac{1}{x}>1$ and you can use the same reasoning. | {
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"url": "https://math.stackexchange.com/questions/1467577/prove-that-the-union-of-1-n-n-0-%E2%88%9E-from-n-1-to-%E2%88%9E"
} |
ros, viso2, transform
Title: Warning about TF to MSG
When I run viso2 mono_odometer I get warnings like
TF to MSG: Quaternion Not Properly Normalized.
I find no translation happens when I move the camera tf are all zeros. Is that because of this warning, which prevent the node to publish tf to odom itself?
Originally posted by Jia on ROS Answers with karma: 1 on 2013-06-17
Post score: 0 | {
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"tags": "ros, viso2, transform",
"url": null
} |
thermodynamics
Title: Why does air get cooler in wind turbines? And in general why it becomes cooler in example the steam that go past a turbine cannot be used indefinitely because first or later it start to condensate into water again. The R.M.S velocity of the gas is given by,
$$v = \sqrt{\frac{3RT}{M}}$$
where R is the universal gas constant, $T$ is the temperature and $M$ is the average molecular mass of the gas.
As you can clearly see, the higher the temperature, the more shall be the velocity of the gas.
When these gas molecules hit the wind turbine, they transfer part of their energy (or momentum) to the turbine which causes the turbine to rotate (the blades of the turbine are bent so that the energy taken from the gas molecules can be maximised). The remaining energy is retained by the gas molecule and obviously lesser kinetic energy implies that its velocity is slower. | {
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"tags": "thermodynamics",
"url": null
} |
\frac{2-x-g(x)}{\sqrt{2 x+\sqrt{2}-1}} \\[1em] &\underset{(13)}{=} \frac{1-2x-\sqrt{2}+\sqrt{4 \left(1+\sqrt{2}\right) x+2}}{\sqrt{2 x+\sqrt{2}-1}} \\[1em] &\underset{\hphantom{(12)}}{=} -\sqrt{2 x+\sqrt{2}-1}+\frac{\sqrt{4 \left(1+\sqrt{2}\right) x+2}}{\sqrt{2 x+\sqrt{2}-1}} \\[1em] &\underset{\hphantom{(12)}}{=} -\sqrt{2 x+\sqrt{2}-1}+\sqrt{2 \left(1+\sqrt{2}\right)}. \end{align*} $$\tag*{\Box}$$ | {
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"openwebmath_score": 0.998802125453949,
"tags": null,
"url": "https://math.stackexchange.com/questions/2514441/minimize-min-f-in-e-left-int-01fx-dx-right"
} |
So it is possibly a good idea to let a machine do the counting, it seems to get only more complicated, with the limit of continous radius possibility for large $r$.
Please take the above graphics with a grain of salt: The solid graph is $f(r) = \frac{A(r)}{A_H} = \frac{\pi r^2}{2 \sqrt{3}}$ which is the area of the circumscribed circle expressed in hexagon cells. Due to the gaps at the rim, the number of hexagons (dots) is less than this ideal number. However the dots with the hexagon count for that radius seem too low, I need to hunt the bug and provide a version with corrected numbers.
• Sorry, i've a question for you: what software have used for make it? – Domenico M. Mar 13 '18 at 10:17
• I used GeoGebra. For the images with many objects I made use of GeoGebra's JavaScript facilities. – mvw Mar 14 '18 at 7:26
Posting the trivial estimates so that we can measure progress. | {
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"lm_q2_score": 0.8311430562234877,
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"openwebmath_score": 0.7562983632087708,
"tags": null,
"url": "https://math.stackexchange.com/questions/1283085/hexagon-packing-in-a-circle"
} |
c++, coordinate-system, linear-algebra
// Calculates projection of other to this, then stores the result in this (inplace)
template<typename T2>
constexpr vector& vector_projection_from(const vector<T2, Size>& other) {
T denominator = inner_product(*this);
// a null vector results in a scalar product of 0, thus a denominator of 0
// todo: decide whether this is the appropriate way to proceed, or whether another result can be given (eg. using limits)
ASSERT_DIV_BYZERO(denominator);
*this *= (inner_product(other) / denominator);
return *this;
}
// Return direction of a 2D vector. The vector components must be cartesian coordinates. x will return (angle)x,
// y returns (angle)y.
constexpr double direction_radiants_y() const
requires (Size == 2
and not is_complex<T>::value) {
return std::atan2(_vector[0], _vector[1]); // (x / y)
} | {
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c++, object-oriented, parsing
Don't Repeat Yourself (DRY)
The tests are all doing the same thing. That is, they apply some transformation to the input code and verify that the output is what was expected. Rather than repeating that same code multiple times, better would be to consolidate it into a single location:
class TestCollection {
std::string name;
std::string (*func)(const std::string&);
struct test {
std::string input;
std::string expectedResult;
};
std::vector<test> tests;
public:
TestCollection(std::string name, std::string (*func)(const std::string&), std::vector<test> tests) : name{name}, func{func}, tests{tests} {}
bool operator()() const {
bool result{true};
for (const auto& [input, expected] : tests) {
std::string result = func(input);
if (result != expected) {
result = false;
std::cerr << "Internal compiler error: " << name << " failed: \"" | {
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beginner, html, email, perl
I intend to make a host email script from this as well. It will be mostly the same except the main table will be displaying different variables. This is mostly about style.
Indent and align your code properly. This will save you a lot of time later when you have to go back to change stuff.
my $notificationType = '';
my $hostAlias = '';
my $hostAddress = '';
my $serviceDescription = '';
my $serviceState = '';
my $eventDateTime = '';
my $serviceOutput = '';
my $verbose = 0;
my $companyName = 'My Company';
my %ancillaryValues = (); | {
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"tags": "beginner, html, email, perl",
"url": null
} |
c++, windows, assembly
if (memorySlice[0] == 0xf6 && memorySlice[1] == 0x74 && memorySlice[7] == 0x75 && memorySlice[9] == 0x80)
{
locationsFound++;
si.stopFunctionLocation = ph.amnesiaMemoryLocation + i - 16;
}
else if (memorySlice[0] == 0x48 && memorySlice[8] == 0xd0 && memorySlice[9] == 0x5d)
{
locationsFound++;
si.isPlayingLocation = ph.amnesiaMemoryLocation + i - 17;
}
else if (memorySlice[0] == 0x75 && memorySlice[2] == 0x56 && memorySlice[4] == 0x15 && memorySlice[9] == 0x8b)
{
locationsFound++;
memcpy(si.sleepCallBytes, &memorySlice[3], sizeof(si.sleepCallBytes));
}
else if (
(memorySlice[5] == 0xff && memorySlice[6] == 0x50 && memorySlice[8] == 0xe8 && memorySlice[13] == 0x2b)
|| (si.isSteamVersion && memorySlice[5] == 0xff && memorySlice[6] == 0xd0 && memorySlice[7] == 0xe8 && memorySlice[13] == 0x45))
{ | {
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"openwebmath_score": null,
"tags": "c++, windows, assembly",
"url": null
} |
special-relativity, field-theory, gauge-theory, representation-theory, degrees-of-freedom
The point that you need to understand from that chapter is that the free equations of motion for fields are not something you can build by hand randomly or something you can play around with by adding new pieces or modifying old ones. Free equations of motion are 100% fixed by group theory. Even the more complicated looking equations, for example for a massive graviton, are just a sum of projectors on the right Poincaré representation needed for the particle you want to describe. In the vector case for example the equations of motion are equivalent to
$$(\square + m^2)A^\mu = 0 \\
\partial^\mu A_\mu = 0$$
In momentum space and in the center of mass frame ($p^\mu = (p^0,\vec 0)$), the first equation is telling you $p^2=(p^0)^2 = m^2$, while the second is $A^0 = 0$. That is you are projecting your field on-shell and keeping only the spin-1 component. | {
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electromagnetism, electrostatics, electric-fields
You can see the mistake immediately from the fact that your result doesn't have the right units - always always check your units!
So what changes? The discrete distribution produces a field that is larger by a factor of $\pi^2/6 \approx 1.6$. This makes sense: picture dividing the continuous line into segments of length $x$ and charge $q$. Going from this to the discrete distribution means concentrating all the charge of each segment at its left endpoint, thus moving it closer to the measurement point and strengthening the field. | {
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"tags": "electromagnetism, electrostatics, electric-fields",
"url": null
} |
tensorflow, image-classification, image-recognition
Title: Is it possible to make tensorflow print out everything it see in a given image and not just the top five results? I'm working through the python API tutorials for Tensorflow and I'm seeing the results that are normally displayed, but it's always giving me the top five results.
I'm trying to discern all possibilities within a certain list of basic attributes, like if I'm given a picture of a forest, I want to ask tensorflow if the picture contains oak trees, pine trees, bushes, rivers, etc. I don't need to know if the image is a picture of a forest. Is this possible? | {
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python, django
remove = SaveNumber.objects.get(phone_number=from_number)
remove.subscribed = False
remove.save()
except SaveNumber.DoesNotExist:
obj = SaveNumber(phone_number=from_number)
obj.save()
r1 = twiml.Response()
r1.message("Reply with stellar and you're in! :-)")
return r1 Here is my alternative. Your original code calls the DB for the same record twice (potentially) -- the get_or_create does the same as your try/except and creates the record.
def save_number(request):
from_number = request.POST.get('From', '')
subscribe = request.POST.get('Body', '').lower().strip()
obj, created = SaveNumber.objects.get_or_create(phone_number=from_number)
response = twiml.Response() | {
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The initial distribution is normalized, namely $$\int_{-\infty}^\infty {P_{init}(x)}dx=1$$, as it should.
However, it seems that no matter what T I choose, uval[x,T] never remains normalized.
Importantly: I get that uval[x,0] is different than Pinit(x), which is a contradiction.
How do I force Mathematica to solve the Fokker-Planck equation, whilst maintaining normalization?
Note that the reason that the integration boundaries are big, is since I would like to estimate the distribution at a long time, where the function might be much wider than the initial condition. This means that if I take boundaries which are too closely apart, I introduce mistakes because I force the function to be zero at a place and time where it shouldn't. | {
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"openwebmath_score": 0.41703495383262634,
"tags": null,
"url": "https://mathematica.stackexchange.com/questions/191081/how-to-preserve-normalization-in-ndsolve"
} |
sample proportion error
Sample Proportion Error p repeatedly randomly drawn from a population and the proportion of successes in each sample is recorded widehat p the distribution of the sample proportions i e the sampling distirbution can be approximated by a normal sample proportion formula distribution given that both n times p geq and n times -p p Standard Error Of Proportion Formula p geq This is known as theRule of Sample Proportions Note that some textbooks use a minimum of p Sampling Distribution Of P Hat Calculator p instead of The mean of the distribution of sample proportions is equal to the | {
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"lm_q1_score": 0.986777175136814,
"lm_q1q2_score": 0.8044528173522394,
"lm_q2_score": 0.8152324938410783,
"openwebmath_perplexity": 1098.8971632177004,
"openwebmath_score": 0.925527811050415,
"tags": null,
"url": "http://winaudit.org/guides/sample-proportion/standard-error-of-sample-proportion-formula.html"
} |
automata
(What I don't understand is the equivalence they mention, and how does that influence the acceptance of a word.)
If my statement (*) doesn't hold, how would I determine, given the definition of a DPA, which condition are input sequences supposed to fulfill? Would I assume one or the other as the preferred one? You can define the language of a PDA in two different ways:
For a PDA $M$, $L_1(M)$ is the set of all words which can be processed by $M$ in such a way that at the end, the stack is empty.
For a PDA $M$, $L_2(M)$ is the set of all words which can be processed by $M$ in such a way that at the end, $M$ is at an accepting state.
A basic theorem shows that both acceptance criteria are equivalent:
For each language $L$ the following holds: there exists a PDA $M_1$ such that $L_1(M_1) = L$ iff there exists a PDA $M_2$ such that $L_2(M_2) = L$. | {
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python, python-3.x, object-oriented, parsing, beautifulsoup
Title: Footwear scraper I've done this parser to scrape all footwear data, but I don't know if it is good to use OOP in this case. Can you please check this out and give me the strongest feedback? I'm working on improving my coding style and looking for an opportunity to do coding better. How can I make this parser more maintainable for the future?
#!/usr/bin/env python3
# coding=utf-8
import re
from datetime import datetime
from bs4 import BeautifulSoup
import http
import requests
import urllib.request
html_hdrs = {'User-Agent': 'Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.11 ('
'KHTML, like Gecko) Chrome/23.0.1271.64 Safari/537.11',
'Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8',
'Accept-Charset': 'ISO-8859-1,utf-8;q=0.7,*;q=0.3',
'Accept-Encoding': 'none',
'Accept-Language': 'en-US,en;q=0.8',
'X-Requested-With': 'XMLHttpRequest',
'Connection': 'keep-alive'} | {
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c#, async-await, rubberduck
private IEnumerable<QualifiedContext> _obsoleteCallContexts = new List<QualifiedContext>();
/// <summary>
/// Gets <see cref="ParserRuleContext"/> objects representing 'Call' statements in the parse tree.
/// </summary>
public IEnumerable<QualifiedContext> ObsoleteCallContexts
{
get { return _obsoleteCallContexts; }
internal set { _obsoleteCallContexts = value; }
}
private IEnumerable<QualifiedContext> _obsoleteLetContexts = new List<QualifiedContext>();
/// <summary>
/// Gets <see cref="ParserRuleContext"/> objects representing explicit 'Let' statements in the parse tree.
/// </summary>
public IEnumerable<QualifiedContext> ObsoleteLetContexts
{
get { return _obsoleteLetContexts; }
internal set { _obsoleteLetContexts = value; }
}
private readonly ConcurrentDictionary<VBComponent, IEnumerable<CommentNode>> _comments =
new ConcurrentDictionary<VBComponent, IEnumerable<CommentNode>>(); | {
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## 4. GCD
With the functions we defined, we're now ready to define GCD. Take the factors of x and the factors of y, intersect them to get their common factors, and then take the maximum thereof:
function Gcd(x: pos, y: pos): pos {
var common := Factors(x) * Factors(y);
Max(common) // error: common must be nonempty
}
For this simple definition, the verifier reports a precondition violation, because it's unable to prove that common satisfies the precondition of Max. We know that common is nonempty, because we know that 1 is a common factor of any two numbers x and y. To bring that information to the verifier's attention, we write an assertion:
function Gcd(x: pos, y: pos): pos {
var common := Factors(x) * Factors(y);
assert 1 in common; // error: assertion violation
Max(common)
} | {
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bar, y bar, and z bar). These formulas are only applicable if the centroid of a basic shape coincides with the centroid of the irregular. And I understand that to find the location of the centroid, we must analyze the distribution of the mass over the x and y axis (i. The centroid is the geometric center so the shape of the space will impact your results. OpenCV center of contour Figure 1: An example image containing a set of shapes that we are going to compute the center of the contour for. Examples of Image Analysis Using ImageJ (continued) Particle Counting and Analysis. So to find the x coordinate of the orthocenter, add up the three vertex x coordinates and divide by three. Test Your Knowledge!. | {
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"lm_q2_score": 0.8152324960856177,
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"openwebmath_score": 0.577366828918457,
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"url": "http://kjni.radiofakenews.it/how-to-find-centroid-of-a-shape.html"
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earth, saturn
Title: "If earth had rings like Saturn": A few further thoughts on the consequences I came across this video recently where artists depicted what it would look like if Earth had rings like Saturn. http://www.wimp.com/earthrings/
Please note: The video contains already some information on what I ask here, but I can't assess its reliability, therefore I'd appreciate any scientific thoughts on it :)
1) Earth has roughly a distance of 1 AU to the sun, Saturn between 9 and 10. Sun's gravity would therefore have a much stronger influence on these rings. Would it already be enough to distort the rings (e.g. even leading to the sun "stealing" parts of it) or would the rings still have a ring shape? | {
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c#, algorithm, pathfinding
// Node is present in queue and new optimal path is detected.
else if (newNode.TraverseDistance < existingNode.TraverseDistance)
{
frontier.Remove(existingNode);
frontier.Add(newNode);
}
}
}
}
}
Collections are defined inside class body, not inside methods: this way in subsequent calculations there will be no need in collection creation and resizing (assuming calculated paths are always have somewhat same length).
SortedSet and HashSet allows calculation to complete 150-200 times faster; List usage is miserably slow.
TryGetPathNodes() returns child node as out parameter; Calculate() iterates through all node's parents and returns collection of their positions.
I'm really uncertain about following things:
PathNode struct contains IPathNode reference. It doesn't seem normal at all. | {
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python, python-3.x, tkinter, pygame
def get_answer(): # Defines get_answer
if entry_characters.get() == word: # Tells program that if the entry of characters = the correct/incorrect
controller.show_frame("CorrectScreen") # Show correct screen (if answer is correct)
else:
controller.show_frame("IncorrectScreen") # Show incorrect screen (if answer is wrong)
def get_answer2(event): # Defines get_answer (event is needed so users can click enter when submitting)
if entry_characters.get() == word: # Tells program that if the entry of characters = the correct/incorrect
controller.show_frame("CorrectScreen") # Show correct screen (if answer is correct)
else:
controller.show_frame("IncorrectScreen") # Show incorrect screen (if answer is wrong) | {
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c++, asynchronous, thread-safety, c++20, boost
auto f = [
&,
completion_handler = std::forward<decltype(completion_handler)>(completion_handler)
]() mutable
{
auto completion_executor = asio::get_associated_executor(completion_handler);
static_assert(!std::same_as<decltype(completion_executor), asio::system_executor>, "system executor not allowed. Bind executor to your completion handler");
if (writers_allowed())
{
asio::post(completion_executor,
[
completion_handler = std::forward<decltype(completion_handler)>(completion_handler),
wlock = Write_Lock{*this}
] () mutable
{ completion_handler(std::move(wlock)); });
}
else
{ | {
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} |
c#, entity-framework, asp.net-web-api
public Asset() { }
public Asset(vwAsset asset = null, tblCustomer customer = null, tblCustomerLocation customerLocation = null, tblProduct product = null, tblBrand brand = null,
tblTagLocation tagLocation = null)
{
InitializeAsset(asset);
InitializeCustomer(customer);
InitializeCustomerLocation(customerLocation);
InitializeProduct(product, brand);
} | {
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algorithms, algorithm-analysis, time-complexity, sorting, radix-sort
Title: Total Number of Bits Needed to Represent a List of N elements This is an excerpt from the algorithms textbook How to Think About Algorithms by Jeff Edmonds (This book is a gem by the way).
I get his conclusion about Merge/Quick/Heap sorts having $O(NlogN)$ operations with respect to $N$, the number of elements in the input list, and at the same time they are linear in the context that they need $O(n)$ opertaions with respect to the number of bits needed to represent the input list. Different models of computation and a good way to describe one algorithm under different models.
But my question is in the line
Assuming that the $N$ numbers to be sorted are distinct, each needs $logN$ bits to be represented, for a total of $n = \Theta(NlogN)$ bits. | {
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topological-insulators, topological-phase
Title: Detection of topological phases In the book A Short Course on Topological Insulators (https://arxiv.org/abs/1509.02295) the authors start with a simple toy model, the SSH-Chain, which is a bipartite one-dimensional lattice with alternating hopping amplitudes $v$ and $w$. Its second quantized Hamiltonian is
\begin{equation}
\hat{H} = \sum_j v (b_j^\dagger a_j + a_j^\dagger b_j) + w (a_{j+1}^\dagger b_j + b_j^\dagger a_{j+1}),
\end{equation}
where $a_j$ resp. $b_j$ annihilate a particle at site $j$ of sublattice A resp. B. In momentum representation we may write this Hamiltonian as
\begin{equation}
\hat{H} = \sum_k \begin{pmatrix} a_k^\dagger & b_k^\dagger
\end{pmatrix}
\underbrace{\begin{pmatrix}
0 & v + w e^{ik}
\\
v + w e^{-ik} & 0
\end{pmatrix}}_{=H(k)}
\begin{pmatrix}
a_k
\\
b_k
\end{pmatrix}.
\end{equation} | {
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biochemistry, metabolism
Now let's turn to G6P and hexokinase in skeletal muscle. Hexokinase has a much higher affinity for glucose than hexokinase and will convert it efficiently to G6P. As long as G6P is then converted to G1P for glycogen synthesis, G6P will not build up. However when glycogen synthesis stops because the capacity of the muscle to store glycogen is reached, the concentration of G6P will increase and turn hexokinase off. This, in turn, will cause a build up of intracellular glucose and prevent glucose transport into the muscle. This makes sense, because with full glycogen stores, and in the absence of need for contraction, glucose will not be metabolized by the muscle; it will be left in the blood for the liver to handle.
Thus, the key point about G6P inhibition of hexokinase, and the apparent source of confusion in the question, is that it only occurs at concentrations that are reached when the G6P is not being metabolized within the cell.
Reference and Footnote | {
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c++, pathfinding, a-star
// Create the total_dist, dist_to_start, and heurist_dist_to_end values for the new subnode
// Calculated the total distance to the start by adding the distance from the subnode to the current node.
// Note: This distance could be precomputed and just held together with the "connections"
child.dist_to_start = current_node.dist_to_start + child.position.DistTo(current_node.position);
// Total cost is the sum of past distance and the heuristic (which assumes just line-of-flight)
child.total_dist = child.dist_to_start + child.position.SqrDistTo(end_node.position);
// Child is already in the open list
if (std::find_if(open_list.begin(), open_list.end(), [&child](const Node & node) { return((node == child) && (child.dist_to_start > node.dist_to_start)); }) != open_list.end())
continue;
// Add the child to the open list
open_list.emplace(child);
}
} | {
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"url": null
} |
Insight #3: But the Angles are bounded
The parabola didn’t always have Real solutions. In fact, Real x-intercepts (and thereby Real angle solutions) happened iff the discriminant was non-negative: $B^2-4AC=b^2-4*1*1 \ge 0$. In other words, the sum of the first two positive angles solutions for $y=(tan(x))^2-b*tan(x)+1=0$ is $\pi/2$ iff $\left| b \right| \ge 2$, and the sum of the first four solutions is $3\pi$ under the same condition. These results extend to the equalities at the endpoints iff the double solutions there are counted twice in the sums. I am not convinced these facts extend to the complex angles resulting when $-2.
I knew the answer to the now extended problem, but I didn’t know why. Even so, these solutions and the problem’s request for a SUM of angles provided the insights needed to understand WHY this worked; it was time to fully consider the product of the angles.
Insight #4: Finally a proof | {
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matrices. Convert the between polar and rectangular as needed. This software features an extremely clear interface, and it allows researchers to create reports, tables and graphs. Polar Coordinates. Practice now!. Slim, tough, soft options. The Precalculus course, often taught in the 12th grade, covers Polynomials; Complex Numbers; Composite Functions; Trigonometric Functions; Vectors; Matrices; Series; Conic Sections; and Probability and Combinatorics. The values of the dependent variable for each experimental trial are listed in the middle columns. 6 Polar Equations of Conics §6. pdf), Text File (. Keyword-suggest-tool. To go from the first point to the second, we go "up two and. ^ This cheat sheet is huge! :eek: The sys admins' compendium of cheat sheets, Polar Coords & Graphs Algebra Notes Exponents/Logs Area/Perimeter Surface Area/Volume Calculus. you’ll ever need to know in Calculus Objectives: This is your review of trigonometry: angles, six trig. After working with several | {
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Edit:
Does the boundedness of the $$\{f_n\}$$ come from the fact that every convergent sequence is a bounded sequence?
• to avoid confusing, you shouldn't write $\lim_{n\to\infty}\int_0^1f_n=\int_0^1f$ as $f$ is the initial function. – Leon Jan 4 at 9:40
• Is $f_n$ only "almost everywhere" converging? If so, can someone explain why? – Rem Jan 4 at 10:07
• @Rem Let fixed $y$. For every $x$, we have $\lim_n f_n(x)=\partial_y f(x,y)$. – Leon Jan 4 at 10:11
• @Leon So we make no assumption that it is only "almost everywhere" pointwise convergent, right? I understand that we don't need more than that for the proof though. – Rem Jan 4 at 10:19
• Yes, i think so. – Leon Jan 4 at 11:32
Consider $$y \in [0,1]$$ and any sequence $$y_n \in [0,1]$$ such that $$y_n \to y$$. By the mean value theorem, there exists $$\xi_{x,n}$$ between $$y$$ and $$y_n$$ such that | {
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} |
machine-learning, regression, optimization, gradient-descent, overfitting
Moving from linear models to more complex models, like deep learning, you're even more at risk of seeing overfitting. I've had plenty of convoluted neural networks that badly overfit, even though convolution is supposed to reduce the chance of overfitting substantially by sharing weights. In summary, there is no silver bullet for overfitting, regardless of model family or optimization technique. | {
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$$1+1 = 1+S(0) = S(1+0) = S(1)$$ Now replace $1$ with its "full form" of $S(0)$ and we have: $$S(0)+S(0) = S(S(0)+0) = S(S(0))$$
Which is what we wanted.
In a more general setting, one needs to remember that $0,1,2,3,\ldots$ are just symbols. They are devoid of meaning until we give them such, and when we write $1$ we often think of the multiplicative identity. However, as I wrote in the first part, this is often dependent on the axioms - our "ground rules".
If we consider, instead of the natural numbers, the binary digits $0,1$ with addition $\bmod 2$, then we have that $1+1=0$. Now you can argue that of course that $0\neq 2$, however in this set of axioms (which I have not expressed explicitly here) we can prove that $0=2$, where $2$ is the shorthand for $1+1$ and $0$ is the additive neutral element.
Actually, just writing $1+1=0$ is a proof of that. | {
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rotational-kinematics
You can find the final speed of the hoop after it rolls down a hill by conservation of energy using this formula for the kinetic energy.
If you have a mass in the center of the hoop, you can adjust the moment of inertia depending on the relative masses of the hoop and the thing at the center and continue to use the general equation for the kinetic energy of a mass distribution. You will find that the kinetic energy is still proportional to $mv^2$, but the constant of proportionality is less than one. Otherwise you may account for the mass at the center of the hoop separately in the expression for the energy. | {
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satisfiability, integer-programming, game-theory, optimal-strategy
I believe this encoding successfully represents the set of legal games, and enables with minimal additions asking questions like "What is the shortest/longest game" and "Is there a legal game with these constraints".
Where I'm struggling is handling adversarial behavior. I'm not sure how to ask questions like "can this player force a win" via integer programming. I suspect it may not be possible since SAT is in NP but many combinatorial games are in EXP, so the language might not be able to express (cleanly) the idea of an optimal sequence of play. But it may be possible that special cases like Nim (definitely not EXP) yield clever solutions. I can't find any literature on this. | {
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quantum-mechanics, observables
Title: Discrete Values for Observables vs Average Values (Quantum Mechanics) When considering observables and their corresponding operators, would it be correct to believe that discerning discrete values for an observable is possible ONLY when $\psi$ is an eigenfunction of the operator? Alternatively, would it also be correct to believe that the average value of an observable is ALWAYS obtainable regardless if $\psi$ is an eigenfunction of the operator?
Thanks for your help. I will try to answer from what I have understood so far.
Every Hermitian operator has a set of Linearly independent eigenvectors and hence we can use it construct a basis(provided it spans the space). Lets say say operator is $ \hat A $ and their eigenvector set $ \{\vert a_i \rangle\} $ with the eigenvalue equation,
$$ \hat A \vert a_i \rangle = a_i \vert a_i \rangle\ $$
Now we have an arbitrary state $ \vert \psi \rangle\ $and expand in the basis $ \{\vert a_i \rangle\} $ | {
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ros, gazebo, rviz, universal-robots
Title: Running a Universal Robot Urp or Script file from ROS PC
Hello,
Is it possible to run a Universal Robot Urp file or Script file from ROS PC to control a UR robot in the simulator(rviz/Gazebo)? The use case is that:
I have a program (URP file) that is used to move the robot without collision to the home position during a process. And now I want it to test this program for its functionality from anywhere in the work space. My idea is to make a ros visualization in rviz or gazebo and to initially move the robot to a random point in the work space and call the safety program from ros pc to detect any collision in the simulator. I can record all those points where a collision is detected and I can later correct the program if I want to prevent the collision in future.
Is it possible to do this. Please let me know your suggestions. Thanks.
Originally posted by npa on ROS Answers with karma: 5 on 2017-11-13
Post score: 0 | {
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number of angles or a given number of equal faces. 8) With endpoints of a diameter at (5, 9) and (-1, 3). Like always, pause this video and see if you can work through it on your own before we do it together. theorem 361. Sketch a graph of the function and the secant line through P and Q. 1 Use functional notation to evaluate a function. Studyres contains millions of educational documents, questions and answers, notes about the course, tutoring questions, cards and course recommendations that will help you learn and learn. Apart from the above forms of equation of straight line, there are some other ways to get equation of a straight line. Solver : Graphing Linear Equations by jim_thompson5910(35100) Solver : Finding the Equation of a Line Parallel or Perpendicular to a Given Line by jim_thompson5910(35100) Solver : Converting Linear Equations in Standard form to Slope-Intercept Form (and vice versa) by jim_thompson5910(35100) Want to teach? You can create your own solvers. (b) A | {
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image-processing, image-compression
Title: PNG IDAT specification I'm going over the W3 PNG specification (creating a PNG library from scratch) and I've finally found how to create a green 1x1 image.
Now I'm trying to create a bigger image of mixed Red, Green and Blue pixels. Let's say a 4x4 image. Sadly I'm getting all the pixels mixed and some of them are Black or Pink.
Details:
Signature: OK
IHDR: OK
Width: 4
Heigh: 4
Bit depth: 8
Color: 2
Filter: 0
Compression: 0
Interlace: 0
IDATA: 4 chunks*
IEND: OK
*IDATA chunks:
4 bytes length: Number of bytes of the DATA after Zlib deflate
4*1 byte type: IDAT
X bytes data: 4*4bytes unsigned integers, Zlib deflated, one after the other, Network byte order
255 for blue**
65280 for green**
16711680 for red**
4 bytes crc: OK
**Bitwise results of:
alpha<<24 | red<<16 | green<<8 | blue | {
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java, javafx
if(source instanceof MenuItem) {
clickedItem = (MenuItem)source;
} else {
return;
}
String id = clickedItem.getId();
if (this.userState.getUser() != null) {
switch (id) {
case "homeMenuItem":
this.changePage(this.home, new int[]{UserRanks.CASHIER.getValue(), UserRanks.SALES_EXECUTIVE.getValue(), UserRanks.MANAGER.getValue(), UserRanks.ADMINISTRATOR.getValue()});
break;
// ... | {
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To get to that conclusion, we need to know at least these two facts:
1. $(e^x)' = e^x$
2. what the function $\log$ is (in particular that it is a functional *inverse* of $\exp$).
Perhaps you show (or merely indicate the "plausibility" of) the fact that $e^0 = 1$. I would be *interested* in how you derive fact 1. There are some different ways to do this, and you haven't indicated which one you prefer. You also have not indicated how the number $e$ (rather than "some exponential function $\exp$") enters into this. I think that this is critical, since the whole POINT of your initial post is that $e$ represents a "special base".
Fact 2 also needs prior establishment of at least SOME facts about $e^x$ (like, that it is 1-1, so it *has* an inverse, contrast this with the contortions we must undergo for inverse trig functions). | {
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agrees with all combinations of truth. The Lord of Non-Contradiction: An Argument for God from Logic James N. p q _ TTT TFT FTT FFF In this module we will often use truth tables. In fact, the laws of logic stated in Section 3. Neff, 2018 1 Truth Tables Please do the following exercises individually. Note that if you claim that a proposition is a tautology, then you must argue( by using truth tables or otherwise) that it is true for every assignment of truth values to the propositional variables; if you claim that it is false for every assignment of truth values to the propositional variables; and if. ;) – user20153 Sep 18 '16 at 23:43. Use truth tables to explain why. This is an interesting option to consider, but then we might need to consider why the method of constructing truth tables tells us that the law of excluded middle holds, if it actually doesn’t. Is q implies p true for this row? Does true imply true? Yeah. Truth Table Description. Logically Equivalent Statements, | {
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python, python-3.x, clustering, natural-language-processing, scipy
print("Save detection to file? [Y][N]\n")
save = input()
save = save.upper()
if(save == "Y"):
filename = input("File name?\n")
file = open(filename, 'w')
file.write(detectLang(text))
file.close()
print()
else:
detectLang(text)
else:
flag = False
except(SyntaxError, TypeError, ValueError, NameError, ZeroDivisionError):
print("Invalid input! Try again...")
main() Welcome to Code Review!
This is an interesting program; thanks for sharing!
To help you maintain it ...
baseDict appears to be unused, and can be removed. Ditto for cosines | {
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### Tide
HINT: Start by comparing the weight of two groups of 4 keys.
3. Nov 27, 2005
### firstwave
Hmm, I don't think that works. If I compare two groups of 4 keys, there are 2 possible outcomes.
Either one side is different or both groups weigh the same. If the outcome is the former, I still need to use the scale once more to determine which one of the three groups contains the different key. The problem is that knowing which side is heavier or light does not necessarily help because we don't know if the "special" key is ligher or heavier than the other 11 keys.
Maybe I am perceiving this wrong, so please enlighten me :)
4. Nov 27, 2005
### Tide
Okay,
If the two sets of four do not balance then you eliminate the third (unweighed) set so we'll set them aside. | {
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forces, fluid-dynamics, rotation, biology
However in many applications other units are used because they are more convenient, and in particular in rheology it's common to use the centimetre-gram-second system. In this system shear stress has the units of dynes per square centimetre, and viscosity has the units of Poise.
So your units are fine as they are, though remember to use the viscosity in poise not centipoise. The angular velocity has the units $s^{-1}$, which is fine, and the angle is dimensionless. | {
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optics, refraction, mathematics
Look up the derivation of Snell's law in either Section 1.5 of Born and Wolf, "Principles of Optics" or look at my sketch of a proof in my answer here. | {
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python, beginner, game, pygame, snake-game
if 200:
pygame.draw.rect(game_display, YELLOW, [left_bombs_x[0], left_bombs_y[0], block_size, block_size])
pygame.draw.rect(game_display, YELLOW, [left_bombs_x[1], left_bombs_y[1], block_size, block_size])
pygame.draw.rect(game_display, YELLOW, [left_bombs_x[2], left_bombs_y[2], block_size, block_size])
pygame.draw.rect(game_display, YELLOW, [left_bombs_x[3], left_bombs_y[3], block_size, block_size])
if score >= 300:
pygame.draw.rect(game_display, YELLOW, [down_bombs_x[0], down_bombs_y[0], block_size, block_size])
pygame.draw.rect(game_display, YELLOW, [down_bombs_x[1], down_bombs_y[1], block_size, block_size])
pygame.draw.rect(game_display, YELLOW, [down_bombs_x[2], down_bombs_y[2], block_size, block_size])
pygame.draw.rect(game_display, YELLOW, [down_bombs_x[3], down_bombs_y[3], block_size, block_size])
if score >= 500: | {
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thermodynamics, water, heat, renewable-energy
$$\Delta T_{tank} = \frac{0.14 K/s \times 3600 s/h \times 6 h}{200} \approx 15 K$$
So a $4m^2$ system would give you $\Delta T_{tank} \approx 60 K$ . Then that would get derated, based on system losses, including thermal losses from the collector plate and the thermal store.
Heat loss from the panel itself will (broadly) be proportional to the difference between the heat-transfer fluid, and the ambient air temperature - that gives the tapering you mentioned.
And you'll need a figure for the rate at which heat can be exchanged between the heat-transfer fluid that passes through the collector, and the thermal store.
(See also Appendix H of SAP 2009 which starts on pdf p73 - but bear in mind that that's a coarse static approximation of a solar thermal system in the UK, not a dynamic simulation - but it has some figures to get you started on collector efficiency and thermal losses) | {
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quantum-mechanics, quantum-entanglement, quantum-interpretations
Title: Is there a difference between observation and entanglement? I have very basic knowledge about quantum mechanic. I started wondering if there is any difference theoretically between observation and entanglement between subject and object.
I.e. if we simplify an observer state to q-bit and initial state of second is $\alpha\left|0\right> + \beta\left|0\right>$ then observation can be roughly represented as:
$$\left|0\right> \otimes \left(\alpha\left|0\right> + \beta\left|1\right>\right) \to \alpha\left|00\right> + \beta\left|11\right>$$
(Unless I'm missing something this is unitary operation)
That should behave from 'POV' of left q-bit as-if the measurement was $\left|0\right> $ or $\left|1\right>$ respectively (sort of like in multiple worlds instead of splitting the words the observer becomes in quantum state). [Of course most scientist are represented by slightly more complex state then one q-bit ;) ] | {
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committee announces that your ramp is too steep ; it has to be measured is at right. Angles can go together to create the total number of degrees of the central is... Measurement directly off the protractor North star in the school supply section of big box.. A reflex angle measures, see the line for the challenge, knock yourself out. ) a degree... Sure that your measure is close to your estimate by its measure your own protractor... Got it down: one degree is the degree symbol angle doesn ’ t reach the scale you.. T reach the scale that begins with zero do if your math how to measure angles in degrees are a little math but... Is too steep ; it has to be measured is at the point where the sides of the or... A minute with measuring an angle by degrees, minutes, seconds calculators near bottom. Reasoning and Problem Solving with answers of interesting angles to think about but do n't if... Line AC lining up one ray along the circumference of a regular pentagon is equal to 180 within... | {
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ros, python, move-group, trac-ik
Title: Using correct solve_type when running code
This question is related to one I posted earlier: http://answers.ros.org/question/265135/moveit-using-solve-type-speed-instead-of-distance/. MoveIt! currently launches correctly with solve_type: Distance, which is the solve type I want. However, when I run a Python script to issue move commands, it still uses solve_type: Speed:
[ INFO] [1499261352.380466647]: Looking in private handle: /move_group_commander_wrappers_1499261351880510562 for param name: manipulator/position_only_ik
[ INFO] [1499261352.381577584]: Looking in private handle: /move_group_commander_wrappers_1499261351880510562 for param name: manipulator/solve_type
[ INFO] [1499261352.382617524]: Using solve type Speed | {
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complexity-theory, classical-computing, cryptography
Title: Has the possibility of there being a classical cryptography algorithm able to withstand quantum computing been proven? Has it been proven, that a classical codec (encoder-decoder) (classical meaning one that doesn't require a quantum system for its operation) is possible, such that a quantum computer cannot crack it? | {
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general-relativity, differential-geometry, tensor-calculus, curvature
The factor $k_i$ in arc length can be regarded as the deviation from Euclidean space. In a small enough region, the space becomes close Euclidean ($k_i \approx 1$). Curvature corresponds to the second derivative of $k_i$ as radius $R_i$ goes to zero. For a two dimensional space, two directions and magnitudes are necessary. In four dimensional spacetime four are needed, meaning a rank-4 tensor, Riemann. Contract with two indices and that gives you Ricci, and contract the remaining two indices to get scalar curvature. | {
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performance, beginner, c, memory-management, vigenere-cipher
int txtlen = strlen(plaintext);
int keylen = strlen(key);
// This allocates and should be freed. Arguably better to
// simply malloc and clear. May be NULL on error
*ptr_ciphertext = strdup(plaintext);
if (*ptr_ciphertext) {
for(int ii = 0; ii < txtlen; ++ii) {
// Modulus keylen indexes into key repeatedly over range [0, keylen)
*ptr_ciphertext[ii] = rotate(plaintext[ii], key[ii % keylen]);
}
}
}
int main (int argc, char **argv) {
// Validity checks.
// Verify count before dereferencing argv.
if (argc != 2 || !is_valid_key(argv[1])) {
printf("Error: Not valid input!\n");
return 1;
}
char *plaintext = get_string();
if (plaintext == NULL) {
return 1;
} | {
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notation
Which is all to say: I would read the equation you wrote as saying that the LHS is greater than something of similar size to the right hand side. So it might not be greater than, say, $10^9 \left( |i| - |o| \right)$ but the idea is that there's probably some constant attached to the front that isn't important for the relation being stated, and the method we used to calculate it might not give a reliable answer for that constant. | {
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javascript, programming-challenge, functional-programming
Is "tree recursive" and therefore does a lot of extra work. Tree Recursion is described in The Structure and Interpretation of Computer Programs. Section 1.2.2 has a very helpful illustration that shows how tree recursive algorithms wind up performing substantially more work than is necessary.
Alternative Functional Approach
Recursive Design: Structurally recursive algorithms have two part: a base case and an inductive step. The naive approach to Fibonacci treats n == 0 as the base case and n-1 as the induction. The alternative code treats n as the base case and n + 1 as the induction. This means n - 1 has always been computed previously.
function sumOfEvenFibsLessThan (n) {
/* Returns the array of Fibonacci numbers less than n */
var fibsLessThan = function (n) { | {
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mvc, objective-c, ios
// Check if the contact has multiple phone numbers
BOOL result = [contact hasMultiplePhoneNumbers];
// If contact only has one phone number, then add the
// number from the phoneNumbers property into the
// contact's mainPhoneNumber property
if (!result) {
contact.mainPhoneNumber = contact.phoneNumbers[0];
// Add contact to friends array
[self.friends addObject:contact];
continue;
}
// Loop through the contacts phone numbers
// and for every phone number, create a copy of the contact
// and place the current phone number at index in
// the copy's mainPhoneNumber property.
// So if "Steve" has 2 phone numbers, he'll be added to our
// friends array twice, once for each phone number. | {
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ros
Comment by kowais915 on 2023-05-04:
Mine is ttyUSB0 too. I have given all the rwx permissions too. I tried powering the pi using a powerbank as well but I am still getting the same error.
Comment by Mike Scheutzow on 2023-05-04:
Which machine are you running that roslaunch command on?
Comment by kowais915 on 2023-05-04:
The lidar is connected to raspberry pi 3 Model B+ that has ROS noetic installed. I have connected to the pi via ssh from another machine that has ROS noetic running as well. I have installed Ubuntu 20.04 via WSL2.
So I am technically running the roslaunch command on PI but via SSH on another machine.
I have been searching for everything. At this point, I am so frustrated.
Comment by Mike Scheutzow on 2023-05-04:
Using ssh in that way should be fine. The error message indicates that your ros node (rplidarNode) finds some device on the serial port, but the node is either unable to read from the device, or the values do not match the rplidar model it is looking for. | {
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heat, temperature, everyday-life, thermal-conductivity
power of its cooling engine (I do not know whether that is the case),
then the heat pump will pump more heat per second when the fridge is warm.
Hence it is better to put all bottles at once and get the fridge
warmer to have a maximum heat pumpimg capacity from the heat pump.
Heat sharing rate within the fridge may also be an important issue, but there are no data available to measure how important. If it is really low, thus leaving an important temperature gradient in the fridge, it may be useful to exchange the position of bottles, so as to have the warmer part of the load
near the heat pump and have work with highest possible coefficient of performance.
Precise figures about the load do not matter very much. However, a load with large heat capacity will take longer to cool and will thus allow more time for heat sharing. | {
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microscopy
And yes: you need to use immersion oil with the 100x objective, but keep in mind this is a very demanding objective to be used, on the part of the microscopist as well as on the part of the slide preparer.
Using a microscope is not all that simple for novices, but there's an easy way to find out -if no image can be produced-, if it's a microscope problem or an inexperienced user problem: take as a specimen an as thin as possible large object, such as a leaf of cigarette paper, and try to focus on it, using low power and gradually use stronger objectives up to 40/0.65. If an image can be produced, even if it's rather blurred at 40/0.65, the microscope is okay. | {
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EDIT
If you don’t have equal probability of each number, the calculation can be modified. I’ll do the case where the human is not necessarily good at picking numbers with uniform probability of each number. Again, assume independence of the guess and the roll.
$$P(Roll = n) = 1/20\\ P(Guess = n) = p\\ P(Roll = n \text{ AND } Guess = n) = p/20\\ P(Roll = n \vert Guess = n) = \dfrac{P(Roll = n \text{ AND } Guess = n)}{P(Guess = n)} = \dfrac{p/20}{p} = 1/20$$
If also the d20 is not fair:
$$P(Roll = n) = p_1\\ P(Guess = n) = p_2\\ P(Roll = n \text{ AND } Guess = n) = p_1p_2\\ P(Roll = n \vert Guess = n) = \dfrac{P(Roll = n \text{ AND } Guess = n)}{P(Guess = n)} = \dfrac{p_1p_2}{p_2} = p_1$$
So it only depends on the probability of rolling a particular number. | {
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You exactly want to determine the clique number of the generalized Kneser graph $KG_{n,k,s}$ for $s=1$, which is the graph having all the $k$-element subsets as its $\binom{n}{k}$ vertices, where any two vertices are connected if and only if their cut contains at most $s$ elements. Thus, a maximum clique of $KG_{n,k,1}$ is a maximum selection of $k$-element subsets such that all their pairwise cuts are singleton or emtpy. The size of such a maximum clique is the clique number $\omega(KG_{n,k,s})$.
Googling around a bit, I could not find an exact expression therefore.
However, this states that $\omega(KG_{n,k,0}) = \lfloor \frac n k \rfloor$. Since for $s > 0$ edges are never removed, this also gives a lower bound on $\omega(KG_{n,k,s})$ for any $s \geq 0$, thus, $\omega(KG_{n,k,1}) \geq \lfloor \frac n k \rfloor$. But this bound seems rather weak, since it does not respect any singleton edges at all. For your example above we get 1,1,1,2,2,2,3 as lower bounds on 1,1,2,4,7,7,12. | {
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php, mysql, authentication
In your "login form" code you have:
$password = password_hash($_POST['password'], PASSWORD_DEFAULT);
You have literally defined how you are hashing passwords in a script that is supposedly for "login form". If you need to hash a password somewhere else, you'll have to copy it there, and then you have it defined in two places.
If you ever need to change how you hash passwords (unlikely but rule applies across the board however unlikely) then you need to seek out all the places you did the above and change it. Hoping you got them all and don't leave a bug or worse, a little security hole...
So another decouple example from the above:
In a separate file:
function hashPassword($passwordToHash)
{
return password_hash($passwordToHash, PASSWORD_DEFAULT);
}
Then anywhere you need to know a password's hash value:
$password = hashPassword($_POST['password']; | {
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electrostatics, electric-fields, gauss-law
Using Gauss's law I found $$E(r)= \begin{cases} \frac{r \rho}{2\epsilon_0} \quad \mbox{ if $r\leq a$} \\ \frac{a^2\rho}{2\epsilon_0 r} \quad \mbox{if $a\leq r<b$} \\ 0 \quad \mbox{ . .if $b<r$} \end{cases}$$ but what happen at $r=b$? Should I understand "the charge enclosed by the gaussian surface" as the charge in the interior of the volume having as frontier that surface or it does incude the charge in the surface itself? In the first case it would be $E(b)=\frac{a^2\rho}{2\epsilon_0b}=\frac{-\sigma}{\epsilon_0}$ while in the second one it would be just zero. Which one is the right interpretation? A surface charge induces a discontinuity in the electric field normal to the surface (see also this question). So at $r=b$, there are, so to speak, two field values, depending on which direction you approach the surface from. This is, in the end, unphysical and it comes from an unphysical assumption in our modeling: there are no surfaces that have no volume but contain charges in nature - | {
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python, type-hinting
is [Number] better than Complex or Real?
No.
When authoring a function, only make promises you can keep.
That is, promises which you have already verified, in your automated test suite,
and which you are willing to take support calls for.
Suppose that update_prices, or some downstream consumer of its result,
wants to round() a price to the nearest Euro.
This works for Decimal, Fraction, float, and int.
But it blows up horribly for Complex.
Even if it doesn't, when we ignore rounding,
simple text formatting operations are likely to yield surprising results
when diverse input types are attempted.
Beyond exceeding a column width, we may run afoul of regexes
that try to parse "numeric" data using too small of a character set.
Often a software engineer gets to design the rules a system will play by.
The Robustness Principle asks you to write robust code.
If you craft conservatively simple rules, your system will be more robust. | {
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java, algorithm, pathfinding, sliding-tile-puzzle, priority-queue
@Override
public List<PuzzleNode> search(PuzzleNode source, PuzzleNode target) {
Objects.requireNonNull(source, "The source node is null.");
Objects.requireNonNull(target, "The target node is null.");
processTarget(target);
Queue<NodeHeapEntry> OPEN = new PriorityQueue<>();
Set<PuzzleNode> CLOSED = new HashSet<>();
Map<PuzzleNode, PuzzleNode> PARENTS = new HashMap<>();
Map<PuzzleNode, Integer> DISTANCE = new HashMap<>();
OPEN.add(new NodeHeapEntry(source, 0));
DISTANCE.put(source, 0);
PARENTS.put(source, null);
while (!OPEN.isEmpty()) {
PuzzleNode current = OPEN.remove().node;
if (current.equals(target)) {
return tracebackPath(target, PARENTS);
}
if (CLOSED.contains(current)) {
continue;
}
CLOSED.add(current); | {
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"tags": "java, algorithm, pathfinding, sliding-tile-puzzle, priority-queue",
"url": null
} |
ros, navigation, turtlebot
For instance, make sure your understand the basics and fundamentals of ROS before start concerning how to program your turtlebot.
Go through the ROS tutorials and make sure to understand what are the meanings of nodes, topics, messages, launch files, listeners, and publishers. Just try to get the big picture!
Try to understand how to configure your CMakeLists.txt and your package.xml
User Eclipse or QTCreator as an IDE for your project, instead of using a text editor for writing your code)
Divide your project into many stages (start with the easier stages and move on to the the more difficult as your ROS skills improve)
Whenever you face a problem, do not hesitate to ask questions on ROS Answers. So many ppl will be glad to help (as long as you show them you tried and put efforts to solve the problem). | {
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electrons, atoms, electronegativity, polarity
This thinking was established as molecular orbital theory (s orbitals, p orbitals, ...). There have been other models before, e.g. you might know the shell model (k shell, l shell, ...). For experimental evidence you might want to take at look at this -- but most of all the citations therein: http://en.wikipedia.org/wiki/User:Chem507f10grp4/sandbox#Experimental_Evidence_Supporting_Molecular_Orbital_Theory
Basically, the shell model ran into a series of properties it did not calculate correctly or precisely. Molecular orbital theory was found to predict many properties and came to well calculated values. | {
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statistical-mechanics, ideal-gas, fermions, chemical-potential
$$n\simeq\frac {1}{ \pi^2} \left(\frac{T}{\hbar c}\right)^3\frac 16\left(\frac {\mu}{T}\right)^3\left(1+\pi^2 \left(\frac T{\mu}\right)^2\right)\simeq \frac {V}{ 6\pi^2} \left(\frac{\mu}{\hbar c}\right)^3 \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ T\rightarrow0^+ $$
Which gives :
$$\mu \simeq \hbar c\left(6 \pi^2 n\right)^{\frac{1}{3}} \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ T\rightarrow0^+ $$ | {
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} |
energy, semiconductor-physics, atoms, ions
Title: What is the difference between band gap and first ionisation energy? To me both the band gap and first ionisation energy seems to be the same thing as both are the energy required to remove the valence electron from the atom. So I am confused whether they b are the same thing referred to by different names in physics and chemistry . I searched on the internet but I couldn't find any convincing answer. So my question is what is the difference between band gap and first ionisation energy?
Are they the same thing? | {
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quantum-mechanics, operators
Now, since the eigenbasis of the number operator $\hat{n} = \hat{a}^\dagger\hat{a}$ corresponds to the Fock states $\{|n\rangle\}_{n\in\mathbb{N}}$ and given that the coherent state $|\alpha\rangle$ is represented by $e^{-\frac{1}{2}|\alpha|^2} \displaystyle\sum_{n\ge0} \frac{\alpha^n}{\sqrt{n!}} |n\rangle$ in that basis, one has :
$$
|\psi(t)\rangle
= e^{-i\hat{H}t/\hbar}|\alpha\rangle
= e^{-\frac{1}{2}|\alpha|^2} \sum_{n\ge0} \frac{\alpha^n}{\sqrt{n!}} e^{-i\omega t\, \hat{a}^\dagger\hat{a}}|n\rangle
= e^{-\frac{1}{2}|\alpha|^2} \sum_{n\ge0} \frac{(\alpha e^{-i\omega t})^n}{\sqrt{n!}} |n\rangle
= |\alpha e^{-i\omega t}\rangle,
$$
hence
$$
\langle\hat{q}\rangle
= \langle\psi(t)|\hat{q}|\psi(t)\rangle
= \langle\alpha e^{-i\omega t}| \frac{\hat{a}^\dagger+\hat{a}}{\sqrt{2}} |\alpha e^{-i\omega t}\rangle
= \frac{\alpha^*e^{i\omega t} + \alpha e^{-i\omega t}}{\sqrt{2}},
$$
where $\hat{a}^\dagger$ has been applied on the left and $\hat{a}$ on the right. | {
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redox, organic-oxidation
Title: Oxidation of Sodium Hydroxide in Ethanol? So I read recently that:
Alcoholic solutions of sodium hydroxide will oxidize in air, turning brown.
First is this true?
And if so what is oxidizing?
I can't think of what sodium hydroxide would oxidize to, and ethanol well wouldn't that oxidize to water and CO2! [Answer based on comments from @KemonoChen, @IvanNeretin and @NilayGhosh. Thanks for your input :D]
In the presence of alkali (or acid, for that matter) aldehyde will
turn against itself, creating all matters of ugly polycondensate
products. See Aldol
condensation and
note that it ends up in another aldehyde, so the process can and will
be repeated
So yes it can happen.
And is is most likely ethanol oxidation to an aldehyde, which has (aldol) condensed into an 'ugly polycondensate'
It may also be Sodium Alkoxide, which is known to turn brown. | {
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c#, design-patterns, unit-testing, dependency-injection, repository
Bindings definition in the job:
public class FetchJobModule : NinjectModule
{
public override void Load()
{
Bind<IUnitOfWork>().To<UnitOfWork>();
Bind<IAggregatorContext>().ToFactory(() => new AggregatorContextProvider());
Bind<IFetchJob>().To<FetchJob>().InSingletonScope();
Bind<IArticleParser>().ToProvider<ArticleParserProvider>();
}
}
public class ArticleParserProvider : IProvider
{
public object Create(IContext context)
{
// looking for a ISource parameter in context chain
var currContext = context as Ninject.Activation.Context;
IArticleSource source = null;
while (currContext != null)
{
var sourceParam = currContext.Parameters.SingleOrDefault(p => p.Name.Equals("source"));
if (sourceParam != null)
{
source = (IArticleSource)sourceParam.GetValue(currContext, null);
break;
} | {
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"url": null
} |
gazebo
* /move_base_node/global_costmap/base_scan_marking/clearing
* /move_base_node/global_costmap/base_scan_marking/data_type
* /move_base_node/global_costmap/base_scan_marking/expected_update_rate
* /move_base_node/global_costmap/base_scan_marking/marking
* /move_base_node/global_costmap/base_scan_marking/max_obstacle_height
* /move_base_node/global_costmap/base_scan_marking/min_obstacle_height
* /move_base_node/global_costmap/base_scan_marking/observation_persistence
* /move_base_node/global_costmap/base_scan_marking/sensor_frame
* /move_base_node/global_costmap/base_scan_marking/topic
* /move_base_node/global_costmap/global_frame
* /move_base_node/global_costmap/inflation_radius
* /move_base_node/global_costmap/map_type
* /move_base_node/global_costmap/observation_sources
* /move_base_node/global_costmap/obstacle_range
* /move_base_node/global_costmap/publish_frequency
* /move_base_node/global_costmap/raytrace_range
* /move_base_node/global_costmap/robot_base_frame | {
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matrices, as well as. These are called eigenvectors (also known as characteristic vectors). For example, let's examine the following electrical circuit (resistors are in ohms, currents in amperes, and voltages are in volts). …When college mathematics departments offer…a linear algebra course, courses are typically taught…using a theoretical perspective. For example, let a set consist of vectors u , v , and w. 2 Linear Equations 6 3 Matrix Algebra 8 4 Determinants 11 5 Eigenvalues and Eigenvectors 13 6 Linear Transformations 16 7 Dimension 17 8 Similarity and Diagonalizability 18 9 Complex Numbers 23 10 Projection Theorem 28 11 Gram-Schmidt Orthonormalization 29 12 QR Factorization 31 13 Least Squares Approximation 32 14 Orthogonal (Unitary. Dozens of applications connect key concepts in linear algebra to real-world examples in Physics, Chemistry, Circuits, and more. MA1 Encourage including common computer science examples in linear algebra classes (e. Therefore, the tools from linear | {
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"url": "http://hpbk.rciretedimpresa.it/linear-algebra-examples.html"
} |
classical-mechanics, lagrangian-formalism, reference-frames, potential-energy, centrifugal-force
Title: Deriving effective potential energy from the Lagrangian of a two-body system I'm having some issues understanding how the effective potential energy of a two-body system is derived from the Lagrangian of the system. Specifically my issue is with one step...
Suppose we are analyzing the system in the centre of mass frame with a reduced mass $\mu$, radial separation $r$, and angular speed $\dot{\phi}$. Then the Lagrangian can be expressed as:
$$\mathscr{L}= \frac{1}{2}\mu(\dot{r}^2+r^2\dot{\phi}^2)-U(r)$$
I understand that $\phi$ is a cyclic coordinate, since $\frac{\partial \mathscr{L}}{\partial \phi}=0$
, and thus the angular momentum $l$ is conserved. Since
$l=\mu r^2 \dot{\phi}$
, we can use this to substitute in for
$\dot{\phi}$
and make the Lagrangian one-dimensional.
My problem is this: if we substitute in the
$\dot{\phi}$ | {
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beginner, c, file, image
Comments like // for strlen, strcopy are a pain to maintain. I recommend dropping that for standard headers.
No computational check
sizeof(*image->data) * image->header.image_size_bytes lacks overflow protection. Be very careful with external data from files that can cause undefined behavior with mis-szied allocation. Watch out for .image_size_bytes == 0 as the allocation may be NULL (which is not a "Not enough memory", but other concern).
uint64_t sz = image->header.image_size_bytes
sz *= sizeof(*image->data);
image->data = NULL;
if (sz <= SIZE_MAX) {
image->data = malloc((size_t) sz);
}
if (image->data == NULL && sz > 0) {
// assign error
}
free() style
free() tolerates free(NULL) and so I recommend to do so here with free_bmp(BMPImage *image)
void free_bmp(BMPImage *image) {
if (image) {
free(image->data);
free(image);
}
} | {
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ros, gazebo, turtlebot, camera, multiple
<arg name="init_pose" value="-x -1.5 -y 0 -z 0" />
<arg name="robot_name" value="Robot2" />
</include>
</group>
</launch> | {
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quantum-mechanics, statistical-mechanics, many-body
That said, the bosonic case $S=a^\dagger a$ is obviously problematic, because the transformed hamiltonian in $(1)$ is unbounded from below. as soon as you have one nonzero $g_k$. However, I think this is a problem with $H$ itself rather than the transformation.
To see this, consider the case where a single $g_k$ is nonzero, so
$$
H=\omega_s a^\dagger a+(gb+g^*b^\dagger)a^\dagger a +\omega_b b^\dagger b.
$$
Consider further the state $|\chi⟩=|n⟩|-n g/\omega_b⟩$, i.e. the number state $|n⟩$ tensor-times a coherent state at $-ng/\omega_b$ for the bath, and calculate its energy expectation value:
\begin{align}
⟨\chi|H|\chi⟩
&=
\omega_s n
+n(g(-ng/\omega_b)+g(-ng/\omega_b))
+\omega_b|ng/\omega_b|^2
=
\omega_s n-n^2g^2/\omega_b.
\end{align}
This is arbitrarily negative for sufficiently large $n$, which proves that there is no ground state with finitely negative energy. | {
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c#, beginner, unit-testing, homework, nunit
Title: Unit testing a CharGrid I wrote NUnit tests for class CharGrid from this homework assignment.
My goal here is DRY: I want to keep the testing code as short and simple as possible. In addition, want to run every test independently, as opposed to having a single method with a lot of asserts that either succeeds or fails as a whole.
I went through the NUnit documentation and found this "Parameterized TestFixture" annotation, which seemed to help fulfill my goal.
I would like to ask if there are any improvements to the testing code regarding what I just stated my goals were.
In addition, I would like to know if it is a good idea to have a separate CharGridTestFixture class or if it is preferable to directly annotate class CharGrid with a TestFixture and it's methods with TestCaseSource annotations and test them sort of in-place. This way there would be one less class. | {
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acoustics, mass-energy
Title: Calculating the mass equivalency of a song? I've recently become fascinated with the idea of sound energy having a theoretical equivalent mass. I've read over this thread:
Do light and sound waves have mass
I understand this part: $m_{eq}=E/c^2$ and $E=A\rho \xi^2\omega^2$
Where I am getting tripped up is the way to measure $E$.
Essentially, I want to measure $E$ and eventually $m$ of a song (for it's entire duration). The only equipment I have is an iPhone app that measures intensity (dB) (apparently it's fairly accurate for levels below 100 dB). I plan to play the "music" at about 80dB over speakers in a room that is 50'x30'x15' and I will assume the temperature is at room temperature. If your wondering, it's for a conceptual audio art piece. A song has no mass equivalence. The sound waves from playing a song do---to the extent that they carry energy, and you can relate an equivalent mass1 to energy. | {
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coordination-compounds, spectroscopy, ir-spectroscopy
Title: Stretching frequency of nitro and nitrito I got the values of the stretching frequency of nitro and nitrito ligands from this webpage.
I understand why stretching frequencies are close in nitro and well separated in nitrito. How to explain why nitrito has slightly higher stretching frequency? First of all, in the webpage, I think there is some shuffling between Nitro and Nitrito first in the headline. But, according to the contents, Nitro has closer stretching frequency, but Nitrito has distinguished stretching frequency.Let's take that one as the correct data. | {
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organic-chemistry, reaction-mechanism, carbonyl-compounds, alcohols, organic-oxidation
Zerong Wang, "Malaprade Reaction (Malaprade Oxidation)," In Comprehensive Organic Name Reactions and Reagents; John Wiley & Sons, Inc.: New York, NY, 2010 (https://doi.org/10.1002/9780470638859.conrr406). ISBN: 9780471704508.
Fathia Mohammed Ibrahim, Mubark Elsayed Osman, "Elucidation of Sugars Structure through Periodic Acid Oxidation Cleavage," International Journal of Science and Research (IJSR) 2018, 7(1), 1152-1155 (https://www.ijsr.net/search_index_results_paperid.php?id=6121702)(PDF)
G. J. Buist, C. A. Bunton, J. H. Miles, “149. The mechanism of oxidation of α-glycols by periodic acid. Part V. Cyclohexane-1 : 2-diols,” J. Chem. Soc. 1959, 743-748 (https://doi.org/10.1039/JR9590000743). | {
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"tags": "organic-chemistry, reaction-mechanism, carbonyl-compounds, alcohols, organic-oxidation",
"url": null
} |
genetic-algorithms, packing
Title: Genetic algorithm - fit max circles inside box - what chromossomes? I am using a genetic algorithm to fit the max number of circles into a box. Right now my cromossomes are both coordinates of the each circle. I am not sure how to crossover and mutate the x and y coordenates in order not for the to converge but to keep a distance.
Can someone please shed some light? Thank you
This is where I am getting at:
Now I am getting this:
But there is the last ball always overlaps. I think my problem is with the crossover.
So far and by gathering all the ideas here this is what I have reached:
Given a fixed number of circles (easier to explain) this is what I am doing.
Create a random set of circles for each individual in the population | {
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javascript, jquery, html, ajax
<tr>
<td nowrap="nowrap" style="padding-left:20px;" class="BodyText">
<b><a href='jobs.aspx?id=3585&type=1&int=External'>Secondary Teachers - 2013SecPool</a></b>
<br/>
<b>Location:</b>TBD<br/>
<b>Contract:</b>State Salary Schedule DOE & Credits<br/>
<b>Anticipated Hours:</b> <br />
<b>Posting Date:</b> 1/9/2013
<b>Closing date:</b> Until Filled | {
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"tags": "javascript, jquery, html, ajax",
"url": null
} |
coords=polar , parametric plots produces polar plots. An image on a graph is said to be parametrized if the set of coordinates (x,y) on the image are represented as functions of a variable, usually t (parametric equations are usually used to represent the motion of an object at any given time t). Find the total length of this curve correct to four for Teachers for Schools for Working Scholars for. Finding the maximum absolute value of r and the θ values for which r = 0 is also a useful technique in sketching and analyzing the graph of a polar equation. Woody's entire body in Toy Story is a collection of parametric surfaces. cycloid, a variety of more advanced mathematical topics -- such as unit circle trigonometry, parametric equations, and integral calculus -- are needed for any real mathematical understanding of the topic. Graphing Calculator 4. Solution: The parameter value corresponding to the point is , so Therefore the parametric equations for the tangent line to the curve. Then | {
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"url": "http://nvaw.toysgarage.it/parametric-surface-grapher.html"
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• In the practice session after this video, I had this problem to solve.
b^4 * b^1/4=? I added the powers of 4 and 1/4 to get 17/4, because 4/1=16/4 I added to get 17/4. I ended up getting that wrong, so I looked at the hints and its 15/4 why?
(1 vote)
• Your math is correct, so either the answer is wrong or there is a negative sign in front of the 1/4 which would then be 16/4 - 1/4 = 15/4.
• how do you type the answer in the practice?
• why are all the formulas a+b or a-b?
(1 vote)
• Exponents are shortcuts for multiplication, so x^3 = x*x*x. If you multiply x^3*x^2, you have x*x*x * x*x = x^5, thus the exponents were added 3 + 2 = 5.
If you are dividing x^5/x^2, you have (x*x*x*x*x)/(x*x), and x/x = 1 because anything except 0 divided by itself is 1. Two of the xs cancel out, so you have x*x*x left = x^3. Subtracting 5-2 = 3. So exponents add when you multiply same bases and subtract when you divide same bases. | {
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} |
quantum-gate, bloch-sphere
// Prefer axes that point positive-ward.
if (x + y + z < 0) {
x = -x;
y = -y;
z = -z;
θ = -θ;
}
return {axis: [x, y, z], angle: θ, phase: φ.phase()};
} | {
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"lm_q1q2_score": null,
"lm_q2_score": null,
"openwebmath_perplexity": null,
"openwebmath_score": null,
"tags": "quantum-gate, bloch-sphere",
"url": null
} |
catkin, ros-groovy
Title: Error building catkin on Pandaboard ES (Groovy)
Hi, I'm fairly new to Linux and ROS. I'm trying to install Groovy onto my Pandaboard ES running Ubuntu 12.04. Upon building the catkin packages I get the following errors. I have followed both of the instructions in the links below with no success yet .
Thanks in advance!
<== Finished processing package [89 of 147]: 'sensor_msgs'
==> Processing catkin package: 'camera_calibration_parsers'
==> Building with env: '/opt/ros/groovy/env.sh'
Makefile exists, skipping explicit cmake invocation...
==> make cmake_check_build_system in '/opt/ros/groovy/ros_catkin_ws/build_isolated/camera_calibration_parsers'
==> make -j2 -l2 in '/opt/ros/groovy/ros_catkin_ws/build_isolated/camera_calibration_parsers'
[ 25%] Building CXX object CMakeFiles/camera_calibration_parsers.dir/src/parse_yml.cpp.o | {
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"tags": "catkin, ros-groovy",
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{2}.The absolute minimum is \answer {-1/(2e)} and it occurs at x = \answer {-1/2}. Suppose that the values of the buyer for nitems are independent and supported on some interval [u min;ru min] for some u min>0 and r 1. Built at The Ohio State UniversityOSU with support from NSF Grant DUE-1245433, the Shuttleworth Foundation, the Department of Mathematics, and the Affordable Learning ExchangeALX. The next theorem is called Rolle’s Theorem and it guarantees the existence of an extreme value on the interior of a closed interval, under certain conditions. We learn to compute the derivative of an implicit function. If f'(c) is defined, then Derivatives of sums, products and composites 13. If a function $$f\left( x \right)$$ is continuous on a closed interval $$\left[ {a,b} \right],$$ then it attains the least upper and greatest lower bounds on this interval. three step process. This is used to show thing like: There is a way to set the price of an item so as to maximize profits. Solution: | {
"domain": "zafarindustries.com",
"id": null,
"lm_label": "1. YES\n2. YES\n\n",
"lm_name": "Qwen/Qwen-72B",
"lm_q1_score": 0.9852713878802045,
"lm_q1q2_score": 0.8374522742816736,
"lm_q2_score": 0.8499711699569786,
"openwebmath_perplexity": 221.00805278696637,
"openwebmath_score": 0.8135552406311035,
"tags": null,
"url": "http://zafarindustries.com/where-was-jmegb/618c52-extreme-value-theorem-open-interval"
} |
c#, parsing
public HtmlNode GetNode(string page, string xPath)
{
int index = Documents.Add(new HtmlDocument());
((HtmlDocument)Documents[index]).LoadHtml(page);
return ((HtmlDocument) Documents[index]).DocumentNode.SelectSingleNode(xPath);
}
public HtmlNodeCollection GetNodes(string page, string xPath)
{
int index = Documents.Add(new HtmlDocument());
((HtmlDocument)Documents[index]).LoadHtml(page);
return ((HtmlDocument)Documents[index]).DocumentNode.SelectNodes(xPath);
}
public void Dispose()
{
if (null != Documents)
Documents.Clear();
Documents = null;
GC.Collect();
}
}
public enum ParseType
{
InnerHtml,
OuterHtml,
InnerText,
Attribute
} There are a few things I've noticed. | {
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"tags": "c#, parsing",
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Similar questions to practice:
if-n-is-the-greatest-positive-integer-for-which-2n-is-a-fact-144694.html
what-is-the-largest-power-of-3-contained-in-103525.html
if-n-is-the-product-of-all-positive-integers-less-than-103218.html
if-n-is-the-product-of-integers-from-1-to-20-inclusive-106289.html
if-n-is-the-product-of-all-multiples-of-3-between-1-and-101187.html
if-p-is-the-product-of-integers-from-1-to-30-inclusive-137721.html
what-is-the-greatest-value-of-m-such-that-4-m-is-a-factor-of-105746.html
if-6-y-is-a-factor-of-10-2-what-is-the-greatest-possible-129353.html
if-m-is-the-product-of-all-integers-from-1-to-40-inclusive-108971.html
if-p-is-a-natural-number-and-p-ends-with-y-trailing-zeros-108251.html
if-73-has-16-zeroes-at-the-end-how-many-zeroes-will-147353.html
find-the-number-of-trailing-zeros-in-the-expansion-of-108249.html
how-many-zeros-are-the-end-of-142479.html
how-many-zeros-does-100-end-with-100599.html
find-the-number-of-trailing-zeros-in-the-product-of-108248.html | {
"domain": "gmatclub.com",
"id": null,
"lm_label": "1. Yes\n2. Yes\n",
"lm_name": "Qwen/Qwen-72B",
"lm_q1_score": 0.9511422213778251,
"lm_q1q2_score": 0.8642248513448179,
"lm_q2_score": 0.9086179037377831,
"openwebmath_perplexity": 1646.7932991234186,
"openwebmath_score": 0.8042828440666199,
"tags": null,
"url": "https://gmatclub.com/forum/how-many-zeros-does-100-end-with-100599.html?sort_by_oldest=true"
} |
bash
A cross-platform way is to use tilde expansion, though the eval could be dangerous if the input is untrustworthy:
histfile=$(eval echo "~${1-root}")/.bash_history
The isRoot check should be done on the username (or UID) instead of the home directory. It feels very unconventional to assign a boolean variable in Bash. Keep in mind that the convention is that zero statuses are considered "true" and non-zero statuses are considered "false". I'd advise you not to write that statement at all, but can't really advise you what to do instead since you haven't shown us what you intend to do with that variable. | {
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"openwebmath_score": null,
"tags": "bash",
"url": null
} |
Let $u$ be an eigenvector: $u\ne0$ and $Mu=\lambda u$. Then, writing $$u=\begin{bmatrix}v\\w\end{bmatrix}$$ with $v$ and $w$ being $n\times 1$ column vectors, we have $$\begin{bmatrix}A & B \\ C & -A^T\end{bmatrix} \begin{bmatrix}v\\w\end{bmatrix}= \begin{bmatrix}Av+Bw\\Cv-A^Tw\end{bmatrix}= \begin{bmatrix}\lambda v\\\lambda w\end{bmatrix}$$ Now consider $$u'=\begin{bmatrix}w\\-v\end{bmatrix}$$ so $$M^Tu'= \begin{bmatrix} A^T & C \\ B & -A\end{bmatrix} \begin{bmatrix}w\\-v\end{bmatrix} = \begin{bmatrix} A^Tw-Cv \\ Bw+Av \end{bmatrix} =\begin{bmatrix} -\lambda w \\ \lambda v \end{bmatrix}= -\lambda u'$$ A matrix and its transpose have the same eigenvalues. | {
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"id": null,
"lm_label": "1. YES\n2. YES",
"lm_name": "Qwen/Qwen-72B",
"lm_q1_score": 0.9820137931962462,
"lm_q1q2_score": 0.8118423805827445,
"lm_q2_score": 0.8267117898012105,
"openwebmath_perplexity": 86.97058384903039,
"openwebmath_score": 0.9454951882362366,
"tags": null,
"url": "https://math.stackexchange.com/questions/2102240/proof-concerning-eigenvalues"
} |
Acts 1:14 one-to-one ) that pass both the vertical line tells. / Office365 at work understand what the differnce is between a vertical and line. Drawn through the function f is bijective if and only if any horizontal test... Every x-value of a relation is a question and answer site for people studying math any... Is when you draw a horizontal line will intersect the graph more than once, then that graph a! Test means, you can see if a relation is a line parallel the. Great answers circle fails the horizontal line horizontal line test vs vertical line test supports the definition of a,! It does not function at all on the relation 8 back them with. Showing how to determine if it passes both the vertical line test easy way to tell you if have. Answer ”, you draw a horizontal line cuts the curve does n't have an horizontal line test vs vertical line test! Legally refuse to follow a legal, but unethical order read the function does have two or more points it! Function or not a function must | {
"domain": "com.br",
"id": null,
"lm_label": "1. YES\n2. YES",
"lm_name": "Qwen/Qwen-72B",
"lm_q1_score": 0.9683812327313545,
"lm_q1q2_score": 0.8111354585410767,
"lm_q2_score": 0.8376199694135332,
"openwebmath_perplexity": 511.1752047267459,
"openwebmath_score": 0.2904495894908905,
"tags": null,
"url": "http://www.multiplagp.com.br/gyp1aj/horizontal-line-test-vs-vertical-line-test-7fa0c0"
} |
ros, network
All considered, I think "happy-go-lucky" is the better choice these days, so Cyclone DDS's default will likely change. | {
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"openwebmath_score": null,
"tags": "ros, network",
"url": null
} |
java, swing, layout
public int nextTextBox = 10;
JTextField[] allField = new JTextField [20];
public void runGUI()
{
myMainWindow.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
myMainWindow.setLayout(new GridLayout(1,1));
createSortTestPanel();
MyMenuBar mbr = new MyMenuBar(this);
myMainWindow.setJMenuBar(mbr);
myMainWindow.getContentPane().add(sortPanel);
myMainWindow.setVisible(true);
myMainWindow.pack();
myMainWindow.setMinimumSize(new Dimension(myMainWindow.getBounds().getSize()));
}
public void createSortTestPanel()
{
MigLayout layout = new MigLayout("" , "[grow]");
sortPanel.setLayout(layout);
refreshScreen();
}
public void refreshScreen()
{
sortPanel.removeAll(); | {
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"lm_name": null,
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"lm_q1q2_score": null,
"lm_q2_score": null,
"openwebmath_perplexity": null,
"openwebmath_score": null,
"tags": "java, swing, layout",
"url": null
} |
optics, geometric-optics
(note: I'll probably add on to this answer a couple times, because I don't have time to give a good and thorough summary right now. If you want a really thorough description, check out the thesis I linked above. It may be a little over your head if you don't have background in optics though, which is what my summary here should help with.)
Hardware
This technique depends on some very clever data processing techniques, and on the unusual type of camera (Ren Ng calls it "plenoptic" which isn't a term I've heard before) that is used to capture the data.
This camera has an array of very small lenses (a "microlenslet array") at its image plane, where a normal camera would just have the image sensor. The image sensor is positioned slightly behind this. | {
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"openwebmath_perplexity": null,
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"tags": "optics, geometric-optics",
"url": null
} |
program converting radians/degrees into minutes, seconds, and to radians/degrees. 01745329252 radians: 1° = π/180° = 0. Conversion of units of measurement from physics and maths, e. You can also check the seconds to radians conversion chart below, or go back to seconds to radians converter to top. The equation used to convert degrees to radians is rad = (deg x pi)/180, where rad stands for radians, deg is degrees and pi is equal to 3. So, first convert your 'd. 1 rad = 180°/π One degree is equal to 60 minutes and equal to 3600 seconds: 1° = 60' = 3600" The decimal degrees dd is equal to: dd = d + m/60 + s/3600. 81 seconds of arc angle ( arcsecond ). You can remove the degree sign since your answer will be in radians anyway. SQL HOME SQL Intro SQL Syntax SQL Select SQL Select Distinct SQL Where SQL And, Or, Not SQL Order By SQL Insert Into SQL Null Values SQL Update SQL Delete SQL Select Top SQL Min and Max SQL Count, Avg, Sum SQL Like SQL Wildcards SQL In SQL Between SQL Aliases SQL | {
"domain": "mpl-bauen.de",
"id": null,
"lm_label": "1. YES\n2. YES\n\n",
"lm_name": "Qwen/Qwen-72B",
"lm_q1_score": 0.9732407168145568,
"lm_q1q2_score": 0.8089022495670698,
"lm_q2_score": 0.8311430415844384,
"openwebmath_perplexity": 1363.7600780839207,
"openwebmath_score": 0.6850907206535339,
"tags": null,
"url": "http://rhzc.mpl-bauen.de/how-to-convert-seconds-into-radians.html"
} |
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