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short answer as far as i know, a complete neural map ( a connectome ) is only available for the roundworm c. elegens, a nematode with only 302 neurons ( fig. 1 ). fig. 1. c. elegans ( left, size : ~ 1 mm ) and connectome of c. elegans ( right ). sources : utrecht university & farber ( 2012 ) background looking at the l... | https://api.stackexchange.com |
every simple closed curve that you can draw by hand will pass through the corners of some square. the question was asked by toeplitz in 1911, and has only been partially answered in 1989 by stromquist. as of now, the answer is only known to be positive, for the curves that can be drawn by hand. ( i. e. the curves that ... | https://api.stackexchange.com |
a question that requires quite a lot of guts to ask on this site : ) nonetheless, and risking sparking a debate, there are a few arguments that spring to ( my! ) mind that can support the notion that we thrive better in'day mode'( i. e., photopic conditions ). to start with a controversial assumption, humans are diurna... | https://api.stackexchange.com |
why does a light object appear lighter in your peripheral vision when it's dark? | https://api.stackexchange.com |
when you add salt to an ice cube, you end up with an ice cube whose temperature is above its melting point. this ice cube will do what any ice cube above its melting point will do : it will melt. as it melts, it cools down, since energy is being used to break bonds in the solid state. ( note that the above point can be... | https://api.stackexchange.com |
your image doesn't have uniform brightness, so you shouldn't work with a uniform threshold. you need an adaptive threshold. this can be implemented by preprocessing the image to make the brightness more uniform across the image ( code written in mathematica, you'll have to implement the matlab version for yourself ) : ... | https://api.stackexchange.com |
your understanding is correct. if you sample at rate $ f _ s $, then with real samples only, you can unambiguously represent frequency content in the region $ [ 0, \ frac { f _ s } { 2 } ) $ ( although the caveat that allows bandpass sampling still applies ). no additional information can be held in the other half of t... | https://api.stackexchange.com |
let's talk about the balloon first because it provides a pretty good model for the expanding universe. it's true that if you draw a big circle then it will quickly expand as you blow into the balloon. actually, the apparent speed with which two of the points on the circle in a distance $ d $ of each other would move re... | https://api.stackexchange.com |
until someone identifies an β update β function in pymol, i think the next best thing is to use scripting. ( see the pymol wiki ) it is an imperfect solution, but it may work for the situation presented in the original post if the session may be reproduced. to begin capturing the commands in pymol, including menu selec... | https://api.stackexchange.com |
you get burned because energy is transferred from the hot object to your hand until they are both at the same temperature. the more energy transferred, the more damage done to you. aluminium, like most metals, has a lower heat capacity than water ( ie you ) so transferring a small amount of energy lowers the temperatur... | https://api.stackexchange.com |
biological examples similar to programming statements : if : transcriptional activator ; when present a gene will be transcribed. in general there is no termination of events unless the signal is gone ; the program ends only with the death of the cell. so the if statement is always a part of a loop. while : transcripti... | https://api.stackexchange.com |
variable? " | https://api.stackexchange.com |
i agree completely with srikant's explanation. to give a more heuristic spin on it : classical approaches generally posit that the world is one way ( e. g., a parameter has one particular true value ), and try to conduct experiments whose resulting conclusion - - no matter the true value of the parameter - - will be co... | https://api.stackexchange.com |
. your rule allows 5 out of the 100 to be complete nonsense [ negative values, impossible values ] as long as the other 95 are correct ; that's ridiculous. " a frequentist die - hard might criticize the bayesian credibility interval like this : " so what if 95 % of the posterior probability is included in this range? w... | https://api.stackexchange.com |
my new cookie jar. i'd pull one single cookie at random from the jar, count the chips on the cookie, and try to express my uncertainty - - at the 70 % level - - of which jars it could be. thus it's the identity of the jar ( a, b, c or d ) that is the value of the parameter being estimated. the number of chips ( 0, 1, 2... | https://api.stackexchange.com |
and let's assume that the deliverman chooses among them uniformly - - meaning he has all four on his truck, and when he gets to our house he picks one at random, each with uniform probability. " " with that assumption, now let's look at the joint probabilities of the whole event - - the jar type and the number of chips... | https://api.stackexchange.com |
draw a cookie with zero chips! you just say it's the empty interval. but that's obviously wrong - - it has to be one of the four types of jars. how can you live with yourself, stating an interval at the end of the day when you know the interval is wrong? and ditto when you pull a cookie with 3 chips - - your interval i... | https://api.stackexchange.com |
no jar will result in a wrong answer more than 30 % of the time. " " the column sums matter, " i said. " the row sums matter, " bayesia said. " i can see we're at an impasse, " i said. " we're both correct in the mathematical statements we're making, but we disagree about the appropriate way to quantify uncertainty. " ... | https://api.stackexchange.com |
yes, this helps as well with other infectious diseases. a good example is the flu, which season was measurably shorter this year than in other years on record. see the figure from the reference 1 for comparision : reference 2 shows that this is also true for other respiratory diseases ( figure 2 ) : this shows very wel... | https://api.stackexchange.com |
to follow up what mbq said, there have been a number of " origin of life " studies which suggest that rna was a precursor to dna, the so - called " rna world " ( 1 ). since rna can carry out both roles which dna and proteins perform today. further speculations suggest things like a peptide - nucleic acids " pna " may h... | https://api.stackexchange.com |
storing local variables on a stack is an implementation detail β basically an optimization. you can think of it this way. when entering a function, space for all local variables is allocated somewhere. you can then access all variables, since you know their location somehow ( this is part of the process of allocation )... | https://api.stackexchange.com |
there is a wide variety of algorithms ; barnes hut is a popular $ \ mathcal { o } ( n \ log n ) $ method, and the fast multipole method is a much more sophisticated $ \ mathcal { o } ( n ) $ alternative. both methods make use of a tree data structure where nodes essentially only interact with their nearest neighbors at... | https://api.stackexchange.com |
the color burst is also an indicator that there is a color signal. this is for compatibility with black and white signals. no color burst means b & w signal, so only decode the luminance signal ( no croma ). no signal, no color burst, so the decoder falls back to b & w mode. same idea goes to fm stereo / mono. if there... | https://api.stackexchange.com |
this is to expand on leon's suggestion to use a hub. the usb hubs are not all created equal. unofficially, there are several " grades " : cheap hubs. these are cost optimized to the point where they don't adhere to the usb spec any more. often, the + 5v lines of the downstream ports are wired directly to the computer. ... | https://api.stackexchange.com |
unlike the conventional wisdom, the pain you feel the next day ( after a strenuous exercise ) has nothing to do with lactic acid. actually, lactic acid is rapidly removed from the muscle cell and converted to other substances in the liver ( see cori cycle ). if you start to feel your muscles " burning " during exercise... | https://api.stackexchange.com |
to get out of the bed the next day. edit : this comment asks if there is evidence of the " micro tear model " or " damage model " ( also eimd, or exercise - induced muscle damage ). first, that's precisely why i was careful when i used the term hypothesis. second, despite the matter not being settled, there is indeed e... | https://api.stackexchange.com |
unfortunately the other 3 answers to the question are incorrect, but helps keeping a common misunderstanding alive : - ) thieving is added to the outer layers in order to help a more balanced chemical process for the plating. also notice that there is no need to " balance copper " ( or stackups for that matter ) in mod... | https://api.stackexchange.com |
zeroing bins in the frequency domain is the same as multiplying by a rectangular window in the frequency domain. multiplying by a window in the frequency domain is the same as circular convolution by the transform of that window in the time domain. the transform of a rectangular window is the sinc function ( $ \ sin ( ... | https://api.stackexchange.com |
this is the xkcd nerd sniping problem. it forced me to abandon everything else i was doing to research and write up this answer. then, years later, it compelled me to return and edit it for clarity. the following full solution is based on the links posted in the other answer. but in addition to presenting this informat... | https://api.stackexchange.com |
\ tag { 1 } \ label { eqv } $ $ ( $ \ delta _ \ vec { n } $ equals $ 1 $ if $ \ vec { n } = \ vec { 0 } $ and $ 0 $ otherwise. ) solving this equation for $ v _ \ vec { n } $ will give us our answer. indeed, the resistance between $ \ vec { 0 } $ and $ \ vec { a } $ will simply be $ $ r _ \ vec { a } = v _ \ vec { 0 } ... | https://api.stackexchange.com |
vec { k } ) $. then noting that the two sides of $ \ eqref { eqg } $ can be written as \ begin { align } \ sum _ { i, \ pm } ( g _ { \ vec { n } \ pm \ vec { e } _ i } - g _ \ vec { n } ) & = \ int _ 0 ^ { 2 \ pi } \ frac { d ^ n \ vec { k } } { ( 2 \ pi ) ^ n } e ^ { i \ vec { k } \ cdot \ vec { n } } \ left ( \ sum _... | https://api.stackexchange.com |
} = v _ \ vec { 0 } - v _ \ vec { a } = 2 ( g _ \ vec { a } - g _ \ vec { 0 } ) = \ int _ 0 ^ { 2 \ pi } \ frac { d ^ n \ vec { k } } { ( 2 \ pi ) ^ n } \ frac { 1 - \ cos ( \ vec { k } \ cdot \ vec { a } ) } { n - \ sum _ i \ cos ( k _ i ) } $ $ why is this the right answer? ( from this point on, $ n = 2 $. ) i said e... | https://api.stackexchange.com |
{ 1 - \ cos ( n ( x + y ) ) } { 2 - \ cos ( x ) - \ cos ( y ) } \ \ & = \ frac { 1 } { 2 ( 2 \ pi ) ^ 2 } \ int _ a dx \, dy \, \ frac { 1 - \ cos ( n ( x + y ) ) } { 1 - \ cos ( \ frac { x + y } { 2 } ) \ cos ( \ frac { x - y } { 2 } ) } \ end { align } where $ a $ is the square $ 0 \ leq x, y \ leq 2 \ pi $. because ... | https://api.stackexchange.com |
, n } & = \ frac { 2 } { \ pi } \ left ( 1 + \ frac { 1 } { 3 } + \ dots + \ frac { 1 } { 2n - 1 } \ right ) \ end { align } a recurrence relation the remaining resistances can in fact be determined without doing any more integrals! all we need is rotational / reflectional symmetry, $ $ r _ { n, m } = r _ { \ pm n, \ p... | https://api.stackexchange.com |
in python : import numpy as np import fractions as fr n = 4 arr = np. empty ( ( n * 2 + 1, n * 2 + 1, 2 ), dtype ='object') def plus ( i, j ) : arr [ i + 1, j ] = 4 * arr [ i, j ] - arr [ i - 1, j ] - arr [ i, j + 1 ] - arr [ i, abs ( j - 1 ) ] def even ( i ) : arr [ i, i ] = arr [ i - 1, i - 1 ] + [ 0, fr. fraction ( ... | https://api.stackexchange.com |
\ frac { 1 } { 2 } + \ frac { 4 } { 3 \ pi } & \ frac { 46 } { 15 \ pi } & \ frac { 24 } { 5 \ pi } - \ frac { 1 } { 2 } \ \ \ hdashline 2 - \ frac { 4 } { \ pi } & \ frac { 4 } { \ pi } - \ frac { 1 } { 2 } & \ frac { 8 } { 3 \ pi } & \ frac { 1 } { 2 } + \ frac { 4 } { 3 \ pi } & 6 - \ frac { 236 } { 15 \ pi } \ \ \ ... | https://api.stackexchange.com |
in 1933, kurt godel showed that the class called $ \ lbrack \ exists ^ * \ forall ^ 2 \ exists ^ *, { \ mathrm { all } }, ( 0 ) \ rbrack $ was decidable. these are the formulas that begin with $ \ exists a \ exists b \ ldots \ exists m \ forall n \ forall p \ exists q \ ldots \ exists z $, with exactly two $ \ forall $... | https://api.stackexchange.com |
the shortest answer : never, unless you are sure that your linear approximation of the data generating process ( linear regression model ) either by some theoretical or any other reasons is forced to go through the origin. if not the other regression parameters will be biased even if intercept is statistically insignif... | https://api.stackexchange.com |
there are a few good answers to this question, depending on the audience. i've used all of these on occasion. a way to solve polynomials we came up with equations like $ x - 5 = 0 $, what is $ x $?, and the naturals solved them ( easily ). then we asked, " wait, what about $ x + 5 = 0 $? " so we invented negative numbe... | https://api.stackexchange.com |
the equations since there is no such thing. then, one mathematician decided to just " roll with it ", and kept working, and found out that all those square roots cancelled each other out. amazingly, the answer that was left was the correct answer ( he was working on finding roots of polynomials, i think ). which lead h... | https://api.stackexchange.com |
abbreviations auc = area under the curve. auroc = area under the receiver operating characteristic curve. auc is used most of the time to mean auroc, which is a bad practice since as marc claesen pointed out auc is ambiguous ( could be any curve ) while auroc is not. interpreting the auroc the auroc has several equival... | https://api.stackexchange.com |
compute two metrics from the confusion matrix, which we will later combine into one : true positive rate ( tpr ), aka. sensitivity, hit rate, and recall, which is defined as $ \ frac { tp } { tp + fn } $. intuitively this metric corresponds to the proportion of positive data points that are correctly considered as posi... | https://api.stackexchange.com |
citing bellanger's classic digital processing of signals β theory and practice, the point is not where your cut - off frequency is, but how much attenuation you need, how much ripple in the signal you want to preserve you can tolerate and, most importantly, how narrow your transition from pass - to stopband ( transitio... | https://api.stackexchange.com |
$ \ delta _ 1 = 10 ^ { - 4 } $. so, plugging this in : $ $ \ begin { align } n _ \ text { tommy's filter } & \ approx \ frac 23 \ log _ { 10 } \ left [ \ frac1 { 10 \ delta _ 1 \ delta _ 2 } \ right ] \, \ frac { f _ s } { \ delta f } \ \ & = \ frac 23 \ log _ { 10 } \ left [ \ frac1 { 10 \ cdot 10 ^ { - 4 } \ cdot10 ^... | https://api.stackexchange.com |
lots of aliasing, but since you're eradicating all signal that could alias, you can savely do so. clever filter implementations ( polyphase decimators ) can reduce the computational effort by m, this way. in your case, you could easily decimate by $ m = 50 $, and then, your computer would only have to calculate $ \ fra... | https://api.stackexchange.com |
##pliers ( typically, " dsp slices " ) run at a lower rate, and hence, multiplex them ( number of dsp slices is usually very limited ), using one multiplier for multiple taps. yet another reason is that especially half - band filters, i. e. lowpasses that suppress half the input band and deliver half the input rate, ar... | https://api.stackexchange.com |
great question! when i was teaching, anslyn and dougherty was a decent text for this. here are some general comments : first, please note that you cannot be sure about a mechanism. that's the real killer. you can devise experiments that are consistent with the mechanism but because you cannot devise and run all possibl... | https://api.stackexchange.com |
t. a. ing for greg fu, he really liked to use an example with the von richter reaction. i might be able to find those references... | https://api.stackexchange.com |
the main thing is presumably that $ aa ^ t $ is symmetric. indeed $ ( aa ^ t ) ^ t = ( a ^ t ) ^ ta ^ t = aa ^ t $. for symmetric matrices one has the spectral theorem which says that we have a basis of eigenvectors and every eigenvalue is real. moreover if $ a $ is invertible, then $ aa ^ t $ is also positive definite... | https://api.stackexchange.com |
short answer : yes, but you need to get permission ( and modified software ) from ont before doing that.... but that doesn't tell the whole story. this question has the potential to be very confusing, and that's through no fault of the questioner. the issue is that for the minion, sequencing ( or more specifically, gen... | https://api.stackexchange.com |
that all useful albacore changes will eventually propagate through to nanonet. there is another non - ont basecaller that i'm aware of which uses a neural network for basecalling : deepnano. other basecallers exist, each varying distances away technology - wise, and i expect that more will appear in the future as the t... | https://api.stackexchange.com |
in the early 90s we were looking for a method to solve the tdse fast enough to do animations in real time on a pc and came across a surprisingly simple, stable, explicit method described by pb visscher in computers in physics : " a fast explicit algorithm for the time - dependent schrodinger equation ". visscher notes ... | https://api.stackexchange.com |
1 } { 2 } \ delta t ) r ( x, t - \ frac { 1 } { 2 } \ delta t ) + i ^ 2 ( x, t ) $ $ at half - integer time steps makes the algorithm unitary, thus conserving probability. with enough code optimization, we were able to get very nice animations computed in real - time on 80486 machines. students could " draw " any poten... | https://api.stackexchange.com |
get someone to relax their neck as much as possible, stabilize their torso, then punch them in the head with a calibrated fist and measure the initial acceleration. apply $ \ vec f = m \ vec a $. | https://api.stackexchange.com |
i haven't quite got this straight yet, but i think one way to go is to think about choosing points at random from the positive reals. this answer is going to be rather longer than it really needs to be, because i'm thinking about this in a few ( closely related ) ways, which probably aren't all necessary, and you can d... | https://api.stackexchange.com |
poor ). this is just makes rigorous the idea of randomly choosing unordered sets of points from a sigma - finite measure space $ ( e, \ mathcal { e }, \ mu ) $. technically, it can be defined as a set of nonnegative integer - valued random variables $ \ { n ( a ) \ colon a \ in \ mathcal { e } \ } $ counting the number... | https://api.stackexchange.com |
so that each one only has probability $ \ mu ( a ) / n $ of hitting the set, and is distributed according to the probability distribution $ \ mu / \ mu ( a ) $. this is consistent, at least, if you think about the probability of hitting a subset $ b \ subseteq a $. the probability of missing with all of them is $ ( 1 -... | https://api.stackexchange.com |
$ t _ { n + 1 } $ is the sum of $ n + 1 $ iid random variables of mean one, the law of large numbers suggests that it should be peaked approximately around $ n $. the central limit theorem goes further, and gives $ \ dfrac { t ^ n } { n! } e ^ { - t } \ approx \ dfrac { 1 } { \ sqrt { 2 \ pi n } } e ^ { - ( t - n ) ^ 2... | https://api.stackexchange.com |
i think the best method or combination of methods will depend on aspects of the data that might vary from one dataset to another. e. g. the type, size, and frequency of structural variants, the number snvs, the quality of the reference, contaminants or other issues ( e. g. read quality, sequencing errors ) etc. for tha... | https://api.stackexchange.com |
first of all, it depends on how the tap water was treated before it was piped to your house. in most cases, the water was chlorinated to remove microorganisms. by the time the water arrives at your house, there is very little ( if any ) chlorine left in the water. when you fill you container, there is likely to be some... | https://api.stackexchange.com |
the frequency resolution is dependent on the relationship between the fft length and the sampling rate of the input signal. if we collect 8192 samples for the fft then we will have : $ $ \ frac { 8192 \ \ text { samples } } { 2 } = 4096 \ \, \ text { fft bins } $ $ if our sampling rate is 10 khz, then the nyquist - sha... | https://api.stackexchange.com |
is to reduce the sampling rate, which is the second way to increase frequency resolution. in your example, if you drop your sampling rate to something like 4096 hz, then you only need a 4096 point fft to achieve 1 hz bins and can still resolve a 2 khz signal. this reduces the fft bin size, but also reduces the bandwidt... | https://api.stackexchange.com |
the obvious answer is that different people wrote them. it's fairly common in bioinformatics for people with a computer science background to get frustrated with existing tools and create their own alternative tool ( rather than improving an existing tool ). over time, tools with similar initial aims will have popular ... | https://api.stackexchange.com |
the choice of $ k = 10 $ is somewhat arbitrary. here's how i decide $ k $ : first of all, in order to lower the variance of the cv result, you can and should repeat / iterate the cv with new random splits. this makes the argument of high $ k $ = > more computation time largely irrelevant, as you anyways want to calcula... | https://api.stackexchange.com |
the following are both plausible messages, but have a completely different meaning : sos help =... - - -......... -... - -. = >... - - -......... -... - -. i am his date =... - - -......... -... - -. = >... - - -......... -... - -. | https://api.stackexchange.com |
the hydrochloric acid in the stomach is already quite dilute ; its ph is in fact no less than 1. 5 so that at the extreme maximum there is only 0. 03 molar hydrochloric acid. and even that small amount is, of course, stabilized by being dissociated into solvated ions. there is just not enough stuff to react violently. | https://api.stackexchange.com |
" computational scientist " is somewhat broad because it includes people who doing numerical analysis with paper / latex and proof - of - concept implementations, people writing general purpose libraries, and people developing applications that solve certain classes of problems, and end users that utilize those applica... | https://api.stackexchange.com |
with compiled code, a working knowledge of compilers, linkers, and build tools like make will save a lot of time. version control is essential for everyone, even if you work alone. learn git or mercurial and use it for every project. if you develop libraries, you should know the language standards reasonably completely... | https://api.stackexchange.com |
it is very hard to define a human mind with a such mathematical rigor as it is possible to define a turing machine. we still do not have a working model of a mouse brain however we have the hardware capable of simulating it. a mouse has around 4 million neurons in the cerebral cortex. a human being has 80 - 120 billion... | https://api.stackexchange.com |
as far as i know, lapack is the only publicly available implementation of a number of algorithms ( nonsymmetric dense eigensolver, pseudo - quadratic time symmetric eigensolver, fast jacobi svd ). most libraries that don't rely on blas + lapack tend to support very primitive operations like matrix multiplication, lu fa... | https://api.stackexchange.com |
firstly, it's not true that you can't tell racial background from dna. you most certainly can ; it's quite possible to give fairly accurate phenotypic reconstruction of the features we choose as racial markers from dna samples alone and also possible to identify real geographic ancestral populations from suitable marke... | https://api.stackexchange.com |
short answer : in my opinion, my approach would be to pull out the cds exons and run bedtools on those. a few more details : when you pull out the exons, make sure that you assign them all ids if the don't already have them assigned and record which ids " belong " to which genes. now when you get exons that overlap, yo... | https://api.stackexchange.com |
corrosion resistant products, ltd., with the help of dupont, has established this source of information on what can and cannot eat teflon. here's a list : sodium and potassium metal - these reduce and defluorinate ptfe, which finds use in etching ptfe finely divided metal powders, like aluminum and and magnesium, cause... | https://api.stackexchange.com |
two examples of libraries that use modern c + + constructs : both the eigen and armadillo libraries ( linear algebra ) use several modern c + + constructs. for instance, they use both expression templates to simplify arithmetic expressions and can sometimes eliminate some temporaries : ( presentation on expression temp... | https://api.stackexchange.com |
the effective length is $ \ tilde { l } _ i = l _ i - \ mu + 1 $ ( note the r code at the bottom of harold's blog post ), which in the case of $ \ mu < l _ i $ should be 1. ideally, you'd use the mean fragment length mapped to the particular feature, rather than a global $ \ mu $, but that's a lot more work for likely ... | https://api.stackexchange.com |
that's a good, concise statement of bent's rule. of course we could have just as correctly said that p character tends to concentrate in orbitals directed at electronegative elements. we'll use this latter phrasing when we examine methyl fluoride below. but first, let's expand on the definition a bit so that it is clea... | https://api.stackexchange.com |
expect more p character in the carbon hybrid orbital used to form the $ \ ce { c - f } $ bond, and more s - character in the carbon hybrid orbitals used to form the $ \ ce { c - h } $ bonds. the physically observable result of all this is that we would expect an $ \ ce { h - c - h } $ angle larger than the tetrahedral ... | https://api.stackexchange.com |
an article by snell and pleasanton,'the atomic and molecular consequenses of radioactive decay ', ( j. phys. chem., 62 ( 11 ), pp 1377 β 1382, $ 1958 $ ) supports ben norris's comment. it is clear... that $ \ ce { ^ { 14 } co2 } $ remains predominantly bound as $ \ ce { no2 + } $, a result that is perhaps not surprisin... | https://api.stackexchange.com |
pedro f. felzenszwalb and daniel p. huttenlocher have published their implementation for the distance transform [ archive ]. you cannot use it for volumetric images, but maybe you can extend it to support 3d data. i have only used it as a black box. | https://api.stackexchange.com |
imagine a big family dinner where everybody starts asking you about pca. first, you explain it to your great - grandmother ; then to your grandmother ; then to your mother ; then to your spouse ; finally, to your daughter ( a mathematician ). each time the next person is less of a layman. here is how the conversation m... | https://api.stackexchange.com |
across wines as possible. the second answer is that you look for the properties that would allow you to predict, or " reconstruct ", the original wine characteristics. again, imagine that you come up with a property that has no relation to the original characteristics - like the shape of a wine bottle ; if you use only... | https://api.stackexchange.com |
time, you will notice that " the maximum variance " and " the minimum error " are reached at the same time, namely when the line points to the magenta ticks i marked on both sides of the wine cloud. this line corresponds to the new wine property that will be constructed by pca. by the way, pca stands for " principal co... | https://api.stackexchange.com |
of the $ x $ variable is $ 1. 07 $, the variance of the $ y $ variable is $ 0. 64 $, and the covariance between them is $ 0. 63 $. as it is a square symmetric matrix, it can be diagonalized by choosing a new orthogonal coordinate system, given by its eigenvectors ( incidentally, this is called spectral theorem ) ; corr... | https://api.stackexchange.com |
the idea of the algorithm is this : assume you have a length $ n $ signal that is sparse in the frequency domain. this means that if you were to calculate its discrete fourier transform, there would be a small number of outputs $ k \ ll n $ that are nonzero ; the other $ n - k $ are negligible. one way of getting at th... | https://api.stackexchange.com |
an algorithm that exploited that property. that level of sparsity doesn't seem to square with the application space for this particular algorithm, so it may just be an illustrative example. i need to read through the literature a bit more to get a better feel for how practical such a technique is for use on real - worl... | https://api.stackexchange.com |
short answer the concept of species is poorly defined and is often misleading. the concepts of lineage and clade / monophyletic group are much more helpful. imo, the only usefulness of this poorly defined concept that is the " species " is to have a common vocabulary for naming lineages. note that homo neanderthalis is... | https://api.stackexchange.com |
concept and just use the term lineage and use an accurate description of the reproductive barriers or genetic / functional divergence between lineage rather than using this made - up word that is " species ". i will below discuss the most commonly used definition ( the one you cite ) that is called the biological speci... | https://api.stackexchange.com |
##erus ( let's assume we are talking about mammals ) but can develop in some other environment and then become a healthy adult? ring species in space as you said in your question, ring species is another good example as to why the concept of species is not very helpful ( see the post transitivity of species definitions... | https://api.stackexchange.com |
but they still meet to reproduce together. the offsprings of a male and a female ( via sexual reproduction ) are sterile workers. so males and females are just like two sister species that reproduce sexually to create a sterile army to protect and feed them ( fournier et al. ( 2005 ) ). bias it often brings fame to dis... | https://api.stackexchange.com |
##uyon here is a related answer | https://api.stackexchange.com |
in signal processing, two problems are common : what is the output of this filter when its input is $ x ( t ) $? the answer is given by $ x ( t ) \ ast h ( t ) $, where $ h ( t ) $ is a signal called the " impulse response " of the filter, and $ \ ast $ is the convolution operation. given a noisy signal $ y ( t ) $, is... | https://api.stackexchange.com |
to all those who said β yes β i β ll offer a counter - point that the answer is β no β, by design. those languages will never be able to match the performance of statically compiled languages. kos offered the ( very valid ) point that dynamic languages have more information about the system at runtime which can be used... | https://api.stackexchange.com |
analysis and optimisation. | https://api.stackexchange.com |
ok, it seems that user21820 is right ; this effect is caused by both the foreground and the background objects being out of focus, and occurs in areas where the foreground object ( your finger ) partially occludes the background, so that only some of the light rays reaching your eye from the background are blocked by t... | https://api.stackexchange.com |
, once the focus is moved slightly. in the first image below, the camera is focused slightly in front of the background plane, while in the second image, it is focused slightly behind the plane : you can clearly see that, with the focus between the grid and the sphere, the grid lines close to the sphere appear shifted ... | https://api.stackexchange.com |
shows the setup used to take the other three photos. addendum 2 : before the comments below were cleaned out, there was some discussion there about the usefulness of this phenomenon as a quick self - diagnostic test for myopia ( nearsightedness ). while i am not an opthalmologist, it does appear that, if you experience... | https://api.stackexchange.com |
there are four comments on this reddit thread that may be on to something : by silver _ pc : could it be a form of'paper towns'on maps - aka fictitious entry to identify direct copies? by toybuilder : not that they are necessarily doing this, but i've heard it said that mass manufacturers will keep removing capacitors ... | https://api.stackexchange.com |
uncommon. you do what's cheapest / most profitable which is not always the least wasteful option. by coppernickus : there are other planes in a tablet : the display and case. maybe the answer lies in the third dimension. might there be a brush / spring contact or some other connection on another layer of the device tha... | https://api.stackexchange.com |
i think that one of your problems is that ( as you observed in your comments ) neumann conditions are not the conditions you are looking for, in the sense that they do not imply the conservation of your quantity. to find the correct condition, rewrite your pde as $ $ \ frac { \ partial \ phi } { \ partial t } = \ frac ... | https://api.stackexchange.com |
x } + v \ phi \ right ) ( - 10 ) + \ int s ( x, t ) dx $ $ now, the two central terms vanish thanks to the boundary conditions. integrating in time, we obtain $ $ \ int _ 0 ^ t \ int \ frac { \ partial \ phi } { \ partial t } dx dt = \ int _ 0 ^ t \ int s ( x, t ) dx dt $ $ and if we are allowed to switch the first two... | https://api.stackexchange.com |
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