question stringlengths 37 38.8k | group_id stringlengths 2 6 | sentence_embeddings listlengths 768 768 |
|---|---|---|
<p>What does it mean if the F value in one-way ANOVA is less than 1?</p>
<p>Remember the F-ratio is</p>
<p>$$\frac{\sigma^2+\frac{r\times\sum_{i=1}^t \tau_i^2}{t-1}}{\sigma^2}$$ </p> | g24007 | [
-0.017372164875268936,
0.013821491040289402,
-0.04325496405363083,
-0.013701587915420532,
0.028196197003126144,
-0.019233446568250656,
0.04277655482292175,
-0.02440597489476204,
-0.009400955401360989,
-0.020561816170811653,
-0.051345743238925934,
0.005039445590227842,
-0.003478779224678874,
... |
<p>We have already worked in predicting chemical compound activity using "classical" neural networks. Now there is all this hype about deep learning. I wonder if you know cases where predictive ability has dramatically increased going from classical to deep neural networks.</p> | g46521 | [
-0.0016534210881218314,
0.03143297880887985,
0.022473201155662537,
0.01941601373255253,
0.006788968574255705,
-0.09730775654315948,
0.01593468338251114,
0.04159786179661751,
0.015194159932434559,
-0.08656797558069229,
-0.0016015504952520132,
0.060190871357917786,
0.0321434922516346,
-0.053... |
<p>I'd like to use R to generate two correlated series that follow IMA(1,1) process.
rho is a correlation between the error terms, but when I changed the rho the plot does not change. Is it wrong if I use <code>d[i,] <- d[i-1,] - theta*(e[i-1,]+e[i,])</code> ?</p>
<pre><code>rho < 0.1
mu <- c(400,400)
theta... | g350 | [
0.018074210733175278,
-0.07431161403656006,
0.017575975507497787,
-0.03890420123934746,
-0.009510975331068039,
-0.028531095013022423,
0.07511173188686371,
-0.00025512429419904947,
-0.0211610309779644,
-0.016914410516619682,
-0.008143143728375435,
0.0726177990436554,
0.022807465866208076,
-... |
<p>There is a catalog of noninformative priors over here:</p>
<p><a href="http://www.stats.org.uk/priors/noninformative/YangBerger1998.pdf" rel="nofollow">http://www.stats.org.uk/priors/noninformative/YangBerger1998.pdf</a></p>
<p>in page 11, they give the noninformative Jeffreys prior for the Dirichlet distribution.... | g10841 | [
-0.0027816102374345064,
-0.02861575409770012,
-0.013067313469946384,
-0.03975282236933708,
0.01579085923731327,
-0.0039091347716748714,
0.03853969648480415,
0.0200030580163002,
-0.02738969400525093,
-0.05590996518731117,
-0.01736639440059662,
0.047749605029821396,
0.022198280319571495,
-0.... |
<p>I was trying k-medoids algorithm for clustering in R, and just removing stopwords is taking hours. After I removed stopwords, I let the algorithm run overnight and it wasn't done after 8-9 hours. I am trying to cluster 40.000 documents, what alternatives do I have? Should I wait it out? I am just afraid that it will... | g65457 | [
0.05620133876800537,
-0.04109930619597435,
0.0013809711672365665,
-0.056570135056972504,
-0.015306815505027771,
-0.05257905274629593,
0.03049538843333721,
0.05133580416440964,
0.018068669363856316,
0.025186747312545776,
-0.022892706096172333,
-0.02269435115158558,
0.029467284679412842,
-0.... |
<p>I was wondering if anyone could explain the difference between balanced accuracy which is</p>
<pre><code>b_acc = (sensitivity + specificity)/2
</code></pre>
<p>and f1 score which is:</p>
<pre><code>f1 = 2*precision*recall/(precision + recall)
</code></pre> | g65458 | [
0.043014030903577805,
-0.03313593566417694,
0.0003909564984496683,
0.019482659175992012,
0.061245400458574295,
-0.019303958863019943,
0.05262121185660362,
0.039346739649772644,
-0.006076062563806772,
-0.053019288927316666,
-0.05160970240831375,
0.05257224664092064,
0.015765151008963585,
-0... |
<p>A magazine wants to know if the online viewers are more than its printed copy buyers. </p>
<p>Which statistics test is the best to use, the t-test or Wilcoxon signed rank or Mann–Whitney U? </p>
<p>If I have less than $30$ days, is it correct that I should not use t-test since it is not a normal distribution? </p... | g24013 | [
0.013272309675812721,
-0.009890051558613777,
-0.00004327928036218509,
-0.030026204884052277,
-0.01436174288392067,
-0.03227587416768074,
0.02564801089465618,
0.0046804421581327915,
-0.0066305119544267654,
-0.010214313864707947,
0.04736872389912605,
-0.014396090060472488,
0.010374391451478004... |
<p>I am recently learning to use support vector machine as classification.
I have some question about it and hope that it is not a dumb question.</p>
<p>As far as I know,
For multinomial logistic model for classification, the error terms is assumed to be i.i.d double-exponential distribution.
For probit model, it is a... | g39846 | [
0.018300140276551247,
0.030365707352757454,
-0.0032452105078846216,
0.024555867537856102,
0.01846340298652649,
-0.05710510164499283,
-0.003087607678025961,
0.00019547635747585446,
-0.0748606026172638,
-0.003441500710323453,
0.01145862229168415,
0.018360793590545654,
0.05623513460159302,
0.... |
<p>I am doing a Poisson regression analysis and have found that the type of programme a student is enrolled on to does not have a significant effect on the outcome. When it comes to writing out the fitted equation would I need to include the programme if it does not have an effect? </p> | g65459 | [
0.00007166847353801131,
-0.007870052009820938,
0.005084753502160311,
-0.05884324759244919,
0.014119020663201809,
0.01684904657304287,
-0.0010790755040943623,
0.04841911792755127,
0.002104333369061351,
-0.05411873012781143,
-0.013412661850452423,
0.004798213951289654,
-0.010732942260801792,
... |
<p>An example of a good measure of class separability in linear discriminant learners is Fisher's linear discriminant ratio. Are there other useful metrics to determine if feature sets provide good class separation between target variables? In particular, I'm interested in finding good multivariate input attributes for... | g40089 | [
-0.06289977580308914,
-0.029476294293999672,
0.01130767073482275,
-0.05504874140024185,
-0.021467620506882668,
-0.061317749321460724,
0.003812560345977545,
0.021524829789996147,
-0.01406808290630579,
-0.008076603524386883,
0.02322063222527504,
0.019735565409064293,
0.02414063923060894,
-0.... |
<p>When obtaining MCMC samples to make inferences on a particular parameter, what are good guides for the minimum number of <strong>effective samples</strong> that one should aim for?</p>
<p>And, does this advice change as the model becomes more or less complex?</p> | g65460 | [
-0.017747411504387856,
-0.013316916301846504,
0.007678020279854536,
-0.029871080070734024,
-0.008299486711621284,
-0.048337001353502274,
-0.013538217172026634,
0.05222111567854881,
-0.03297040984034538,
0.008966973051428795,
0.0013399276649579406,
-0.02937784604728222,
0.060283221304416656,
... |
<p>I'm having a bit trouble understanding the blue dotted lines in the following picture of autocorrelation function:
<img src="http://i.stack.imgur.com/JMBN8.png" alt="enter image description here"></p>
<p>Could someone give me a simple explanation, what they are telling me x) Thnx</p> | g65461 | [
0.02297212742269039,
-0.006527272053062916,
-0.01584179885685444,
-0.038751810789108276,
0.05839361622929573,
0.00682522589340806,
0.10098651796579361,
0.004057164769619703,
-0.024589555338025093,
-0.06772923469543457,
-0.036354582756757736,
0.05244050920009613,
0.038432247936725616,
0.001... |
<p>New to MCMC.</p>
<p>I have a model, saying
$$Y_i=\beta_0+\beta_1x_{i1}+\beta_2x_{i2}+\frac{e_i}{\sqrt{\mu}}$$
where $x_{ij}$ are fixed covariates, $e_i\sim N(0,1)$, $\beta_0$, $\beta_1$, $\beta_2$ and $\mu$ are unknown parameters, with the prior distribution for parameters $\beta_i\sim N(0,1)$ and $\mu\sim \Gamma(0... | g46523 | [
0.02748069539666176,
-0.06852640956640244,
0.008789886720478535,
-0.05792665109038353,
0.018026797100901604,
-0.017423588782548904,
0.0387449786067009,
-0.002706293249502778,
-0.005095703527331352,
0.015122944489121437,
-0.012950555421411991,
0.04954270273447037,
-0.03918052092194557,
0.02... |
<p>How can I compare whether classifiers outcome is significantly different?</p>
<p>I have a relatively small data set which I'm trying to classify. My training set consists of 24 items come from two different groups, 12 items from each group. each item has two properties. I have 12 new items which I would like to cl... | g46524 | [
-0.012261433526873589,
-0.02861425280570984,
-0.0037815470714122057,
-0.04754771664738655,
0.03916867449879646,
-0.050905145704746246,
0.030777838081121445,
-0.0034000608138740063,
-0.054837945848703384,
-0.04882541671395302,
-0.007170048076659441,
0.04266825690865517,
0.035775527358055115,
... |
<p>A beginner's question about the Pearson's residual within the context of the chi-square test for goodness of fit:</p>
<p>As well as the test statistic, R's <code>chisq.test</code> function reports the Pearson's residual:</p>
<pre><code>(obs - exp) / sqrt(exp)
</code></pre>
<p>I understand why looking at the raw d... | g24019 | [
0.029492506757378578,
-0.02757798507809639,
0.004716694355010986,
-0.03643094375729561,
-0.02800660952925682,
-0.02849743701517582,
0.025148024782538414,
0.05600448697805405,
-0.020268922671675682,
-0.053326718509197235,
-0.02699032984673977,
0.016207009553909302,
0.029567983001470566,
-0.... |
<p>I have two data generating processes that are independent Bernoulli processes with probabilities of success $p_A$ and $p_B$. I am taking repeated samples from these two data generating processes, so the distribution of each set of observations is an independent binomial.</p>
<p>I know the value of $p_A$ and $p_B$ b... | g24020 | [
0.004247562028467655,
-0.015632672235369682,
-0.005355381406843662,
-0.021308783441781998,
-0.004194455686956644,
0.008317427709698677,
-0.019361667335033417,
0.007628319319337606,
-0.06543539464473724,
-0.0665920078754425,
-0.03729962557554245,
0.024389317259192467,
0.026402045041322708,
... |
<p>I have data in which I observe the following pattern:
Variable A correlates with variable C
Variable B correlates with variable C
BUT variable A and B do not correlate with each other, even though they are theoretically very similar.</p>
<p>What could cause this?
Variable C causing the other 2 is very unlikely theo... | g49697 | [
0.05030573904514313,
-0.048049453645944595,
0.018561501055955887,
-0.054939042776823044,
0.04671794921159744,
0.035282306373119354,
0.031534481793642044,
0.031368229538202286,
-0.00879268441349268,
-0.03594013303518295,
0.016109298914670944,
-0.01737196557223797,
-0.03808990493416786,
0.04... |
<p>I have a dataset of gambling expenditure, income, verbal reasoning test scores and gender.</p>
<p>I tried two different methods for fitting a linear regression:</p>
<pre><code>mvr.F <- lm(gamble ~ income + verbal, subset=gender=="female")
mvr.M <- lm(gamble ~ income + verbal, subset=gender=="male")
</code></... | g65462 | [
0.02784307301044464,
-0.05292719975113869,
-0.000558574334718287,
-0.025707298889756203,
0.0024993291590362787,
-0.03825785592198372,
-0.0008930708281695843,
-0.03029307909309864,
-0.06206049770116806,
0.012565860524773598,
-0.010471074841916561,
-0.00026679105940274894,
0.0506325401365757,
... |
<p>I don't mean a value close to zero (rounded to zero by some statistical software) but rather a value of literally zero. If so, would it mean that the probability the null hypothesis is true is also zero? What are (some examples) of statistical tests that can return results of this sort?</p> | g29722 | [
0.030399391427636147,
0.018031004816293716,
0.013493195176124573,
-0.03991037607192993,
0.00123287970200181,
-0.015875259414315224,
-0.0290143471211195,
-0.006704599596560001,
-0.02466277964413166,
-0.06679584830999374,
0.0053347996436059475,
0.009959458373486996,
0.021438974887132645,
-0.... |
<p>I saw this question in UIUC's <a href="http://courses.engr.illinois.edu/ece313/homework/ps13.pdf" rel="nofollow">probability class homework</a> and it got me curious on how to solve it.</p>
<hr>
<p>Suppose $X$ and $Y$ are jointly Gaussian such that $X \sim N(0, 9)$, $Y \sim N(0, 4)$; and the correlation coefficien... | g65463 | [
-0.004827171564102173,
0.011178532615303993,
-0.020362069830298424,
-0.017220858484506607,
0.04515165090560913,
0.03182132542133331,
0.04218875616788864,
-0.01765350066125393,
-0.023659124970436096,
-0.011579836718738079,
-0.05238120257854462,
0.044058382511138916,
-0.017086703330278397,
0... |
<p>I would like to understand better the derivation of the inter-arrival time for a nonhomogeneous Poisson process. Can any one supply a link to a nice clear derivation? I'm only interested in the time to the first event so the survival function would be great but general case is fine. The only references I can find es... | g65464 | [
0.016760116443037987,
-0.019580326974391937,
-0.013962570577859879,
-0.03874204307794571,
0.019639410078525543,
-0.0010552129242569208,
0.0201956145465374,
0.025554109364748,
-0.08193892985582352,
0.006853397935628891,
-0.049378663301467896,
0.013432838022708893,
-0.022994408383965492,
-0.... |
<p>I've worked with certain causal/predictive techniques when handling two time series, but this problem is different from what I am used to and I'm not sure how to proceed.</p>
<p>I would like to see the causal influence of a single event on multiple time series. For example, an earthquake on a particular day having ... | g37572 | [
0.05631546303629875,
0.018190884962677956,
0.021456502377986908,
-0.007933404296636581,
-0.018143074586987495,
-0.07998086512088776,
0.05559512600302696,
0.03881289064884186,
-0.036910802125930786,
-0.04941694065928459,
0.037831105291843414,
-0.022036155685782433,
0.069892019033432,
0.0421... |
<p>Unexpectedly for me (!) I've recently learnt that: </p>
<p><em>"We have assumed that the <strong>error terms</strong>, $\epsilon_{ij}$, of the variates in each sample will be <strong>independent</strong>, that the <strong>variances</strong> of the error terms of the several samples will be <strong>equal</strong>, ... | g37573 | [
0.043215930461883545,
-0.038895830512046814,
-0.015813324600458145,
0.008925377391278744,
-0.02733798511326313,
-0.005764839705079794,
-0.019337493926286697,
-0.01804143190383911,
-0.03279605507850647,
0.022781796753406525,
-0.06561380624771118,
0.004901830106973648,
0.010262276977300644,
... |
<p>I am trying to do a few tests in Minitab and I don't understand why they are not working out. </p>
<p>First, my data in minitab has several columns: <code>Class Name Gender Height Age</code>, where </p>
<ul>
<li><code>Class</code> has two values {A,B};</li>
<li><code>Name</code> is the name of the students; </li>... | g24028 | [
0.02946985326707363,
-0.036585964262485504,
0.0013758698478341103,
0.0019412182737141848,
0.020847350358963013,
0.03823305666446686,
0.04732139781117439,
-0.03426693379878998,
-0.06551353633403778,
-0.062055863440036774,
-0.025792183354496956,
0.012458635494112968,
0.07284338027238846,
-0.... |
<p>The $n^{th}$ moment of a distribution can be estimated from a vector of samples $(x_1,x_2,...x_k)$ by:
$$
\sum_{i=1}^{k} x_i^n
$$
Now, let's say I've calculated the first $m$ moments for my distribution. How do I then go about doing the normal things I would do with my distribution, like finding the $PDF(x)$ or $C... | g65465 | [
-0.014628817327320576,
-0.041503772139549255,
-0.03396526351571083,
-0.025472143664956093,
-0.04389892891049385,
-0.07042445987462997,
0.00036805265699513257,
0.003928035032004118,
-0.0626533031463623,
0.010733552277088165,
-0.055559732019901276,
-0.009336316958069801,
0.0285220704972744,
... |
<p>In epidemiology, this occurs often: Old people are less prone to the influence of risk factors. For example, the Framingham risk score, which tries to estimate cardiovascular risk, gives 8 or 9 points to smokers in their twenties and thirties, but only 1 point to those in their seventies (more points correspond to h... | g65466 | [
0.03022109903395176,
-0.011923764832317829,
-0.006202482618391514,
0.000278267078101635,
-0.007802717387676239,
0.027631422504782677,
0.017953142523765564,
-0.013206025585532188,
0.0496654286980629,
-0.031201057136058807,
0.04006389155983925,
0.024303516373038292,
0.08233687281608582,
0.01... |
<p>I have a a set of films, and for each films, a set of reviews - varying between 1 review and several hundred reviews for each film. Each review has a star rating from 1 to 5. </p>
<p>I am using Wilson's confidence interval for a Bernoulli parameter to estimate whether the film is likely to be good or not, taking in... | g24031 | [
-0.039876993745565414,
-0.018822968006134033,
-0.010520313866436481,
0.01793777570128441,
0.013869645074009895,
0.022114166989922523,
-0.01363944448530674,
0.04259008914232254,
-0.03079892508685589,
-0.03770943358540535,
-0.021749507635831833,
0.042268648743629456,
0.030455244705080986,
0.... |
<p>I have some data similar to this</p>
<pre><code>died age hospital
0 75 AA
0 88 AA
1 81 AA
0 77 AA
1 65 AA
0 41 AA
0 66 BA
1 81 BA
0 82 BA
1 64 BA
0 65 BA
1 52 BA
</code></pre>
<p>I was asked to calculate "age adjusted... | g65467 | [
-0.00618915306404233,
-0.03980078175663948,
-0.003927558194845915,
-0.030841022729873657,
0.004530355799943209,
-0.025695284828543663,
0.020401081070303917,
0.056909989565610886,
-0.031147269532084465,
-0.041841618716716766,
0.03907156363129616,
-0.001592093612998724,
0.10454211384057999,
... |
<p>I used to get SPSS output earlier with the decision. I attach a screenshot of how it used to be. But now I don't get an output like this, instead I get just a normal table without the decision column. Can someone help please.
<img src="http://i.stack.imgur.com/PVQlx.png" alt="Screenshot of how it used to be"></p> | g44035 | [
0.009778513573110104,
-0.022333543747663498,
0.010991303250193596,
-0.021210964769124985,
-0.018525686115026474,
-0.0360921248793602,
-0.023283639922738075,
-0.0110002551227808,
-0.055926136672496796,
-0.03796033933758736,
0.02775588631629944,
0.02864116244018078,
0.062222838401794434,
0.0... |
<p>I am given a paper with Kaplan-Meier curve. I'd like "reverse-engineer" the chart to get the original data (without the censoring events, as they are difficult to discern in my low quality copy).</p>
<p>I've seen the tool for this task on the Net, but it was long time ago and forgot its name. </p>
<p>Can someone ... | g49693 | [
0.03370588645339012,
-0.03871894255280495,
-0.01091633178293705,
-0.022495873272418976,
-0.010720862075686455,
-0.05395711585879326,
0.022262759506702423,
0.009924580343067646,
-0.04570479318499565,
-0.0038156609516590834,
0.023633204400539398,
0.036660484969615936,
0.08413705229759216,
-0... |
<p>The question arises in a <a href="http://crypto.stackexchange.com/q/5886/555">cryptographic context</a> involving a regulatory test of a physical source or random bits, with null hypothesis that they are independent and unbiased. $n$ samples of 4 bits are drawn ($n=128$ or $80$), the number of samples $O_i$ in each ... | g44038 | [
-0.03383380547165871,
0.03168598189949989,
-0.02113659679889679,
-0.04611380025744438,
0.00002456081347190775,
0.00411593122407794,
0.011356945149600506,
0.003751302370801568,
-0.029559722170233727,
-0.005472361575812101,
-0.004604509100317955,
0.029788296669721603,
0.056664448231458664,
0... |
<p>I am a first-year grad student in Computer Science, and I need some help with a problem that I think is statistically oriented. I have taken a statistics course, but it was abysmal and I haven't had time to rectify that. But anyway, my problem stems from a project I'm working on involving genetic programming, where ... | g24036 | [
-0.021481912583112717,
-0.006773265078663826,
-0.003688668832182884,
-0.023954706266522408,
-0.038611918687820435,
-0.02145526558160782,
-0.0052666743285954,
0.020345380529761314,
-0.020985467359423637,
-0.027157487347722054,
-0.03813678398728371,
0.039317600429058075,
-0.01557066012173891,
... |
<p>I stumbled upon the following problem:</p>
<p>Given 'n' dice with 'm' faces with values 1 to m and a number 'x' what is the probability that the sum of the numbers on the 'm' dice is greater than or equal to 'x'? That is $m \le x \le n.m$ find $P(sum \ge x)$ </p>
<p>Now, this 'almost approximates' a normal distri... | g65468 | [
-0.013023573905229568,
0.023887166753411293,
-0.016333723440766335,
-0.04783833771944046,
-0.04117649793624878,
-0.03422818332910538,
0.006934499368071556,
-0.012150880880653858,
-0.02194102481007576,
-0.019794583320617676,
-0.028686797246336937,
0.02774728275835514,
0.07846888899803162,
0... |
<p>I am currently analyzing several repeated measures with several treatments. That is: 33 individuals and 4 different conditions. The box plots that are shown from left to right indicate the treatments in the following order: control, first treatment, second treatment, and third treatment.</p>
<ul>
<li>Before adding ... | g49163 | [
0.02628692425787449,
-0.017164111137390137,
-0.018627163022756577,
-0.027609359472990036,
0.019968952983617783,
-0.0416819266974926,
0.026605237275362015,
0.00650049326941371,
-0.018313031643629074,
-0.019903119653463364,
0.011284944601356983,
0.0013981478987261653,
-0.0025913005229085684,
... |
<p>I have a CSV dataset which contains <code>mean</code> (Numeric), <code>spread</code> (Numeric), <code>review</code> (string), <code>class</code> (Nominal) attributes. When I run J48 Decision tree with this dataset in Weka I get 100% accuracy even after cross validation (20 folds), and I believe this is wrong. So I c... | g24039 | [
0.005089321173727512,
-0.06233860179781914,
0.02773168310523033,
-0.037441469728946686,
0.017895353958010674,
0.01996617019176483,
0.01778569631278515,
0.05040488392114639,
-0.033514559268951416,
-0.00816365983337164,
0.0021602148190140724,
0.05259682983160019,
0.0276494137942791,
0.000936... |
<p>I have two continuous DVs (measurements taken on individual fish), one continuous individual level IV (fish's size), and two site-level IVs (PC1 and PC4). Sites are either take or no take. There are 13 sites and 178 observations. This is what some of that data looks like</p>
<pre><code>Site Status DV1 DV2 Size ... | g29773 | [
0.008280009031295776,
-0.08346229791641235,
-0.014760006219148636,
-0.03386421874165535,
0.05096159130334854,
-0.018842574208974838,
0.11679054796695709,
0.025820836424827576,
-0.02832089550793171,
-0.02497567981481552,
-0.026980243623256683,
0.042498745024204254,
0.00614299438893795,
0.00... |
<p>In my previous job as a statistics teacher, I was involved in studies mostly as an advisor on a general level. Not that much hands-on experience from doing the actual sampling or data cleaning, activities which are both important and time-consuming in practice. In my present job, I am the one who is supposed to know... | g24041 | [
0.029219230636954308,
-0.002021153923124075,
0.0007507474510930479,
-0.023322714492678642,
-0.07722897082567215,
-0.049153655767440796,
-0.007927319966256618,
0.012059045024216175,
0.0020664783660322428,
-0.0012799421092495322,
0.0795617625117302,
-0.04466772451996803,
0.10379840433597565,
... |
<p>I am trying to see which distribution will best fit the data I am working on. The dataset is as following:</p>
<pre><code>Site Nausea headache Abdominal Distension
1 17 5 10
2 12 8 7
.....
</code></pre>
<p>... | g65469 | [
0.021896498277783394,
-0.0029565913137048483,
-0.007505693472921848,
-0.02894657291471958,
-0.008866729214787483,
-0.07311029732227325,
-0.009834760800004005,
0.04868727922439575,
-0.02450650930404663,
-0.03360956534743309,
0.002393971662968397,
-0.031093649566173553,
0.0719977393746376,
0... |
<p>I have some data from two groups of subjects. Within each group, the correlation is calculated on some biological measures between any pair of two subjects. In other words, a group of $N$ subjects gives me $N(N-1)/2$ correlation coefficients, which show the similarity between any pair of two subjects. The biologist ... | g65470 | [
-0.039496831595897675,
-0.052193526178598404,
0.011286321096122265,
-0.026988156139850616,
0.004029125906527042,
-0.025050653144717216,
0.07718146592378616,
-0.009866390377283096,
-0.05780324339866638,
0.013555836863815784,
0.010616024024784565,
0.016640005633234978,
-0.003760145977139473,
... |
<p>Suppose I want to learn a joint distribution $p(x_1, \ldots, x_n)$ and have a collection of samples $x^k_1, \ldots, x^k_n$ for each $k$. Assume some values $x^k_i$ are unknown, so the samples are incomplete. What are some ways to learn the distribution?</p>
<p>I would be interested in an answer for a general distri... | g65471 | [
0.015623846091330051,
0.014056194573640823,
0.00269759027287364,
-0.03986012190580368,
-0.016813894733786583,
-0.018471557646989822,
-0.05011340603232384,
-0.04147900268435478,
-0.021544700488448143,
-0.017333613708615303,
-0.0001284822792513296,
0.009203337132930756,
0.0760381892323494,
0... |
<p>I need to fit a gamma distribution that is shifted to the left and truncated at zero (so that for example, my data may only come from the right tail of the full distribution, and I don't have any observations less than zero). </p>
<p>I can find the alpha and beta parameters to fit a regular old two parameter gamma... | g65472 | [
0.03719402849674225,
-0.06753098219633102,
-0.001865434111095965,
-0.05455067381262779,
0.01780034974217415,
0.02323341555893421,
-0.015346045605838299,
0.04524197429418564,
-0.07312701642513275,
-0.006791501771658659,
-0.016875697299838066,
-0.01814388483762741,
0.0057487161830067635,
0.0... |
<p>How do I fit the parameters of a t-distribution, i.e. the parameters corresponding to the 'mean' and 'standard deviation' of a normal distribution. I assume they are called 'mean' and 'scaling/degrees of freedom' for a t-distribution?</p>
<p>The following code often results in 'optimization failed' errors.</p>
<pr... | g65473 | [
0.028229190036654472,
0.030275285243988037,
-0.0066665844060480595,
-0.07366134226322174,
-0.007238631136715412,
0.04864731431007385,
0.000029704187909374014,
0.01922208070755005,
-0.0855172798037529,
0.011549278162419796,
-0.027836402878165245,
-0.09540082514286041,
0.06281806528568268,
0... |
<p>We have a question about how to deal with missing values/gaps within sequences. We like to set up our own substitution-cost matrix for the Optimal Matching process. As far as we know, TraMiner allows creating own cost matrices - but only in case there are no missing values. If there are missing values there is a def... | g65474 | [
0.036532361060380936,
-0.04307938367128372,
-0.023984652012586594,
-0.03235528990626335,
0.010713614523410797,
-0.029322143644094467,
0.025153061375021935,
0.01763320155441761,
0.0195174440741539,
-0.010627967305481434,
-0.01689348742365837,
-0.04606574773788452,
0.02528141811490059,
0.034... |
<p>I'd like to determine the best approach to determining effect sizes for a set of experimental data with multiple correlated responses. Due to repeated measurements and high correlation between responses, I know that a simple multiple linear regression model obviously isn't the answer.</p>
<p>The situation: atmosphe... | g32434 | [
-0.014517574571073055,
-0.039280910044908524,
-0.005467786453664303,
-0.05693027749657631,
-0.03213905543088913,
-0.030995650216937065,
0.039484653621912,
0.00930977612733841,
-0.03794611617922783,
-0.029622429981827736,
0.0337894968688488,
-0.011937441304326057,
0.009734738618135452,
0.02... |
<p>Stack Exchange, as we all know it, is a collection of Q&A sites with diversified topics. Assuming that each site is independent from each other, given the stats a user has, how to compute his "well-roundedness" as compared to the next guy? What is the statistical tool I should employ?</p>
<p>To be honest, I don... | g65475 | [
-0.03507642820477486,
0.013067086227238178,
-0.0030073807574808598,
-0.07310071587562561,
0.006580590736120939,
-0.012359341606497765,
0.050465114414691925,
-0.0014217505231499672,
-0.007316563278436661,
-0.02289186231791973,
0.0148891881108284,
0.04395560920238495,
0.08154796063899994,
0.... |
<p>I'm just reading the book "R in a Nutshell".
And it seems as if I skipped the part where the "." as in "sample.formula" was explained. </p>
<pre><code>> sample.formula <- as.formula(y~x1+x2)
</code></pre>
<p>Is sample an object with a field formula as in other languages? And if so, how can I find out, what o... | g65476 | [
0.02532860077917576,
0.013762186281383038,
0.007929359562695026,
-0.02592216245830059,
0.0011864883126690984,
-0.03303752467036247,
0.03443630784749985,
0.009856496937572956,
-0.0019427583320066333,
-0.047542281448841095,
-0.08368059992790222,
0.060807231813669205,
0.06437597423791885,
-0.... |
<p>Instead of perusing through many more textbooks, I thought it's easier to ask here. Say I would like to express the mean for a variable with a certainty of 95 percent, how exactly do ("should") I do this?</p>
<p>Maybe like:</p>
<ul>
<li><p>$x_{P = 95\%} = 373.334$ mm $\pm 8.82$ or</p></li>
<li><p>$x (P = 95\%) = 3... | g65477 | [
0.02770092897117138,
-0.025124618783593178,
0.0013157667126506567,
-0.05207762494683266,
0.027361171320080757,
-0.019313203170895576,
-0.03353257477283478,
0.015742987394332886,
-0.04202033206820488,
-0.011265438050031662,
0.016282862052321434,
0.014357056468725204,
0.01691947504878044,
-0... |
<p>This question builds on my previous question <a href="http://stats.stackexchange.com/questions/96027/forecasting-hourly-time-series-based-on-previous-weeks-and-same-period-in-previo">Forecasting Hourly Time Series based on previous weeks and same period in previous year/s</a>. My project is to forecast the number of... | g65478 | [
0.010149725712835789,
-0.06214815005660057,
0.012891015969216824,
-0.026760727167129517,
-0.02756967395544052,
-0.0007084012031555176,
0.04633095860481262,
-0.031478412449359894,
-0.040357548743486404,
-0.05777890980243683,
0.04158346727490425,
-0.023957885801792145,
0.065294049680233,
0.0... |
<p>Where can I find details of Steel's method for nonparametric multiple comparison with control on line ... ?</p> | g24049 | [
0.04571959003806114,
-0.016750648617744446,
-0.017748767510056496,
-0.0073098973371088505,
0.0158573929220438,
-0.07223198562860489,
0.057164594531059265,
-0.04059477150440216,
-0.07469309121370316,
0.006161245983093977,
-0.031210465356707573,
-0.04488247632980347,
0.06500554829835892,
0.0... |
<p>Is there a standard name for a multinomial choice model where the observations are in the form of binary questions such as "do you prefer A to B" and "do you prefer B to D"? This seems like a common occurrence, and the likelihood is easy enough to write out by hand, but I'm having trouble searching for references.<... | g65479 | [
-0.023758864030241966,
0.004005719907581806,
0.01360986940562725,
-0.015156593173742294,
0.0007823985652066767,
-0.0265912227332592,
-0.005770643707364798,
-0.030365856364369392,
-0.0071864319033920765,
0.01292324811220169,
0.03452335298061371,
-0.03384649381041527,
0.056594718247652054,
0... |
<p>I have an experiment that produces a decimal score representing quality, and a bunch (5-30) of variables that each take on one of a set of discrete states.
- The states are not meaningfully contiguous
- the states are just a set of unrelated discrete values ("foo", "bar")
- The set of states is about 10-... | g24051 | [
0.025992201641201973,
-0.019090883433818817,
0.01984681934118271,
-0.06881403177976608,
0.007220621686428785,
-0.03214363381266594,
-0.008062451146543026,
0.014137675054371357,
0.0005151613731868565,
-0.05023254454135895,
0.021530121564865112,
0.01339117530733347,
0.05662451311945915,
0.03... |
<p>I am reading Ruppert's <a href="http://www.springer.com/statistics/business,+economics+%26+finance/book/978-1-4419-7786-1" rel="nofollow">Statistics and Data Analysis for Financial Engineering</a>, which contains the following theorem:</p>
<blockquote>
<p>Let $Y_1$, $...$ , $Y_n$ be an i.i.d. sample with a CDF $F... | g65480 | [
0.003848469816148281,
0.0006361314444802701,
-0.014630584046244621,
0.00842532142996788,
0.009751264937222004,
-0.0012874673120677471,
0.04741107299923897,
-0.06035261228680611,
-0.054556336253881454,
-0.022900715470314026,
-0.019253894686698914,
0.03957800194621086,
-0.013668577186763287,
... |
<p>I have a few doubts in understanding SVMs intuitively. Assume we have trained a SVM model for classification using some standard tool like SVMLight or LibSVM. </p>
<ol>
<li><p>When we use this model for prediction on test data, the model generates a file having "alpha" values for each test point. If alpha value is ... | g65481 | [
0.01575927808880806,
0.008161167614161968,
0.0075066303834319115,
0.02550278790295124,
0.012494961731135845,
0.008747688494622707,
-0.019706260412931442,
0.0515509732067585,
-0.06513716280460358,
-0.03495665639638901,
-0.016786014661192894,
0.013191360980272293,
0.09107138216495514,
0.0420... |
<p>I have been assigned the task of helping someone who has collected some survey associated data related to some kind of government facilities provided to people. The data corresponding to small scale entrepreneurs across 3 cities who are the providing the services to the customers looks like this (sample data):</p>
... | g65482 | [
0.00912512931972742,
0.05789751559495926,
-0.020602943375706673,
-0.06241162493824959,
-0.041248712688684464,
-0.014877439476549625,
0.024088792502880096,
-0.03151305764913559,
0.006059287115931511,
-0.002523483010008931,
0.06291669607162476,
0.038701772689819336,
0.07167546451091766,
0.01... |
<p>I have a hidden binary random variable Z that can have a value of either 1 or 0. There is some true probability P(Z=1) = z that I do not know.</p>
<p>I also have two separate pieces of "evidence" that give some information about the state of Z: </p>
<ul>
<li>P(Z=1) = x</li>
<li>P(Z=1) = y</li>
</ul>
<p>I'm intere... | g65483 | [
0.04133548587560654,
-0.010072175413370132,
-0.003086936194449663,
0.016259053722023964,
0.017140990123152733,
0.011789927259087563,
-0.03557256609201431,
0.059286974370479584,
-0.039307449012994766,
-0.008389412425458431,
0.02257341518998146,
0.0015745129203423858,
-0.003510831156745553,
... |
<p>I'm testing the residuals of a linear regression using <strong>Breusch-Pagan</strong> Test to detect Heteroscedasticity.</p>
<p>This is the plot of the residuals:
<img src="http://i.stack.imgur.com/28sNL.jpg" alt="Residuals"></p>
<p>and this is the R code:</p>
<pre><code>> library(lmtest)
>
> mod <- ... | g65484 | [
0.014231357723474503,
-0.03856416791677475,
-0.010804599151015282,
-0.02189532481133938,
-0.016553498804569244,
0.022146068513393402,
-0.007397377863526344,
0.0061582899652421474,
-0.03833257779479027,
-0.04229620099067688,
0.0318092405796051,
0.06417804956436157,
0.014586824923753738,
-0.... |
<p>I'd like to convert a factor variable to a numeric one but <code>as.numeric</code> doesn't have the effect I expect. </p>
<p>Below I get summary statistics for the numeric version of the variable based on the original variable. The means keep counting up by 1... perhaps (he speculates) the levels of the factor ha... | g65485 | [
-0.022037100046873093,
-0.03289441019296646,
0.011188819073140621,
-0.05192432180047035,
0.007206260692328215,
-0.013922316022217274,
-0.002074494957923889,
0.05127822980284691,
-0.010241484269499779,
-0.029862849041819572,
0.008849481120705605,
0.027467429637908936,
0.012881972827017307,
... |
<p>I am looking for data sets that contain individual sales data (e.g. the amounts paid by each customer at the cash register of a particular supermarket, or the amounts paid in 10,000 ebay transactions on a given day, or anything like that), without any aggregation. No covariates are required as I am principally inter... | g65486 | [
-0.002250721910968423,
0.052298594266176224,
-0.024799782782793045,
-0.06932596862316132,
-0.020822426304221153,
-0.015548131428658962,
0.057746514678001404,
-0.03847910836338997,
-0.013755185529589653,
-0.050792451947927475,
0.013327201828360558,
-0.019965242594480515,
0.023017900064587593,... |
<p>I am very interested about the potential of statistical analysis for simulation/forecasting/function estimation, etc. </p>
<p>However, I don't know much about it and my mathematical knowledge is still quite limited -- I am a junior undergraduate student in software engineering. </p>
<p>I am looking for a book that... | g65487 | [
0.03005964308977127,
0.0225742906332016,
0.023111088201403618,
0.007749923504889011,
-0.031153835356235504,
-0.015054832212626934,
0.02754846401512623,
-0.020302556455135345,
-0.018805285915732384,
0.00018513061513658613,
0.01621592603623867,
0.03806966170668602,
0.10992692410945892,
-0.00... |
<p>I'm currently writing my thesis, and I received feedback from my professor that i need to show the correlations between all variables during the time span of my research. </p>
<p>N: 291
Years: 11 (2000 - 2010)
Total variables: 25</p>
<p>I have created a correlation matrix in SPSS (using R for the analysis), I hav... | g24063 | [
0.05858195573091507,
-0.05452282354235649,
0.0004590803582686931,
-0.06406994163990021,
-0.00695148017257452,
0.010616092942655087,
0.04396604374051094,
0.028248287737369537,
-0.0038916959892958403,
-0.010192042216658592,
0.03786514326930046,
0.01191609539091587,
0.01505445595830679,
0.068... |
<p>I am looking for a graph or data for relative growth of human body organs, more importantly head size and total body height. </p>
<p>The full data I would like to have—each as a function of time from birth (and preferably until death)—are: </p>
<ol>
<li>Head size, preferably for both male and female,<... | g65488 | [
0.02592495083808899,
0.03273284435272217,
0.0057866391725838184,
-0.04809862747788429,
-0.10728836804628372,
-0.001396345323882997,
0.050370752811431885,
-0.022653575986623764,
-0.030136695131659508,
-0.006474325433373451,
-0.01891270838677883,
-0.006853536702692509,
0.07138682901859283,
-... |
<p>Suppose I have data of this format:</p>
<p>customer, country, location, unit price, traffic, etc. (more nominal/ordinal variables)</p>
<p>I want to know how country affects unit price, how do I go about doing this using </p>
<p>a. some measures of dependence
b. regression models</p>
<p>I'm totally confused as to... | g24067 | [
0.031008083373308182,
-0.03554288670420647,
-0.03799702227115631,
-0.06595734506845474,
0.021445278078317642,
-0.004211935680359602,
-0.0017044148407876492,
0.004475620109587908,
-0.036373790353536606,
-0.022160660475492477,
0.028364863246679306,
0.012115473859012127,
0.02912132255733013,
... |
<p>I have read the <a href="http://www.lancs.ac.uk/~killick/Pub/KillickEckley2011.pdf" rel="nofollow">documentation for this package</a>,but there is one place I don't understand, in page 7 the author set the penalty value to 1.5*log(n), where does this "log(n)" originate from? A bracket on the side indicate it is the ... | g24068 | [
0.03645724430680275,
0.03059031255543232,
-0.026331771165132523,
-0.03324725106358528,
0.023131530731916428,
-0.11484025418758392,
0.10119518637657166,
0.003611703170463443,
-0.07166872173547745,
0.01817680150270462,
-0.031653210520744324,
-0.005425778217613697,
0.052461348474025726,
0.047... |
<p>It is probably an old and simple problem but I do not have a statistical background and I do not know even how to approach it. The problem is: </p>
<p>Given a number of geographical areas in a country (eg: 100), they ask me to choose 4 or 5 of them, and based on the results of those areas, to be able to predict acc... | g24069 | [
-0.02299484610557556,
-0.014737728051841259,
-0.008578895591199398,
-0.030246486887335777,
-0.053250495344400406,
-0.03203738480806351,
0.06484440714120865,
0.042458802461624146,
0.041813191026449203,
0.01642451249063015,
0.04524221271276474,
-0.016682367771863937,
0.0492052398622036,
0.00... |
<p>Models with stochastic trends i.e., structural time series models are useful in some instances. Firstly, it may be hard to identify multiple structural breaks in the deterministic trend when the sample size is small. Secondly, implementing endogenous multiple structural break tests is a demanding exercise. Therefore... | g745 | [
0.0028137429617345333,
0.012332386337220669,
0.01067440677434206,
-0.04269332066178322,
-0.014272402971982956,
-0.01966160535812378,
0.00040724195423536,
0.004236280918121338,
-0.04966951906681061,
-0.005830726586282253,
0.0019554165191948414,
-0.00549380062147975,
-0.005794600583612919,
0... |
<p>I have a set of $n$ measurements, $x_i$, representing distance to a point, and want to find the mean and the standard deviation of the distance, the problem is, I don't know how to take the precision of the measuring equipment into the equation. </p>
<p>The precision of the measuring equipment is given by the produ... | g65489 | [
-0.02549915201961994,
-0.009987175464630127,
-0.021032465621829033,
0.03408303111791611,
0.022963138297200203,
0.011990247294306755,
0.0384964756667614,
0.01321640145033598,
-0.017698340117931366,
-0.015878628939390182,
-0.009156288579106331,
-0.006275024730712175,
-0.02668125182390213,
-0... |
<p>Consider the log likelihood of a mixture of guassians:</p>
<p>$$l(S_n; \theta) = \sum^n_{t=1}logP(x^{(t)}|\theta) = \sum^n_{t=1}log\sum^k_{i=1}p_iP(x^{(t)}|\mu^{(i)}, \sigma^2_i)$$</p>
<p>I was wondering why it was computationally hard to maximize that equation directly? I was looking for either a clear solid intu... | g24072 | [
-0.026350632309913635,
-0.004779500421136618,
-0.019077414646744728,
-0.002421425189822912,
-0.023996248841285706,
0.0011051340261474252,
0.02324083261191845,
0.05719173327088356,
-0.031296830624341965,
0.016672246158123016,
-0.01947135664522648,
-0.0202089361846447,
0.1029479131102562,
-0... |
<p>I'm studying pattern recognition and statistics and almost every book I open on the subject I bump into the concept of <strong>Mahalanobis distance</strong>. The books give sort of intuitive explanations, but still not good enough ones for me to actually really understand what is going on. If someone would ask me "W... | g49761 | [
0.04306352883577347,
0.013873793184757233,
-0.012087205424904823,
-0.041700590401887894,
-0.014839806593954563,
0.01635289564728737,
0.036219559609889984,
0.05771121382713318,
-0.004963533021509647,
-0.011297168210148811,
-0.019969645887613297,
-0.026550890877842903,
0.11752188205718994,
0... |
<p>I am pretty sure it will take a few goes for me to phrase this question correctly but hopefully somebody with relevant knowledge will understand. I also hope this question actually has an answer(s) so that it becomes more than a philosophical discussion- I am aiming to be as specific as possible to avoid this. I als... | g65490 | [
-0.037003811448812485,
0.015744199976325035,
0.018616080284118652,
0.013354405760765076,
-0.023858947679400444,
0.013805897906422615,
0.05712788924574852,
0.017307767644524574,
0.006042012013494968,
-0.00022418393928091973,
-0.007635900285094976,
0.004307059105485678,
0.04617875814437866,
... |
<p>In a presentation today the speaker made the above claim. He said that even if the first stage is mis-specified, the coefficient estimates of the second stage will still be valid. As a lowly graduate student I could not ask for an explanation, so now I begged for your help!</p> | g65491 | [
0.02771291695535183,
-0.003105633659288287,
-0.022132614627480507,
0.03903305530548096,
0.03634238988161087,
0.012436158955097198,
0.05040114000439644,
-0.01457847561687231,
-0.04328387230634689,
-0.00666625564917922,
-0.05431768670678139,
0.055050674825906754,
0.002495299559086561,
0.0008... |
<p>I was studying classification algorithm , LDA (Linear Discriminant Analysis). In this, we have to estimate the mean and variance of predictors, given a particular class. Can I use Bayesian estimation procedure to estimate mean and variance from the data ? Just wanted to know, how much results vary when compared to w... | g65492 | [
-0.00150930171366781,
-0.06449851393699646,
0.03298719599843025,
-0.05635925382375717,
-0.06034713611006737,
-0.048460692167282104,
0.010579610243439674,
0.060967378318309784,
-0.02025286667048931,
-0.030504567548632622,
0.005783552303910255,
0.07254382967948914,
0.03666146844625473,
0.041... |
<p>I am working on a multinomial logistic model. I have the following questions: </p>
<ol>
<li>AIC is asymptotically same as cross-validation, right? is it also true for logistic model? (N ~= 6000, p ~= 20)</li>
<li><p>I perform a forward stepwise regression to my data using the formula for AIC=2k-2log(L) and select ... | g40258 | [
0.014922884292900562,
-0.017387088388204575,
0.01700061373412609,
-0.04555012658238411,
0.02590249478816986,
-0.0764060914516449,
0.0390208400785923,
0.031497735530138016,
-0.058127518743276596,
-0.009245648980140686,
0.002767379628494382,
0.015050025656819344,
0.0718705952167511,
0.047333... |
<p>I was reading <a href="http://anythingbutrbitrary.blogspot.com/2012/04/lm-function-with-categorical-predictors.html" rel="nofollow">"The lm() function with categorical predictors"</a>, and am confused.</p>
<ol>
<li><p>What does the regression model with a categorical predictor look
like, with the following R code:<... | g65493 | [
-0.03297871723771095,
-0.050785839557647705,
-0.005697628948837519,
-0.04466554522514343,
0.040374524891376495,
-0.05037418380379677,
0.026696840301156044,
0.030029885470867157,
-0.053836073726415634,
-0.008456158451735973,
-0.031839147210121155,
0.04237870126962662,
0.07078125327825546,
-... |
<p>I'm trying to build a model to predict the optimal (clock) time for a outbound call to a person. The goal is to maximize reachability. The historical data contains some input variables (age, profession, sex, etc), the time of the call-attempt and the indicator whether the person has been contacted or not. I have to ... | g24075 | [
-0.012833315879106522,
0.01419444102793932,
0.011024868115782738,
-0.001512291026301682,
-0.03698571026325226,
-0.04938190430402756,
-0.035622552037239075,
-0.012601182796061039,
-0.019360264763236046,
0.015223639085888863,
-0.011572672054171562,
0.005575877148658037,
0.05461415275931358,
... |
<p>I was wondering what the counterpart to Pearson product-moment correlation would be in a Bayesian framework. Or if there are many alternatives, what would be the most convenient or conventional method. I know that I could do Bayesian linear regression analysis but then I have to assume that I have one dependent and ... | g44085 | [
0.019856102764606476,
-0.0287198256701231,
-0.0016480848425999284,
-0.04037083685398102,
-0.029035231098532677,
-0.01947941444814205,
-0.006787000689655542,
-0.00028951745480298996,
-0.028723886236548424,
-0.01703590527176857,
0.011370341293513775,
-0.018721995875239372,
0.020937073975801468... |
<p>I have two different measuring instruments, A and B, both measure the same physical quantity but with different unit of measures: $u_A$ and $u_B$.</p>
<p>A is a reference instrument.</p>
<p>I measured a reference part $L$ $n$ times with A and I get the $n$ values $L_{Ai}$ ($i=1 \dots n$) expressed in term of the ... | g44086 | [
0.006662319879978895,
-0.019129417836666107,
-0.02624957449734211,
-0.04501236975193024,
0.03088851273059845,
-0.0481017604470253,
0.01088850200176239,
0.008142415434122086,
0.01207948848605156,
0.009556809440255165,
0.00044655828969553113,
0.015828143805265427,
0.011239304207265377,
0.006... |
<p>What is the best statistical procedure to identify the standard error in a multidimensional data set? The following is a made-up data sets of 10 print runs:</p>
<pre><code>dataSet <- function(x,y){
data <- lapply(1:4, function(x)
do.call(cbind,do.call(cbind,
lap... | g65494 | [
0.06571189314126968,
-0.026373112574219704,
-0.007897278293967247,
-0.06845260411500931,
-0.020704761147499084,
-0.02191203087568283,
0.05298207327723503,
0.010635565035045147,
-0.06577817350625992,
-0.00109204335603863,
-0.016232937574386597,
0.023131968453526497,
0.03522187098860741,
0.0... |
<p>Using data and answers from this <a href="http://stats.stackexchange.com/questions/4544/how-does-one-do-a-type-iii-ss-anova-in-r-with-contrast-codes">question</a> I was trying to test the hypothesis $H_0:-3\mu_1-\mu_2+\mu_3+3\mu_4=0$</p>
<pre><code>set.seed(42)
sample.data <- data.frame(IV=factor(rep(1:4, each=2... | g24082 | [
0.016504764556884766,
-0.06499083340167999,
-0.01384583581238985,
-0.025555694475769997,
0.022356072440743446,
-0.024764791131019592,
0.04066848009824753,
0.018412629142403603,
-0.001524916267953813,
-0.0311361625790596,
-0.03934020921587944,
0.05326707661151886,
0.003193326760083437,
0.01... |
<p>I am working with a large amount of time series. These time series are basically network measurements coming every 10 minutes, and some of them are periodic (i.e. the bandwidth), while some other aren't (i.e. the amount of routing traffic).</p>
<p>I would like a simple algorithm for doing an online "outlier detecti... | g49496 | [
0.06800635904073715,
-0.06015631556510925,
0.0026599313132464886,
-0.02515435591340065,
-0.04961701110005379,
-0.05164259299635887,
0.0347125418484211,
0.008377614431083202,
-0.06124788522720337,
-0.0065072993747889996,
0.020267825573682785,
0.01623191125690937,
0.008073057979345322,
-0.00... |
<p>I have collected responses from 85 people on their ability to undertake certain tasks. </p>
<p>The responses are on a five point Likert scale:</p>
<p>5 = Very Good,
4 = Good,
3 = Average,
2 = Poor,
1 = Very Poor,</p>
<p>The mean score is 2.8 and the standard deviation is 0.54.</p>
<p>I understand what the mean a... | g65495 | [
-0.03278149291872978,
-0.01774069108068943,
-0.006203684490174055,
-0.0341254398226738,
-0.007807393558323383,
0.007586830761283636,
0.01191950123757124,
0.027085382491350174,
0.005380668211728334,
-0.013296966440975666,
0.027770277112722397,
-0.025181515142321587,
0.006698364391922951,
-0... |
<p>Does anyone know how can i perform Geographically Weighted Regression in MATLAB?i am a newbie. also, can someone provide sample in solving GWR?</p> | g65496 | [
0.013435077853500843,
-0.010023743845522404,
0.01431070826947689,
-0.03074275702238083,
0.023201188072562218,
0.05662551894783974,
-0.00615253672003746,
0.054603561758995056,
-0.07319140434265137,
0.012928563170135021,
0.00853654183447361,
0.017696432769298553,
0.05508264899253845,
0.00050... |
<p>The wiki discusses the problems that arise when <a href="http://en.wikipedia.org/wiki/Multicollinearity">multicollinearity</a> is an issue in linear regression. The basic problem is multicollinearity results in unstable parameter estimates which makes it very difficult to assess the effect of independent variables o... | g49678 | [
0.017110345885157585,
0.03177367523312569,
-0.014936316758394241,
-0.014231834560632706,
0.05006665363907814,
-0.03959805145859718,
-0.023880405351519585,
0.05105539411306381,
-0.05023455619812012,
0.005516699980944395,
-0.011308787390589714,
-0.007081757765263319,
0.003782876068726182,
0.... |
<p>I would like to compare the curvature of two response surfaces, each of the form:</p>
<p>binomial ~ continuous variables1-5</p>
<p>I think it would be appropriate to use the effective degrees of freedom of a thin-plate spline fit to the data with generalized cross-validation as an estimate of the curvature. Is thi... | g24089 | [
0.024765342473983765,
-0.014632748439908028,
-0.004827140364795923,
0.008274596184492111,
0.008528760634362698,
0.02282216213643551,
0.08627437800168991,
-0.0052623082883656025,
-0.02348403073847294,
0.007883860729634762,
0.013199972920119762,
-0.006599876563996077,
0.05616544187068939,
-0... |
<p>Can anyone tell me if logistic correction is the best method to correct the probability of gradient boosting machine? If so, how can I do it?</p> | g44101 | [
0.020139163359999657,
-0.01061063352972269,
0.03403659909963608,
-0.011826349422335625,
0.03915850818157196,
0.0023142395075410604,
0.017690384760499,
0.0278968196362257,
-0.07365050911903381,
0.06126020848751068,
0.01284346729516983,
0.05231688171625137,
0.06323950737714767,
0.07166433334... |
<pre><code>set.seed(11)
a = runif (12)
b = rep(c(1,2,3),4)
summary(lm(a~b))$coeff
summary(lm(a~b-1))$coeff
</code></pre>
<p>What does a p.value for the intercept means ?</p>
<p>What differences makes the second formula ?</p>
<p>Why is the p.value lower and the R squared higher in the second formula ?</p>
<p>What do... | g49310 | [
0.017581181600689888,
0.005504237487912178,
-0.04159383848309517,
-0.03731044754385948,
0.06255202740430832,
-0.02480245940387249,
0.0764283761382103,
0.029098857194185257,
-0.09828750044107437,
-0.01404115092009306,
-0.08557267487049103,
0.05522143468260765,
0.016580641269683838,
-0.01015... |
<p>For a binomial GLM, both the probability and the number of trials are important for each data entry. Using the <code>glm</code> fucntion in R, how do I specify them separately and explicitly?</p>
<p>Previously, when using <code>glm</code> for the binomial family, I used <code>glm(cbind(V4, V5) ~ V1 + V2 + V3, famil... | g65497 | [
0.016151538118720055,
-0.012471351772546768,
-0.017555320635437965,
0.004995663650333881,
0.032779593020677567,
-0.044478755444288254,
0.03002951666712761,
-0.01518726721405983,
-0.06886950880289078,
-0.033494774252176285,
-0.03875277563929558,
0.012492496520280838,
0.05081323906779289,
0.... |
<p>What does mean by the "the cumulative frequency in the form of probits" (see diagram)? How to use this methodology when one has only the Ratio and group information. I wonder how to compute these probits for the cumulative frequencies (preferably in R). Thanks in advance for your help and time.</p>
<p><img src="ht... | g65498 | [
0.01492056529968977,
-0.037020061165094376,
-0.0019917450845241547,
-0.031032046303153038,
-0.0017840559594333172,
-0.02942105568945408,
0.05294731631875038,
0.012216799892485142,
-0.05529098957777023,
-0.032986026257276535,
0.03336070105433464,
-0.035509783774614334,
0.05109589174389839,
... |
<p>I have a setting of a continuous response vector of expression Y of length N, that has also a case/control label for each measurement. In addition, I have an X matrix of features, NxP. I would like to learn (e.g., using linear regression) and quantify the contribution of each feature to the magnitude of differential... | g65499 | [
0.01719949208199978,
-0.07916059345006943,
-0.03228353336453438,
-0.024575520306825638,
0.04520368203520775,
-0.014910438098013401,
0.05254287272691727,
0.00024191920238081366,
-0.01293104887008667,
-0.02553371526300907,
0.029935413971543312,
0.01894182711839676,
0.06856857985258102,
0.041... |
<p>My data is described here <a href="http://stats.stackexchange.com/questions/97165/what-can-cause-a-error-model-is-singular-error-in-aov-when-fitting-a-repeate">What can cause a "Error() model is singular error" in aov when fitting a repeated measures ANOVA?</a></p>
<p>I am trying to see the effect of an i... | g24094 | [
-0.0020311472471803427,
-0.04110357165336609,
-0.01657206565141678,
-0.011917033232748508,
0.029514869675040245,
0.04411448538303375,
0.05749061331152916,
0.012427289970219135,
-0.01865294575691223,
-0.008952086791396141,
-0.03693058341741562,
0.016426686197519302,
0.03169062361121178,
0.0... |
<p>I am implementing code to compute the two-sided Fisher exact test of 2x2 contingency tables in C. I read that R's implementation is not the most efficient way to calculate the p-value for a two-sided test. My first question is, how is this implemented? Wikipedia states</p>
<pre><code>"An approach used by the fisher... | g65500 | [
0.0188656784594059,
-0.046102944761514664,
-0.001767753972671926,
-0.02605096809566021,
0.02801496908068657,
-0.055086370557546616,
0.04574192687869072,
0.055187247693538666,
-0.10523326694965363,
-0.017345109954476357,
-0.03561153635382652,
0.04117549583315849,
0.032776061445474625,
0.025... |
<p>Consider the following situation. I want to model individual tree stem volumes based on the explanatory variables "tree height" and "diameter" (Diameter at breast height - 1.3 m - DBH).</p>
<p>In the field, diameters are easier to measure than heights. So, it is common to collect more diameter observations than hei... | g65501 | [
0.005792257841676474,
-0.0006838066619820893,
-0.006534930784255266,
-0.045972444117069244,
-0.006324743386358023,
-0.040367916226387024,
0.02601321041584015,
-0.012158272787928581,
-0.01390588004142046,
-0.009264414198696613,
0.001331179984845221,
-0.017729254439473152,
0.07334214448928833,... |
<p>I have a dataset with a few million rows and ~100 columns.
I would like to detect about 1% of the examples in the dataset, which belong to a common class. I have a minimum precision constraint, but due to very asymmetric cost I am not too keen on any particular recall (as long as I am not left with 10 positive match... | g65502 | [
0.01761300303041935,
-0.008864871226251125,
-0.005667936056852341,
-0.04221627861261368,
-0.0015635937452316284,
-0.08146707713603973,
0.04180823266506195,
0.002478142501786351,
-0.024746989831328392,
0.012577679939568043,
0.0225291196256876,
0.004699396435171366,
0.07026007771492004,
0.01... |
<p>I understand how to test programs that are either right or wrong. But what if permissible some inaccuracy? How to distinguish a bug in the implementation of bad classifier? Naive solution (baseline)? But it seems that it will help to find the only really bad solution. I think you understand what I mean. </p>
<p>Wha... | g24097 | [
0.0608828142285347,
-0.04271728917956352,
0.02334742806851864,
-0.01877673715353012,
0.03291836008429527,
-0.00002469777246005833,
-0.027152344584465027,
0.029254259541630745,
-0.018506383523344994,
-0.028788946568965912,
0.011501382105052471,
0.05772596597671509,
0.03250815346837044,
0.06... |
<p>Suppose I've data for 100 individuals for 5 variables, say Var1, Var2,...Var5. I run the cluster analysis using these 5 variables on these 100 rows & got 3 clusters. Now, I want to differentiate these 3 clusters based on 5 variables. That is, which among these 5 variables has been loaded more for which cluster, ... | g65503 | [
0.016709858551621437,
-0.05817604437470436,
0.002428138628602028,
-0.0611991249024868,
0.012032038532197475,
-0.05153065547347069,
0.005703495815396309,
0.00035672044032253325,
-0.032433100044727325,
-0.00901362020522356,
0.013303847052156925,
0.027335669845342636,
0.052005209028720856,
0.... |
<p>I am a thesis student. I conducted an experiment on three different schools. I took a class from each school and assumed that they are one group. I took one group and considered it as a control group. I used paired t test.
The reader in my defense considered that I can't assume that students from each school as on... | g65504 | [
-0.01773558370769024,
-0.03043842501938343,
0.0037953099235892296,
-0.036866072565317154,
0.05600433051586151,
0.0341486819088459,
0.06321633607149124,
0.03186511620879173,
0.004483007825911045,
-0.0018119345186278224,
0.09033799171447754,
0.013751933351159096,
-0.013085544109344482,
0.040... |
<p>To make clear what I want to ask, I want to begin with the negative binomial distribution. The first two moments are $E(y)=\mu$ with variance $Var(y)=\mu+\mu^2/k$. When we solve the scorefunction of the log-likelihood with an iterationalgorithm, we get an estimator for $\widehat{\mu}$ (because of the estimator of $\... | g65505 | [
-0.02438170462846756,
-0.015567503869533539,
-0.0004479071358218789,
-0.013438363559544086,
0.04774139076471329,
-0.017229123041033745,
-0.008675175718963146,
0.03385951742529869,
-0.0900542140007019,
0.021712351590394974,
-0.08490865677595139,
0.013871299102902412,
0.011053072288632393,
0... |
<p>I'm interested in an estimator of the standard deviation in a Poisson regression. So the variance is </p>
<p>$$Var(y)=\phi\cdot V(\mu)$$</p>
<p>where $\phi=1$ and $V(\mu)=\mu$. So the variance should be $Var(y)=V(\mu)=\mu$. (I'm just interested in how the variance should be, so if overdispersion occurs ($\widehat{... | g65506 | [
0.030681133270263672,
-0.024620264768600464,
0.0005801569204777479,
-0.03298074007034302,
-0.01618298515677452,
0.011618977412581444,
-0.013438282534480095,
0.015645131468772888,
-0.01633913815021515,
-0.04450712725520134,
-0.007317892275750637,
-0.00610800227150321,
-0.0378413163125515,
-... |
<p>I plot something to make a point to myself or someone else. Usually a question starts this process, and often the person asking hopes for a particular answer.</p>
<p>How can I learn interesting things about the data in a less biased way?</p>
<p>Right now I'm roughly following this method:</p>
<ol>
<li>summary st... | g24103 | [
0.003990259952843189,
0.007657104171812534,
-0.0069190277718007565,
-0.05510833486914635,
-0.007925963960587978,
0.016294077038764954,
0.02191288396716118,
-0.029233641922473907,
-0.002957955002784729,
-0.04203252121806145,
0.0773768275976181,
0.02957170084118843,
0.08712377399206161,
0.04... |
<p>Is it possible to perform a statistical test to determine if one classifier is better than the other using only the confusion matrices of these classifiers? </p>
<p>What about the average accuracies from k-fold cross validation?</p>
<p>I have a number confusion matrices and average accuracy for classifiers obtain... | g65507 | [
0.026827216148376465,
-0.03282255306839943,
0.030731171369552612,
0.029545169323682785,
0.043684374541044235,
-0.054514601826667786,
0.030403606593608856,
0.04058513790369034,
-0.033317930996418,
0.01744547113776207,
0.08412154018878937,
0.02915315516293049,
0.04195748269557953,
-0.0211541... |
<p>In Bayesian Inference the following notation is quite common:</p>
<p>$P(H|D) = \frac{P(D|H)P(H)}{P(D)}$</p>
<p>where $D$ is data and $H$ is hypothesis. Moreover $P(D)$ is represented as total probability.</p>
<p>$P(D) = \sum P(D|H)P(H)dH$</p>
<p>However in my opinion notation seems to be quite sloppy. It is conf... | g65508 | [
0.02478521317243576,
-0.024395830929279327,
0.003061567200347781,
-0.041029978543519974,
-0.020604794844985008,
-0.03289554640650749,
0.06201007962226868,
0.07079844176769257,
-0.019436970353126526,
-0.02255195938050747,
0.03428691253066063,
-0.017370466142892838,
0.03703128546476364,
0.04... |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.