question stringlengths 37 38.8k | group_id stringlengths 2 6 | sentence_embeddings listlengths 768 768 |
|---|---|---|
<p>I've got back reviews for a paper I've submitted, with the following problem.</p>
<p>I have two logistic regression models, say y ~ A, and y ~ A + B, where B is a factor with several levels. I have performed a likelihood ratio test between them, and it is highly significant. My goal is to show that B has some indep... | g58467 | [
0.007293504662811756,
-0.020503824576735497,
-0.012955676764249802,
-0.05533348768949509,
0.001981798792257905,
-0.02596859633922577,
-0.023046432062983513,
0.018659286201000214,
-0.009847569279372692,
0.015178493224084377,
0.05394965410232544,
0.019110068678855896,
0.05490102618932724,
0.... |
<p>Suppose $\boldsymbol \beta \in \mathbb{R}^k$ is a vector of coefficients for a generalized linear model with $g \left[ E(Y|X) \right] = X\beta$ for a link function $g$ and I wish to test the composite hypothesis
$H_0: \beta_k =0$ versus $H_1: \beta_k \neq 0$
where the other parameters $\beta_{-k}$ are nuisance param... | g58468 | [
-0.02451566979289055,
-0.02201833762228489,
0.004847809672355652,
0.016053522005677223,
0.03756335377693176,
-0.01792352832853794,
0.025638723745942116,
-0.0024404646828770638,
-0.030986877158284187,
0.025283927097916603,
-0.026447845622897148,
0.014532268047332764,
0.002442925935611129,
0... |
<p>I'm trying to identify people by determining if a data sample matches a set of existing samples (assume DNA if it helps). In addition to the samples I have a function which gives a probability that two samples represent a match. That is, I have:</p>
<ul>
<li>$X$ is a new sample I've taken from a person</li>
<li>$... | g58469 | [
0.01503558550029993,
-0.06101500988006592,
-0.0054003652185201645,
-0.01898873783648014,
-0.02331797033548355,
0.020067522302269936,
-0.011544573120772839,
0.040954288095235825,
-0.0540132001042366,
-0.049958065152168274,
0.007733404636383057,
-0.023425959050655365,
0.03819694742560387,
-0... |
<p>When trying to model a latent growth model in lavaan and AMOS respectively, they seem to approach the time spacing of the slope estimates differently. Lavaan defaults to whole numbers increasing by time period: 0, 1, 2, 3, ..., while AMOS seems to default to fractions: 0, 0.11, 0.22, 0.33, ... . What differences in ... | g58470 | [
0.07096191495656967,
0.03638689965009689,
-0.0024410828482359648,
-0.026306670159101486,
0.04095090925693512,
0.013900095596909523,
0.07359915226697922,
-0.030880646780133247,
-0.03284703195095062,
-0.04235247150063515,
-0.029229026287794113,
-0.027880946174263954,
0.06897246837615967,
0.0... |
<p>I will construct an example to demonstrate something I am working on to solve a real-world problem. Pretend we are in a zoo and this zoo contains 5 enclosures of different animals. Enclosure A contains 3 Ants, enclosure B contains 3 Baboons, enclosure C contains 2 Cats, enclosure D contains 4 Dogs, enclosure E conta... | g58471 | [
-0.008036571554839611,
0.04250263795256615,
0.018748611211776733,
-0.03045382723212242,
-0.01241008285433054,
-0.04920799285173416,
0.02874661423265934,
-0.0067458609119057655,
-0.020819904282689095,
0.032337769865989685,
-0.044626280665397644,
0.022050492465496063,
0.00979352742433548,
-0... |
<p>I have a series which takes values as <code>1</code>,<code>2</code> and <code>3</code>. It also has some <code>NA</code> values. The following is a sample from the series. </p>
<pre><code>series1 <- c(1, 1, 2, 1, 1, 1, 1, 2, 2, 2, NA, NA, NA, 3, 2, 2, 1, 1, 1,1)
</code></pre>
<p>My question is how should I go a... | g48750 | [
0.04556156322360039,
-0.02999311126768589,
0.029040468856692314,
-0.06720545142889023,
-0.024734748527407646,
0.02185080014169216,
0.013642188161611557,
0.04820876941084862,
-0.05298168584704399,
0.007586633786559105,
0.0026498250663280487,
0.022288620471954346,
0.015067430213093758,
0.004... |
<p>I recently ran into two problems:</p>
<ol>
<li><p>given a rand() function that generates 0 and 1 with 50% probability respectively (binary outcome), how to write some code to generate 1 with 90% of the chance and 0 with 10%? </p></li>
<li><p>There is a society where people will NOT stop having babies until they hav... | g49530 | [
-0.01052464172244072,
0.03707676753401756,
0.004445080179721117,
-0.057438887655735016,
0.01398889347910881,
-0.002740981290116906,
0.02615458332002163,
0.024890266358852386,
-0.04561823606491089,
-0.02678852342069149,
-0.022659704089164734,
-0.017756588757038116,
0.04020168259739876,
0.02... |
<p>I am working with public use microdata measuring educational attainment. I want to calculate the percentage of the population older than 25. I am merely unaware of how to use my individual weights when calculating this, or if I even have to.</p>
<p>I am wondering if using weights is necessary, and if so, can I use ... | g13562 | [
-0.046121302992105484,
-0.001603010925464332,
-0.009857509285211563,
-0.026278316974639893,
0.010246044024825096,
0.052324000746011734,
0.03566537797451019,
0.008295818231999874,
-0.060310348868370056,
-0.0023121547419577837,
-0.03186335414648056,
-0.0026568961329758167,
0.04226742312312126,... |
<p>I recently ran into two problems:</p>
<ol>
<li><p>given a rand() function that generates 0 and 1 with 50% probability respectively (binary outcome), how to write some code to generate 1 with 90% of the chance and 0 with 10%?</p></li>
<li><p>There is a society where people will NOT stop having babies until they have... | g49530 | [
0.005795888137072325,
0.03331983461976051,
-0.007603762671351433,
-0.05200891196727753,
0.017380213364958763,
-0.019555456936359406,
0.029887570068240166,
0.008906564675271511,
-0.02532934956252575,
-0.02523844502866268,
-0.024264708161354065,
0.013872431591153145,
0.04419068247079849,
0.0... |
<p>Is there a strategy for choosing the number of trees in a GBM? Specifically, the <code>ntrees</code> argument in <code>R</code>'s <code>gbm</code> function.</p>
<p>I don't see why you shouldn't set <code>ntrees</code> to the highest reasonable value. I've noticed that a larger number of trees clearly reduces the va... | g58472 | [
-0.01827734149992466,
0.03826649859547615,
0.0173945315182209,
-0.029493845999240875,
0.019098825752735138,
-0.05483557656407356,
0.0004066840629093349,
0.02637663297355175,
-0.06385418772697449,
0.047346070408821106,
0.020192861557006836,
0.00007103451935108751,
-0.020452672615647316,
0.0... |
<p>I want to calculate the standard errors of a fitted hyperbolic distribution.</p>
<p>In my notation the density is given by
\begin{align*}
H(l;\alpha,\beta,\mu,\delta)&=\frac{\sqrt{\alpha^2-\beta^2}}{2\alpha \delta K_1 (\delta\sqrt{\alpha^2-\beta^2})} exp\left(-\alpha\sqrt{\delta^2+(l-\mu)^2}+\beta(l-\mu)\right)... | g58473 | [
0.06010282412171364,
-0.04997463524341583,
-0.011693152599036694,
0.013065550476312637,
0.04537281394004822,
0.005178074352443218,
0.05505707487463951,
0.025909189134836197,
-0.08456473797559738,
-0.011787627823650837,
-0.015502428635954857,
0.0049372282810509205,
0.04040592163801193,
0.04... |
<p>Let $Y=\left[Y_1, Y_2, \dots, Y_n\right]$ be a sequence of exchangeable, approximately normal random variables. Let $X_1=\left[X_{11}, X_{12}, \dots, X_{1n}\right]$ and $X_2=\left[X_{21}, X_{22}, \dots, X_{2n}\right]$ be two predictions for the $Y$, i.e. $(X_{1i}, Y_i)$ and $(X_{2i}, Y_i)$ are ordered prediction-re... | g58474 | [
-0.032845254987478256,
0.013403050601482391,
0.0023934084456413984,
0.015096486546099186,
-0.025030052289366722,
-0.05972222611308098,
0.06208469718694687,
-0.01457926630973816,
-0.0030156534630805254,
0.007478152401745319,
0.023412898182868958,
0.04510130360722542,
-0.012906486168503761,
... |
<p>I would like to compare 3 different treatments (no one treatment is considered the placebo, and these are not randomized control trials) from multiple studies in a meta-analysis. I am using the software called "Review Manager" from the Cochrane society, and I am wondering if what I am doing is correct or not:</p>
<... | g13566 | [
0.013241948559880257,
-0.07255932688713074,
-0.025789810344576836,
-0.04362935200333595,
-0.007341742981225252,
-0.02935633435845375,
0.010645859874784946,
-0.011423613876104355,
-0.03289007768034935,
-0.0018000757554545999,
0.031189290806651115,
-0.008997873403131962,
0.043049369007349014,
... |
<p>I have survey data for thousands of individuals from hundreds of towns. I want to identify factors underlying certain characteristics at the town level and the individual level. The individual level is straightforward. But I'm less clear on how to proceed with the town-level data.</p>
<p>I am considering two approa... | g13567 | [
-0.02292182296514511,
0.010761317797005177,
0.005681460723280907,
-0.09555956721305847,
0.0010868130484595895,
-0.03781246766448021,
0.03058142587542534,
-0.048944514244794846,
-0.03888969495892525,
0.038780514150857925,
0.024798475205898285,
-0.006142974365502596,
0.03462255001068115,
-0.... |
<p>Suppose that a categorical variable $X$ can take three values: $0$,$1$ or $2$. If we run a Cox proportional hazards model and get an estimate of $\beta_1$, how would we interpret this? So we get:</p>
<p>$$\log[\text{HR}]= \log[h_{0}(t)]+ \beta_{1}X$$</p>
<p>Would $\exp(\beta_1)$ give the hazard ratio between $X=2$... | g13568 | [
0.03920666500926018,
-0.032654449343681335,
-0.022220753133296967,
-0.012906127609312534,
0.08148244023323059,
0.010970622301101685,
-0.05149831622838974,
0.024931438267230988,
-0.07714062184095383,
-0.004482636693865061,
-0.04961423948407173,
0.025181015953421593,
0.04559905081987381,
-0.... |
<p>I have performed classification using multiple classifiers for a 2-classes labelled data, and I used 5-fold cross validation. For each fold I calculated tp, tn, fp, and fn. Then I calculated the accuracy, precision, recall and F-score for each test. My question is, when I want to average the results, I took the aver... | g58475 | [
-0.023098384961485863,
-0.056684497743844986,
0.014884012751281261,
-0.04267808422446251,
0.04810118302702904,
-0.038447439670562744,
0.02383291907608509,
0.04318559914827347,
-0.04544113576412201,
0.00497142318636179,
0.028949560597538948,
0.01671471819281578,
0.039197176694869995,
-0.004... |
<p>I need to do a simulation to evaluate an integral of a 3 parameter function, we say $f$, which has a very complicated formula. It is asked to use MCMC method to compute it and implement the Metropolis-Hastings algorithm to generate the values distributed as $f$, and it was suggested to use a 3 variated normal as pro... | g58476 | [
0.056976404041051865,
-0.026805343106389046,
-0.010607263073325157,
-0.043049708008766174,
-0.027521220967173576,
0.01713697426021099,
-0.01983792521059513,
0.03345039114356041,
-0.049288298934698105,
0.05487823858857155,
0.0031038224697113037,
0.029328539967536926,
-0.014148314483463764,
... |
<p>I have a huge matrix (10*10k). I'd like to know if there is a way to find similarities between lines.</p>
<p>Let's give an example of matrix: 4*5</p>
<pre><code>col1 col2 col3 col4
0 0 1 0
2 3 4 5
2 3 2 3
0 0.1 1 0
0 0 1 0
</code></pre>
<p>I'd like to k... | g58477 | [
0.023138923570513725,
-0.022032715380191803,
0.005326437763869762,
-0.03204768896102905,
-0.007640309631824493,
-0.038263946771621704,
0.048264749348163605,
-0.0022862006444483995,
-0.07746962457895279,
-0.02790364809334278,
-0.029434630647301674,
0.012639916501939297,
0.03253814950585365,
... |
<p>I'm trying to estimate performance of an investment account over 20 years. The question is, have I set up the Monte Carlo simulation correctly? I've used Excel. I've assumed 8% average return and 13% volatility and a starting account size of $100,000. </p>
<p>I generate a random return using the function <code>norm... | g13580 | [
0.01514632347971201,
0.026653673499822617,
-0.01385215949267149,
-0.02954171597957611,
-0.01401941291987896,
0.010146298445761204,
0.056332025676965714,
-0.004909321200102568,
-0.016790490597486496,
0.0003587951650843024,
-0.0032542680855840445,
0.03174380213022232,
0.013030534610152245,
-... |
<p>I have a problem calculating confidence intervals from a gamm model. My data looks like this:</p>
<p><img src="http://www.maunz.de/gamm/data.png" alt="data"></p>
<p>As you can see, these are longitudinal data of subjects in groups (Each subject appears only in one group). My gamm model looks like this:</p>
<pre><... | g58478 | [
-0.0104082515463233,
-0.07131940126419067,
-0.015620579943060875,
0.0035644196905195713,
0.004437634721398354,
0.027518797665834427,
0.01106964610517025,
0.019433245062828064,
-0.0463690310716629,
0.015393062494695187,
0.025208203122019768,
0.029520966112613678,
0.06092001870274544,
-0.019... |
<p>Consider Schelling's question about a focal meeting point for NYC in game theory (described in the second paragraph under <strong>Formulation</strong> in the <a href="https://en.wikipedia.org/wiki/Focal_point_(game_theory)" rel="nofollow">Wikipedia entry</a>). Schelling didn't say how many students he surveyed. How... | g58479 | [
-0.044269196689128876,
0.029258038848638535,
-0.008072352036833763,
-0.008633469231426716,
0.021412305533885956,
0.032665811479091644,
0.02455662377178669,
0.022675396874547005,
0.048968710005283356,
0.0709887444972992,
-0.012987516820430756,
-0.019664457067847252,
0.05505917966365814,
-0.... |
<p>As far as I know, Taylors expansion works for fixed functions. I was wondering why it is justified to use it on the log likelihood. Even if we consider it as a function of only $\theta$, doesn't it have components that change as n increases (like $\sum X_i$ for example) ? Is it really always ok to say something like... | g58480 | [
0.012718727812170982,
-0.030845770612359047,
0.016544286161661148,
-0.03731215000152588,
-0.03715193644165993,
0.007037680130451918,
0.04523620754480362,
0.032209914177656174,
-0.008632147684693336,
-0.015335804782807827,
0.005755439400672913,
0.050322938710451126,
0.042995769530534744,
0.... |
<p>I got nice graphical representation of Machine learning for clustering / classification. </p>
<p><img src="http://i.stack.imgur.com/wroQs.jpg" alt="enter image description here"></p>
<p>Source: <a href="http://link.springer.com/chapter/10.1007%2F978-3-642-10467-1_1" rel="nofollow">Kernel Approaches to Unsupervised... | g127 | [
0.032765716314315796,
-0.02914620190858841,
0.023899206891655922,
-0.01957438513636589,
0.015941357240080833,
-0.020870182663202286,
0.027793390676379204,
0.03507433831691742,
0.004466191865503788,
-0.013427299447357655,
0.04679078981280327,
-0.01927473023533821,
0.08159910887479782,
0.018... |
<p>I'm working on winderosion and the question, if there is a relation between erosive winds and high PM10-concentration (fine dust) as a evidence to eroded dust particles.</p>
<p>I have two different datasets:</p>
<ol>
<li>PM10-Concentration for a certain measuring spot (hourly,
2010-2012) </li>
<li>Meteorological d... | g58481 | [
0.06806221604347229,
-0.06674958020448685,
-0.0004893676959909499,
-0.04288257285952568,
0.04514387622475624,
0.00013306316395755857,
0.03847304731607437,
-0.01820535585284233,
-0.03606756031513214,
-0.008813291788101196,
-0.014974072575569153,
0.03726941719651222,
0.048545993864536285,
0.... |
<p>Is there an R random forest implementation that works well with very sparse data? I have thousands or millions of boolean input variables, but only hundreds or so will be TRUE for any given example.</p>
<p>I'm relatively new to R and noticed that there is a 'Matrix' package for dealing with sparse data, but the sta... | g58482 | [
0.03634101152420044,
-0.03681250289082527,
0.003035094356164336,
-0.047217972576618195,
-0.05683339014649391,
-0.08544619381427765,
-0.004378849640488625,
0.031896501779556274,
0.005846395157277584,
-0.00622516730800271,
-0.01199846900999546,
0.008486570790410042,
0.0027539099100977182,
-0... |
<p>Which article should I reference as a source of the following claim?:</p>
<p><em>The $\chi^2$ test is not recommended when too many sparsely populated bins exist in a given histogram.</em></p>
<p>Please rephrase the above sentence if it is not clear.</p>
<p><a href="http://goo.gl/GVlSO" rel="nofollow">This articl... | g42537 | [
0.054363008588552475,
0.05966878682374954,
-0.003814051393419504,
-0.0737326368689537,
0.03162670508027077,
-0.02259289100766182,
0.051796045154333115,
0.010632970370352268,
-0.029221417382359505,
-0.035037215799093246,
0.005144011229276657,
0.012566794641315937,
0.02645101770758629,
0.047... |
<p>This question was originally asked by a colleague with regards to calculation of AIC for a non-linear mixed effects model (<code>nlme</code>) <em>where off-diagonal elements of the covariance matrix are estimated</em>. The equations for AIC (from <a href="http://en.wikipedia.org/wiki/Akaike_information_criterion" re... | g58483 | [
-0.01022952888160944,
-0.04830038174986839,
0.005164034198969603,
-0.03907296806573868,
-0.005608187057077885,
0.027275454252958298,
0.0352310873568058,
0.042325206100940704,
-0.0030783317051827908,
-0.013020146638154984,
0.03438786044716835,
0.015302972868084908,
0.056109532713890076,
0.0... |
<p>I've been playing around with fitting nonlinear models using rjags. Specifically 3 and 4 parameter sigmoid curves, e.g., </p>
<pre><code>upAsym + (y0 - upAsym)/ (1 + (x[r]/midPoint)^slope))
</code></pre>
<p>I've noticed that good parameter estimates (+- 95% HDIs) are highly dependent upon having tightly constrain... | g43467 | [
0.001188587280921638,
-0.04854142665863037,
-0.007563916500657797,
-0.013259581290185452,
-0.027444753795862198,
-0.04551323875784874,
0.03981954604387283,
0.0038758243899792433,
-0.04213985800743103,
0.010938892140984535,
0.019787203520536423,
-0.01582798734307289,
0.04852712154388428,
0.... |
<p>I have two dataset that i want to compare.
each dataset contain the weight of 10 different person measured for 3 different day.</p>
<p>I am interested in measuring the probabily that the two sample originate from the same population.</p>
<p>People seem to suggest doing a Kolmogorov-Smirnov test but i need a measu... | g58484 | [
0.03493739664554596,
-0.05695836618542671,
-0.029479024931788445,
-0.0063497512601315975,
-0.036645520478487015,
0.05047192424535751,
0.012448291294276714,
0.05611526966094971,
-0.03838787600398064,
-0.012203481048345566,
0.03600655868649483,
-0.050954680889844894,
0.08547452837228775,
0.0... |
<p>Background: a friend of mine makes a hobby (as I imagine many do) of trying to predict hockey playoff outcomes. He tries to guess the winning team in each matchup, and the number of games needed to win (for anyone unfamiliar with NHL hockey a series is decided by a best of 7). His record this year after 3 rounds of ... | g58485 | [
0.000958564574830234,
0.027193667367100716,
-0.005574357230216265,
-0.005896576680243015,
-0.02257680892944336,
-0.07549306750297546,
0.023510711267590523,
-0.020204849541187286,
-0.013124436140060425,
-0.022265229374170303,
-0.021368972957134247,
0.039427250623703,
0.03129636496305466,
0.... |
<p>I think I have understood why $E[E(X_1X_2|X_1)]=E[X_1E(X_2|X_1)]$; so your support would really help me being more convinced.</p>
<p>Do we take out the $X_1$ from the inner expected value because it is calculated with respect to the marginal distribution of $X_2$? And why is it calculated with respect to the margin... | g58486 | [
0.0037058524321764708,
0.010527762584388256,
-0.01567726582288742,
-0.03691483289003372,
-0.022989684715867043,
-0.003509450238198042,
0.07104598730802536,
0.08572348952293396,
-0.029143113642930984,
-0.003139435313642025,
-0.01674940437078476,
0.03887081891298294,
0.014284687116742134,
0.... |
<p>I need to do a markov blanket filter for feature selection for highly unbalanced datasets.</p>
<p>There are popular algorithms to do this? I need to understand the algorithm behind this.</p>
<p>From what I understand if I have the feature Fi and I found the markov blanket Mi I can filter all feature in Mi because ... | g13589 | [
0.029346924275159836,
-0.0024068965576589108,
0.008359638042747974,
0.00016422237968072295,
0.014529986307024956,
-0.0683683529496193,
0.004415065515786409,
0.048670444637537,
-0.00713530695065856,
-0.01129535399377346,
-0.033302828669548035,
0.043579891324043274,
0.040291979908943176,
0.0... |
<p>I have two doubt, one about theory and one about practical problem.</p>
<p><strong>First i have not full understand</strong> how to work a bayesian network with continuous values.
I have learn that i can approximate P(A) (the probability of node A) with a Gaussian Distribution. But i have a dataset, mean and vari... | g424 | [
0.022053688764572144,
-0.006077631842344999,
-0.012476206757128239,
-0.020841069519519806,
-0.028320109471678734,
-0.00656755780801177,
-0.05522016063332558,
0.00975782796740532,
-0.07218990474939346,
-0.060620442032814026,
-0.002420915523543954,
-0.0090870326384902,
0.05685359239578247,
-... |
<p>The probability density function I have is as following:</p>
<p><img src="http://i.stack.imgur.com/vTfFe.gif" alt="enter image description here"> </p>
<p>Now, I want to rewrite the cumulative probability function bellow into R.</p>
<p><img src="http://i.stack.imgur.com/HA6e5.gif" alt="enter image description here... | g58487 | [
0.007886647246778011,
-0.0909760370850563,
-0.008547154255211353,
-0.01661771908402443,
0.012762326747179031,
-0.020377932116389275,
0.03712010011076927,
0.02504642866551876,
-0.06646759808063507,
0.035086456686258316,
-0.011644028127193451,
-0.00592936621978879,
0.023338617756962776,
-0.0... |
<p>I am comparing 2 separate datasets with the Mann-Whitney U test. I am analyzing three separate parameters present in both datasets and want to know which parameter gives greatest separation between the two datasets. The lower the P value, the greater the separation, right? As N1 and N2 are the same for all three tes... | g4275 | [
0.03561004623770714,
-0.035875800997018814,
-0.014041760936379433,
-0.02856372855603695,
0.0369357094168663,
-0.014336944557726383,
0.012281638570129871,
0.028488727286458015,
-0.06278989464044571,
-0.018585829064249992,
-0.01179883349686861,
-0.02200649306178093,
0.033517222851514816,
0.0... |
<p>A Gaussian process gives a probability distribution over functions that pass through the data points. Is there a way to parameterize the Gaussian process to give a probability distribution over closed curves instead of functions? Can the same approach be generalized to give a distribution over surfaces without bound... | g58488 | [
0.08517613261938095,
-0.036588747054338455,
-0.003991259727627039,
-0.01191375870257616,
-0.02979397587478161,
0.07175017148256302,
0.03395898640155792,
-0.0014370321296155453,
-0.02008197270333767,
-0.044862352311611176,
0.04344979301095009,
0.033694468438625336,
0.08849222958087921,
0.00... |
<p>I have a data set with 2 different curves in a .csv file. Both curves are a sum of Gaussian curves and I'd like to be able to decompose these curves into their substituent addends:</p>
<pre><code>curve1,curve2,x
274519,242446,0
250313,220161,1
233884,207918,2
223944,198910,3
213773,187065,4
198681,171146,5
186277,1... | g58489 | [
0.007529228925704956,
-0.02636593207716942,
-0.00959632359445095,
-0.07578344643115997,
0.0321226641535759,
-0.05670399218797684,
-0.0034102583304047585,
-0.007386184763163328,
-0.04680095985531807,
-0.028448212891817093,
-0.048359569162130356,
0.0307327713817358,
0.03341591730713844,
-0.0... |
<p>I'm doing principal components analysis (PCA) on quite a bit of data (3000 variables, 100079 data points). I'm doing this mostly for fun; data analysis is not my day job.</p>
<p>Normally, to do a PCA I would calculate the covariance matrix and then find its eigenvectors and corresponding eigenvalues. I understand v... | g13590 | [
0.04608601704239845,
-0.026732051745057106,
-0.004256375599652529,
-0.06286731362342834,
0.013402535580098629,
0.005789370741695166,
0.07796797156333923,
0.05963839590549469,
0.003918736707419157,
-0.0194423645734787,
0.01916554570198059,
-0.008472478948533535,
0.04536491259932518,
0.03205... |
<p>If so, why? If not, why not?</p>
<p>I'm thinking of an ANOVA context, but if the answer changes depending on context I would also be interested to know why that is.</p> | g58490 | [
0.011341238394379616,
0.06318216025829315,
0.04390712454915047,
0.034876711666584015,
-0.0013393750414252281,
-0.005566863343119621,
-0.0036651790142059326,
-0.0031242615077644587,
-0.008183966390788555,
-0.03280610591173172,
0.015728725120425224,
0.021954454481601715,
0.015990672633051872,
... |
<p>I work in an M2M engineering startup and the engineering team have been conceptualizing a complex event processor and want to build "alerts" when an event might occur.</p>
<p>The initial plan was to build a rules engine, but I have a feeling the rule engine could grow to an unwieldy size making manual maintenance d... | g348 | [
-0.021768227219581604,
0.015573651529848576,
-0.012437275610864162,
-0.040829066187143326,
-0.017231224104762077,
-0.1472894847393036,
-0.007611644919961691,
0.04244998097419739,
-0.05262663960456848,
-0.036174871027469635,
0.028191452845931053,
0.011835586279630661,
0.060163285583257675,
... |
<p>Can anyone advise me on a good library in <strong>Python</strong>, <strong>Java</strong> or <strong>R</strong> for constructing an infinite Bayesian mixture model? Other options are also welcome.</p>
<p>Thanks.</p> | g13591 | [
-0.04229254275560379,
-0.037069860845804214,
0.027139708399772644,
-0.053882990032434464,
-0.024358512833714485,
0.004234830848872662,
-0.03179572522640228,
0.032047025859355927,
-0.00970869418233633,
-0.03212764859199524,
0.032580211758613586,
-0.05999965965747833,
0.026741517707705498,
0... |
<p>We know that there are searching algorithms with time complexity O(lgn) </p>
<p>but is there any sorting algorithm with time complexity O(lgn)?</p> | g58491 | [
0.04146389290690422,
0.07399933785200119,
0.014153843745589256,
-0.05613819137215614,
-0.05619024112820625,
-0.03210177272558212,
-0.040245573967695236,
-0.024531926959753036,
-0.02804635465145111,
0.06894635409116745,
-0.009392830543220043,
-0.019963763654232025,
-0.0214909166097641,
0.01... |
<p>I have a three point Likert scale question: </p>
<pre><code>How happy are you?
1= low levels of happiness
2= medium levels
3= high levels
</code></pre>
<p>I want to do multiple linear regression on the variable. I am making the assumption that that it has the same difference between low and medium ... | g13592 | [
0.02280333824455738,
-0.030129414051771164,
-0.011273257434368134,
-0.052842769771814346,
-0.05932290107011795,
0.05638279393315315,
-0.015308527275919914,
0.009784102439880371,
-0.030479175969958305,
-0.0313006192445755,
0.0075029912404716015,
0.0393061526119709,
-0.03522149473428726,
0.0... |
<p>I have seen many reports which include (say) 6 scatter plots in one big table like format. Each scatter plot shows the relationship between two different variables. For example, one may show the relationship between income and expenditure and another may show the relationship between mortgage payment and holiday tak... | g58492 | [
0.04736649617552757,
0.015268710441887379,
-0.018961219117045403,
-0.04806825891137123,
-0.04168206825852394,
-0.024417825043201447,
-0.042024705559015274,
0.013653283938765526,
0.021385034546256065,
-0.06967850029468536,
0.03703823685646057,
-0.019194135442376137,
0.06576059758663177,
-0.... |
<p>I'm using a 1.6M tweet corpus to train a naive bayes sentiment engine. </p>
<p>I am trying to "compute the entropy of a probability distribution of the appearance of an n-gram in different datasets". My two data sets are n-grams constructed from a positive corpus & negative corpus, and I want to remove any comm... | g42556 | [
-0.009263169951736927,
0.001597211230546236,
0.005525217857211828,
-0.07003507018089294,
-0.042658720165491104,
-0.07171718776226044,
0.01603531278669834,
0.07704774290323257,
-0.07002472132444382,
0.011578486301004887,
0.012916363775730133,
0.0255203265696764,
0.024930309504270554,
-0.017... |
<p>I have a data set in form of a csv file. This data set contains profiles of different candidates standing for election in a constituency. The columns present in the csv file are:</p>
<p>Candidate, Constituency, States, Party, Criminal Case, Education, Graduate, Total Assets, Serious Charges, Female Win, Male Electo... | g58493 | [
0.00620737811550498,
-0.023457765579223633,
0.028949521481990814,
-0.000702643534168601,
0.010084704495966434,
-0.021256064996123314,
0.04403083771467209,
0.010294410400092602,
-0.08571802079677582,
0.03014395385980606,
-0.00952228158712387,
0.012965747155249119,
0.05548025667667389,
0.005... |
<p>I am interested to know what level of statistics kids are learning in different countries around the world. Could you please suggest data/links that shed light on what is happening in this regards?</p>
<p>I'll start. Israel: The students who are taking advance math study more or less - mean, sd, histogram, normal... | g13601 | [
-0.00717805465683341,
0.061761319637298584,
-0.02085585705935955,
0.009190457873046398,
-0.008306262083351612,
0.04170912131667137,
0.033110782504081726,
0.003935771994292736,
-0.0013238444225862622,
-0.047735635191202164,
0.001513030962087214,
0.004694347269833088,
0.07058630883693695,
-0... |
<p>Should one use regression analysis when all independent variables are binary categorical (0,1) to see their effect on continuous dependent? Some suggest that regression shouldn't be used in this case.</p> | g58494 | [
-0.01727708987891674,
-0.025932684540748596,
0.009188132360577583,
0.022959314286708832,
-0.011963790282607079,
-0.012307753786444664,
0.03134642913937569,
0.049556754529476166,
-0.0432923324406147,
-0.04464806243777275,
0.00482050608843565,
0.026053035631775856,
-0.02177862636744976,
0.05... |
<p>What are important/notable publishing houses for books in statistics?</p>
<p>When I come across a book published at O'Reilly or Springer I imagine its quality will be high. What other notable publishing houses are out there (for statistics books)? Any recommendation on a way to find out? (I'd imagine we could che... | g58495 | [
0.02700819820165634,
0.013673929497599602,
0.0006920900195837021,
-0.027742287144064903,
0.02868424355983734,
0.002775500761345029,
-0.010450165718793869,
0.023218536749482155,
0.002143464284017682,
0.02016374282538891,
0.05604881793260574,
-0.030805986374616623,
0.0493750236928463,
-0.046... |
<p>I have a correlation matrix of security returns whose determinant is zero. (This is a bit surprising since the sample correlation matrix and the corresponding covariance matrix should theoretically be positive definite.)</p>
<p>My hypothesis is that at least one security is linearly dependent on other securities. I... | g58496 | [
0.06090772524476051,
-0.010022002272307873,
0.005106743890792131,
-0.029934193938970566,
0.03453298285603523,
-0.034936558455228806,
0.08467873185873032,
-0.03416120633482933,
-0.05193440616130829,
-0.041466936469078064,
-0.014039385132491589,
0.015247810631990433,
-0.028647765517234802,
0... |
<p>Suppose we have three indicator variables:
$I_1 =1$ or $0$ with some probability
$I_2 =1$ or $0$ with some probability
$J=1$ or $0$ and the value of $J$ depends on $I_1, I_2$. $I_1, I_2$ are independent.</p>
<p>We also have a function $NP$ which is $NP(I_1,I_2,J)$ i.e. it is function of the three indicator variable... | g58497 | [
-0.05701504647731781,
0.006904421374201775,
-0.010662280023097992,
-0.019708728417754173,
-0.007661690469831228,
0.01122282911092043,
0.0003720344393514097,
0.02600545808672905,
-0.029297679662704468,
-0.007275483105331659,
0.018817413598299026,
0.03174315765500069,
0.018836610019207,
-0.0... |
<p>I'm doing least squares estimation on large set of data and I started to wonder whether I should regularize my OLS estimator. My professor told me that this isn't necessary, because the data is overdetermined. Could someone explain to me why? Why isn't regularization required with overdetermined data? </p>
<p>Thnx ... | g58498 | [
0.04851553216576576,
-0.04172500595450401,
-0.00956288818269968,
-0.0713217705488205,
-0.03398922085762024,
-0.03755698725581169,
0.016135884448885918,
0.042376719415187836,
0.029330402612686157,
-0.03676196187734604,
-0.04560394585132599,
0.012833579443395138,
-0.028351908549666405,
-0.00... |
<p>I try to run white test in sas and it return this error message to me.</p>
<pre><code>ERROR: There is no model program. Cannot perform requested tasks
</code></pre>
<p>What is the problem?</p>
<p>Following is the code I use:</p>
<pre><code>proc model data=all;
fit y / white pagan=(1 x1 x2 x3)
out=resid1 ou... | g58499 | [
-0.004538614768534899,
0.015958230942487717,
0.017679616808891296,
-0.045358408242464066,
0.04962528496980667,
0.024944135919213295,
0.03252885490655899,
-0.008830239064991474,
-0.012817219831049442,
-0.06279915571212769,
0.012939193286001682,
-0.009024295955896378,
0.005674016661942005,
0... |
<p><a href="http://stats.stackexchange.com/questions/88980/why-on-average-does-each-bootstrap-sample-contain-roughly-two-thirds-of-observat">Here</a> @gung makes reference to the .632+ rule. A quick Google search doesn't yield an easy to understand answer as to what this rule means and for what purpose it is used. Wo... | g58500 | [
0.002887649228796363,
0.04668203741312027,
0.0006173134897835553,
-0.01937215030193329,
0.026928039267659187,
0.024097653105854988,
0.030711805447936058,
-0.011197230778634548,
-0.03462691605091095,
0.0032887007109820843,
0.02275250293314457,
0.03455771505832672,
0.035435568541288376,
0.00... |
<p>Can we say anything about the dependence of a random variable and a function of a random variable? For example is $X^2$ dependent on $X$?</p> | g58501 | [
0.0015262874076142907,
-0.016796350479125977,
0.004149072337895632,
-0.04726997762918472,
-0.037215955555438995,
0.006829036865383387,
0.002632193500176072,
-0.05938030034303665,
-0.03667965531349182,
-0.013450500555336475,
-0.030587729066610336,
0.04442101716995239,
-0.014851423911750317,
... |
<p>I am not a statistician and I saw a paper in computational PDE, someone argued his error bound for PDE is a good indicator of the PDE's numerical approximation's true error's spatial distribution by using the following way: he had two data sets $\{e\}_{i=1}^N$ and $\{\eta\}_{i=1}^N$ ($i$ is the index of the mesh), a... | g58502 | [
0.0017481946852058172,
-0.001348680118098855,
-0.01632184535264969,
-0.039326366037130356,
-0.0025713953655213118,
0.022330420091748238,
0.06085984781384468,
0.00739309610798955,
-0.061790741980075836,
-0.00842470582574606,
0.037357527762651443,
0.05597425624728203,
0.06659524887800217,
0.... |
<p>I have a rather complicated model that I am testing on a panel data set, containing 3 categorical variables and 3 continuous ones, where I want to specifically test for the interaction effects between the categorical and continuous variables. So far, I have used, in Stata, fixed effect and random effect regression, ... | g13609 | [
-0.022257870063185692,
0.006399752106517553,
0.00008649781375424936,
-0.0003280268283560872,
0.04077773913741112,
-0.04868900403380394,
0.03242902085185051,
0.038850415498018265,
-0.005750350654125214,
-0.03535516932606697,
0.00045856329961679876,
0.007016850635409355,
0.04847189784049988,
... |
<p>I have two paired variables, x and y:</p>
<pre><code>person x y
1 124 100
2 79 94
3 118 105
...
</code></pre>
<p>Here is a scatterplot of the data:</p>
<p><img src="http://i.stack.imgur.com/dz7Pz.png" alt="enter image description here"></p>
<p>I am interested in the corre... | g58503 | [
0.020266620442271233,
0.03212948888540268,
-0.020685579627752304,
-0.046540744602680206,
0.02443844825029373,
-0.0015389162581413984,
0.0019174996996298432,
-0.0450003482401371,
0.0008638787548989058,
-0.061683475971221924,
-0.0387730747461319,
-0.0085642384365201,
0.04669039696455002,
0.0... |
<p>I have a question about something that is probably very basic to statistics but I feel I don't fully understand</p>
<p>I've found that generally it is much harder to get high power (smaller) confidence intervals with binomial data (0,1s)</p>
<p>When I want to calculate the difference between two proportions it is ... | g58504 | [
0.04878898710012436,
-0.007670363411307335,
0.005016636103391647,
0.0024706560652703047,
-0.016917530447244644,
0.007057742681354284,
-0.019262146204710007,
0.0126731488853693,
-0.05093167722225189,
-0.06766960024833679,
0.046712666749954224,
0.0020326445810496807,
-0.017249001190066338,
-... |
<p>I have two questions about selecting ARIMA order(p,d,q).</p>
<p>Assuming that ACF or PACF graph shows spike at lag 4 only<br>
(and there is no spike in any lags),</p>
<p>my question is,</p>
<ol>
<li><p>Do I have to consider MA process rather than AR?<br>
(because there is no spike from lag 1 to lag n-1 sequently... | g13610 | [
0.0049288393929600716,
0.022253934293985367,
-0.02183951623737812,
-0.0016192207112908363,
0.0876498892903328,
-0.06292940676212311,
0.07429945468902588,
0.010454668663442135,
-0.031138887628912926,
0.02593964710831642,
0.007227503694593906,
0.0634743869304657,
0.08026839047670364,
-0.0460... |
<p>For a school research project, I have been instructed to run a large number of tests comparing the proportions of different groups. <a href="http://www.answersresearch.com/proportions.php" rel="nofollow">(Like this, except Statistica will give me a p outright.)</a> The process is laborious and I would like to automa... | g13611 | [
0.023284077644348145,
0.033560555428266525,
-0.017903249710798264,
-0.052071332931518555,
-0.0011756259482353926,
-0.07649895548820496,
0.07808344811201096,
0.016251321882009506,
-0.037127476185560226,
-0.0033828066661953926,
0.03825399652123451,
-0.057815153151750565,
0.09074626117944717,
... |
<p>I want to generate predictions from a fitted logistic regression model that reflect the uncertainty of the model (within a classic frequentist framework). To clarify, my objective is not to characterize the predictive uncertainty as such, but to get a set of reasonable predictions which are fair to the uncertainty a... | g58505 | [
-0.018544066697359085,
-0.04717368260025978,
0.0029949930030852556,
-0.01283324882388115,
-0.03580980747938156,
-0.025933170691132545,
-0.02307307906448841,
0.008282932452857494,
-0.037113089114427567,
-0.03115610033273697,
0.014318251051008701,
0.002137284493073821,
0.06321465224027634,
-... |
<p>I want to apply a Chi-Square test, but I'm not sure whether to include or exclude non-responses. For example, I want to see if GENDER (male, female) is correlated with SATISFACTION on some public policies (Satisfied, Dissatisfied, No answer). Should I use a 2x2 table (excluding No answer) or a 3x2 table (including N... | g4452 | [
0.02649763599038124,
0.047825220972299576,
0.020443715155124664,
-0.05063270777463913,
0.0016746746841818094,
0.0015991067048162222,
0.027862491086125374,
-0.01612098328769207,
0.024691136553883553,
0.009213121607899666,
-0.008697246201336384,
0.038470201194286346,
0.004265884403139353,
0.... |
<p>If you run an ANOVA and find that there are significant interactions, do you then pull the variables out individually and re-run the ANOVA?</p>
<p>I am using Type III. I want to see if there is a difference in survival between 3 groups, but I have to include 3 variables other than group in my model to make sure th... | g58506 | [
-0.02812241204082966,
-0.03140798583626747,
0.009004323743283749,
0.004435718059539795,
0.030454926192760468,
0.04520108550786972,
0.028944239020347595,
0.0261567160487175,
-0.020637765526771545,
0.0013772619422525167,
-0.035932622849941254,
0.004239375237375498,
-0.020070448517799377,
0.0... |
<p>I have binomial data infected/not-infected on individuals of a sample from different years for two different infections.
I have used <code>prop.trend.test</code> to test for trend for each infection.</p>
<p>I want to test if there is a trend in the ratio of infected/not-infected between the two infections. Since a ... | g13615 | [
0.02075887657701969,
-0.03438375145196915,
-0.004532048013061285,
-0.006920313462615013,
-0.008695725351572037,
-0.04497389495372772,
0.033692117780447006,
0.0015413669170811772,
-0.026051687076687813,
0.00006874635437270626,
0.061254072934389114,
0.053775567561388016,
0.009110515005886555,
... |
<p>I am trying to run a Cox regression on a sample 2,000,000 row dataset as follows using only R. This is a direct translation of a PHREG in SAS. The sample is representative of the structure of the original dataset.</p>
<pre><code>##
library(survival)
### Replace 100000 by 2,000,000
test <- data.frame(start=runi... | g425 | [
0.03486429527401924,
-0.0011523414868861437,
-0.014660412445664406,
-0.02859603799879551,
0.02482941374182701,
-0.11896783858537674,
0.0015971502289175987,
0.022932104766368866,
-0.03656141087412834,
-0.010768602602183819,
0.02830108441412449,
0.013395974412560463,
0.10209924727678299,
-0.... |
<p>Assuming a test where <em>p</em> > alpha and <em>n</em> is large enough for power > 95% at effect size <em>d</em>, what is the <em>exact</em> interpretation of the test regarding the relationship between the observed data, the real effect, and power for <em>d</em>?</p>
<p>Some details: if my <em>p</em> is larger th... | g58507 | [
0.012261083349585533,
-0.02745254710316658,
-0.004007585812360048,
-0.05477490648627281,
-0.028463656082749367,
0.01003375742584467,
0.025445381179451942,
0.06395624577999115,
-0.023334026336669922,
-0.04326960816979408,
0.02298676036298275,
-0.0510762594640255,
0.03241722658276558,
0.0396... |
<p>Do both my independent and independent variable have to be normally distributed to run a linear regression? My dependent variable is normally distributed, but my independent is not...therefore, should I use PROC REG or PROC CORR in SAS?</p> | g13616 | [
0.03812205046415329,
-0.0409565307199955,
-0.013836108148097992,
-0.014857685193419456,
0.026228711009025574,
0.029864134266972542,
0.010296528227627277,
0.006222797092050314,
-0.027929946780204773,
-0.05673205479979515,
0.04808906093239784,
0.011204158887267113,
-0.00974347535520792,
-0.0... |
<p>I have a 70 / 30 ratio for train / test data. I have a relatively small feature set (6 features), however, I still want to do feature selection to get rid of any redundant features (I'm guessing 1 of my features quite possibly is). Would running the feature selection on data later used for training / test bias the r... | g58508 | [
-0.0026933702174574137,
-0.01626744121313095,
0.00042456286610104144,
-0.0008378353086300194,
-0.022299421951174736,
-0.021063612774014473,
0.06002896651625633,
0.007076698821038008,
-0.042110931128263474,
-0.04474093019962311,
0.017534734681248665,
0.0454443134367466,
0.03678914159536362,
... |
<p>I have googled and read a lot from Matlab documents but helpless in solving the following problems concerning nonlinear regression.I have a single observation vector consisting of 200 measurements <code>y</code>. The model is unknown. The command <code>nlinfit(x, y, modelFun)</code> needs a model as an input but I w... | g58509 | [
0.02933722920715809,
-0.029550205916166306,
0.005638253875076771,
-0.034932538866996765,
0.000057005509006557986,
-0.05211525782942772,
0.012406447902321815,
0.030460188165307045,
-0.05775083974003792,
-0.033557407557964325,
-0.0734478011727333,
0.010151635855436325,
0.04846292734146118,
0... |
<p>For analyzing data from a biophysics experiment, I'm currently trying to do curve fitting with a highly non-linear model. The model function looks basically like:</p>
<p>$y = ax + bx^{-1/2}$</p>
<p>Here, especially the value of $b$ is of great interest.</p>
<p>A plot for this function:</p>
<p><img src="http://i.... | g58510 | [
0.07499709725379944,
-0.041173055768013,
0.001611563260667026,
0.0003214971220586449,
-0.005123126786202192,
-0.05534183233976364,
0.01554915215820074,
-0.013160343281924725,
-0.00025626507704146206,
0.025046110153198242,
0.03272140771150589,
-0.0045514218509197235,
0.041314732283353806,
0... |
<p>I'm working in bioanalytical chemistry and am trying to find a suitable lack-of-fit test for the calibration curve (predictor variable=concentration, response variable=analytical signal). The calibration curves in bioanalytical chemistry are usually heteroscedastic with the variance increasing with concentration, so... | g13620 | [
0.01896604709327221,
-0.04248998314142227,
0.011845961213111877,
-0.027787599712610245,
0.014001565985381603,
-0.018534313887357712,
0.010670737363398075,
-0.00766353914514184,
-0.017298728227615356,
-0.01785670779645443,
0.015800658613443375,
-0.011172523722052574,
0.024347465485334396,
0... |
<p>Does anyone know that are there some assumptions for Copula method.
I heard from someone that The data should be i.i.d (independent and identically distributed).
Let's say. If I want to capture the dependence structure between two variables.
I have to use marginal distribution to transform data to rank space, then I... | g13621 | [
0.038741834461688995,
-0.02717895247042179,
0.009000697173178196,
-0.06743971258401871,
-0.024887166917324066,
0.020245036110281944,
0.04456828907132149,
-0.006858764681965113,
-0.08846398442983627,
0.007832584902644157,
0.0038246524054557085,
0.012398031540215015,
0.030864568427205086,
-0... |
<p>As we know probabilistic Hermite polynomials are orthogonal with respect to the weight function $\frac{1}{\sqrt{2 \pi}} e^{-x^2/2}$ (density of standard normal).</p>
<p>I have a distribution which is a mixture of two Gaussians each having $(Mean, variance) =(1 ,\sigma^2)$ and $(-1,\sigma^2)$ respectively.</p>
<p... | g58511 | [
-0.022499874234199524,
-0.07408798485994339,
-0.007600832264870405,
-0.03394586220383644,
-0.02281836047768593,
0.023417728021740913,
-0.012122544459998608,
0.03477543219923973,
-0.029084209352731705,
0.03252389281988144,
-0.007369312923401594,
0.038721323013305664,
0.061048708856105804,
-... |
<p>I have a model that attempts to predict a nation's quality of life index by it's moral indifference to contraception and moral rejection of gambling. Initially the model contained several predictors, but I eliminated most using backwards elimination via AIC. Here is a summary of the model (generated using R):</p>
<... | g58512 | [
0.018221857026219368,
-0.0029843645170331,
-0.0037284891586750746,
-0.054831039160490036,
-0.04755401983857155,
0.046305835247039795,
0.02238711342215538,
-0.016985757276415825,
-0.040766458958387375,
0.0752258151769638,
-0.009773780591785908,
0.02420291118323803,
0.026055386289954185,
-0.... |
<p>What does having "constant variance" in the error term means. As I see it , we have a data with variable and 1 independent variable. This is one assumption of linear regression. I am wondering what this homoscedasticity means. Since if I am having 500 rows I would have single variance value which is obviously const... | g13622 | [
0.03862052783370018,
-0.024766264483332634,
-0.023935286328196526,
-0.00391941424459219,
-0.0032826075330376625,
0.01597679778933525,
0.033884428441524506,
0.00791640393435955,
-0.05885013937950134,
-0.06147994473576546,
-0.035110682249069214,
0.06615616381168365,
-0.03478527441620827,
0.0... |
<p>I have a linear AR(2) regression model of an time series that looks like this:</p>
<p>$y_{t} = \beta_0 + \beta_1 y_{t-1} + \beta_2 y_{t-2} + \beta_3 x_t + \epsilon_t$</p>
<p>I am modelling the contribution of the time series $\{ y_{t-1}, y_{t-2}, x_t\}$ on tomorrow's $y$, $y_{t}$. </p>
<p>I want to test whether t... | g58513 | [
0.01833365112543106,
-0.037515487521886826,
-0.014340340159833431,
-0.04965076223015785,
0.0450553335249424,
-0.05056888237595558,
0.03819800540804863,
0.019748931750655174,
-0.053651414811611176,
0.017100654542446136,
-0.019244389608502388,
0.04305505380034447,
0.01415223442018032,
0.0100... |
<p>In his book <em>Statistical Learning Theory</em> (1998), Vladimir Vapnik proves an inequality needed to prove a bound on the risk for indicator loss functions. Theorem 4.1
on page 133 he derives the following inequalities</p>
<p>$$I \ge \int_{Z_2} [\nu(\alpha^*,Z_2)-P(\alpha^*)-1/l]dF(Z_2)=P \left[\nu(\alpha^*,Z_2... | g58514 | [
-0.07566013932228088,
-0.02606607787311077,
-0.007686921861022711,
0.025649337098002434,
0.0007103802054189146,
0.006753180176019669,
0.0648568719625473,
-0.024218764156103134,
-0.0033994517289102077,
-0.027560872957110405,
-0.053615037351846695,
0.052665743976831436,
0.03232696279883385,
... |
<p>Mathematics has its famous <a href="http://en.wikipedia.org/wiki/Millennium_Prize_Problems">Millennium Problems</a> (and, historically, <a href="http://en.wikipedia.org/wiki/Hilbert%27s_problems">Hilbert's 23</a>), questions that helped to shape the direction of the field.</p>
<p>I have little idea, though, what th... | g58515 | [
0.004948532674461603,
0.06519713252782822,
0.008536646142601967,
-0.02908438816666603,
-0.07929366081953049,
0.011964675970375538,
0.0478544682264328,
0.012881213799118996,
-0.0028717820532619953,
-0.04525315761566162,
0.02712235599756241,
-0.014158274978399277,
0.07716861367225647,
0.0166... |
<p>No regular here will be unaware of the perils of using stepwise and similar automatic methods for variable selection in regression analysis. But preferred alternatives, such as the lasso or elasticnet, have there own difficulties.</p>
<p>I can't find anywhere in the archive here a discussion of the methods provided... | g58516 | [
0.023974424228072166,
-0.04543909430503845,
0.015186188742518425,
0.011418935842812061,
-0.008220751769840717,
-0.05576014891266823,
0.03512908145785332,
0.027225693687796593,
-0.004128727130591869,
0.003999901469796896,
-0.003788197413086891,
0.025883758440613747,
0.037321727722883224,
0.... |
<p>I used to analyse items from a psychometric point of view. But now I am trying to analyse other types of questions on motivation and other topics. These questions are all on Likert scales. My initial thought was to use factor analysis, because the questions are hypothesised to reflect some underlying dimensions.</p>... | g58517 | [
-0.020192522555589676,
0.02732754684984684,
0.005752609111368656,
-0.06976509839296341,
0.02072933502495289,
0.012262040749192238,
0.027342770248651505,
0.002226015320047736,
-0.05363934114575386,
0.016343841329216957,
0.031570661813020706,
-0.016902485862374306,
0.02568952366709709,
0.025... |
<p>I have a serie with 850 observations, and I need to fit the Pareto IV distribution. How could I do this in R?</p>
<p>I read the guide VGAM, however, I'm not able to run it.</p>
<p>If anyone knows, please provide me with a detailed (step by step) answer so that I can understand it...</p> | g58518 | [
0.03738193213939667,
0.006359892897307873,
-0.015328828245401382,
-0.0363176167011261,
-0.03874440863728523,
-0.04638431966304779,
0.024064311757683754,
0.037462424486875534,
-0.046939652413129807,
0.002020122716203332,
-0.06481962651014328,
-0.013223530724644661,
0.010240888223052025,
-0.... |
<p>I am curious if there is a transform which alters the skew of a random variable without affecting the kurtosis. This would be analogous to how an affine transform of a RV affects the mean and variance, but not the skew and kurtosis (partly because the skew and kurtosis are defined to be invariant to changes in scale... | g13625 | [
-0.05761272832751274,
0.009692913852632046,
0.010718370787799358,
-0.07526753842830658,
-0.028385885059833527,
-0.015394858084619045,
-0.06387574225664139,
0.028313515707850456,
0.0024514601100236177,
0.028149321675300598,
0.016342388466000557,
0.03776295855641365,
-0.003655295353382826,
0... |
<p>I am trying fit a Cox Proportional Hazard model with coxph with a cmoputer of 12GB of RAM. It keeps running out of memory. Is there a biglm equivalent of coxph?</p> | g58519 | [
0.06537418067455292,
-0.027858110144734383,
-0.0019824074115604162,
-0.05438883230090141,
-0.006521051749587059,
-0.0031918471213430166,
-0.017806608229875565,
0.009981868788599968,
-0.04760965332388878,
-0.022156769409775734,
0.019021807238459587,
0.009589944034814835,
0.0462651252746582,
... |
<p>I have survey data with design weights for stratified sampling. My ultimate goal is to estimate Cramér's $V$ for contingency tables, a Pearson $\chi^2$ based measure. To account for the weights, I am thinking about using Rao-Scott adjustment to estimate $\chi^2$ statistics. However, then it is not clear how to get t... | g13626 | [
0.019269943237304688,
-0.039500847458839417,
-0.021652191877365112,
-0.07047863304615021,
0.020191678777337074,
-0.021676350384950638,
-0.006283551920205355,
0.011406187899410725,
-0.022335564717650414,
0.030128849670290947,
0.049176931381225586,
0.024817271158099174,
-0.017168324440717697,
... |
<p>This is a general question regarding GLM with binomial distribution. I use the following data (with $N=400$ observations) as an example (predict toxicity using treatment):</p>
<pre><code>mod1 <- glm(toxicity~treatment, family=binomial, data=Dat)
</code></pre>
<p>The description of the model can be written as:</... | g58520 | [
-0.017387066036462784,
-0.05984003469347954,
0.008321625180542469,
0.007594907656311989,
0.057747017592191696,
-0.04919642582535744,
0.015384814701974392,
0.03186315298080444,
-0.06449174135923386,
-0.006677670869976282,
-0.032619986683130264,
0.037367552518844604,
0.06347042322158813,
-0.... |
<p>As I understand it, I need to know at least three aspects (out of four) of my proposed study in order to conduct power analysis, namely:</p>
<ul>
<li>type of test - I intend to use Pearson's r and ANCOVA/Regression - GLM</li>
<li>significance level (alpha) - I intend to use 0.05</li>
<li>expected effect size - I in... | g13628 | [
0.019090060144662857,
-0.015044918283820152,
-0.009176037274301052,
-0.03820670768618584,
-0.0709245428442955,
-0.033869802951812744,
0.0014729441609233618,
0.060560520738363266,
-0.04611938074231148,
-0.002195405075326562,
0.06273186951875687,
0.0299056563526392,
0.02888869307935238,
0.04... |
<p>There is a debate in selecting the smoothign constant in Single Exponentioan Smoothing method by practitioner or considering it as a process parameter?</p>
<p>Could you please provide your opinion regarding this issue?</p> | g42513 | [
0.02476290985941887,
-0.048141080886125565,
0.01763794757425785,
-0.02135559730231762,
0.014651739038527012,
-0.016420459374785423,
0.0715654194355011,
0.054414309561252594,
0.0009936876595020294,
0.02243557758629322,
0.033563125878572464,
0.0442311055958271,
0.006378485821187496,
0.015345... |
<p>I am trying to use PLINK to do a GWAS for a outcome with repeated measures, namely each subject has time1 and time2 observations. Does anybody have some experiences or suggestions for this. I am thinking use a gxe model such as:</p>
<pre><code>plink --bfile mydata --pheno outcomes.txt --gxe --covar time.txt --out r... | g58521 | [
-0.04920925572514534,
-0.017244886606931686,
0.0026810644194483757,
-0.07845862954854965,
-0.012318835593760014,
-0.03436997905373573,
-0.02291359193623066,
0.0020852547604590654,
-0.08541399240493774,
-0.030771920457482338,
0.00911033060401678,
0.004841919522732496,
0.022684846073389053,
... |
<p>I want to know why we can include dummy interaction terms into time series models if they're always non-stationary?</p>
<p>For example let $X_t$ be $I(0)$, $X_t \sim N(\mu,\sigma^2)$ and $D_t \in \{0,1\}$. Suppose the estimation window is $200$ and $D_t =0$ for $t=1,...,100$ and $D_t =1$ for $t=101,...,200$. The i... | g58522 | [
0.015884075313806534,
-0.0036697571631520987,
0.0027766935527324677,
-0.015215180814266205,
0.00986314844340086,
-0.02262493409216404,
0.07185615599155426,
-0.0024961421731859446,
-0.020185375586152077,
0.009465222246944904,
-0.03999713063240051,
0.07323344051837921,
-0.05730583518743515,
... |
<p>I’m reading Wacek’s paper <a href="http://www.casact.org/pubs/forum/05fforum/05f165.pdf" rel="nofollow"><em>Parameter Uncertainty in Loss Ratio Distributions and its Implications</em></a> and trying to figure out how to replicate some of the results. </p>
<p>Table 6, on page 190 of the paper, contains some results.... | g13630 | [
0.04058606177568436,
-0.018629826605319977,
-0.02623268961906433,
-0.00227459822781384,
0.020295338705182076,
-0.0011351961875334382,
0.027429813519120216,
-0.04664153605699539,
-0.0315723642706871,
-0.006339983083307743,
-0.04586377739906311,
0.022504379972815514,
0.04420348256826401,
0.0... |
<p>I am running a least squares regression, and I am trying to estimate the uncertainty on the fit solution. The problem is, I have an uncertainty in my design matrix coefficients as well as in my predictors. So given $||Ax - b||_2$ being minimized, and uncertainties $\sigma_b$ and $\sigma_A$ on the coefficients of $b$... | g42585 | [
-0.0018980782479047775,
-0.041529085487127304,
-0.0009811506606638432,
0.016827015206217766,
0.02569473907351494,
-0.04930964857339859,
0.017950916662812233,
0.0012076362036168575,
-0.030739009380340576,
-0.040387123823165894,
-0.06051278114318848,
0.06251674145460129,
-0.009756181389093399,... |
<p>I have a data set consisting of about a quarter-million objects, each of which may have any of 30 particular features. So I might have</p>
<p>Object 1: feature 3, feature 7<br>
Object 2: feature 3, feature 29, feature 30<br>
Object 3: feature 3, feature 7<br>
Object 4: feature 1, feature 18, feature 20, feature 28<... | g58523 | [
-0.026157230138778687,
0.04005350545048714,
0.005608470644801855,
-0.061553433537483215,
0.015669766813516617,
-0.03244218975305557,
0.052525486797094345,
-0.026179881766438484,
-0.04290290176868439,
-0.05565493181347847,
0.0009909920627251267,
-0.01582322083413601,
0.05675165727734566,
0.... |
<p>Could anyone please let me know how to implement Naive Bayesian Algorithm in R or SAS?I have got a training dataset with all the categorical predictors and target variable(3 levels).I got to build a model and apply it on a different test dataset along with the probable target and its predicted probability.</p>
<p>T... | g58524 | [
-0.007395382970571518,
-0.06125304475426674,
0.025405291467905045,
-0.0031526864040642977,
-0.039828136563301086,
-0.02204267680644989,
-0.007147188298404217,
0.059266991913318634,
-0.029750823974609375,
-0.01716129295527935,
0.0011074256617575884,
0.024631459265947342,
0.04332958161830902,
... |
<p>"An insurance company receives claims at a rate of two per week, the size of a claim in pounds having mean 100 and standard deviation 50. Assuming the compound Poisson process as a model, and using normal approximations, find the probabilities that, in a period of 50 weeks the average size of claim will exceed £110"... | g58525 | [
0.04052840918302536,
0.027595635503530502,
-0.0189896821975708,
-0.0405147559940815,
0.026025477796792984,
-0.020638758316636086,
0.038098447024822235,
-0.02058594860136509,
0.009579279460012913,
-0.0388200543820858,
0.03226408734917641,
0.041949521750211716,
0.020839203149080276,
-0.01289... |
<p>A short <code>mice</code>-related question as follows: when running simple <a href="http://cran.r-project.org/web/packages/mice/index.html" rel="nofollow">mice</a> imputation the function goes through well. But <code>complete()</code> function does not substitute my <code>NA</code>'s at all. I guess it must be somet... | g37769 | [
0.06729584187269211,
0.006001432426273823,
-0.005321732722222805,
-0.06888394057750702,
0.036995649337768555,
-0.05708855018019676,
0.053899481892585754,
0.03465338423848152,
-0.02906167134642601,
-0.006514124572277069,
-0.015022887848317623,
0.036621417850255966,
0.05565199628472328,
0.03... |
<p>I'm looking to construct a 3-D surface of a part of the brain based on 2-D contours from cross-sectional slices from multiple angles. Once I get this shape, I want to "fit" it to another set of contours via rescaling.</p>
<p>I'm aspiring to do this in the context of an MCMC analysis (So as to be able to make infere... | g42589 | [
0.04114764556288719,
0.002708358922973275,
0.002869939198717475,
-0.018822122365236282,
-0.1119236871600151,
-0.030201124027371407,
0.005944056436419487,
0.05514659360051155,
-0.04654292017221451,
0.021058019250631332,
0.043818291276693344,
-0.04086926579475403,
0.07056642323732376,
-0.031... |
<p>A question which bothered me for some time, which I don't know how to address:</p>
<p>Every day, my weatherman gives a percentage chance of rain (let's assume its calculated to 9000 digits and he has never repeated a number). Every subsequent day, it either rains or does not rain.</p>
<p>I have years of data - pct... | g13634 | [
0.015484144911170006,
-0.018744388595223427,
-0.015180938877165318,
-0.023296624422073364,
-0.006686727050691843,
0.03617827221751213,
0.02518814615905285,
-0.012010835111141205,
-0.003668848192319274,
-0.06736008077859879,
0.041069384664297104,
0.04277294874191284,
-0.017674464732408524,
... |
<p>I posted this on mathoverflow, but they sent me here. This question relates to a problem I had at work a while ago, doing a little data mining at a car rental company. Names changed, of course. I'm using Oracle DBMS if it matters.</p>
<p>There was a flight of steps out the front of our building. It had a dodgy step... | g13635 | [
-0.006901377812027931,
0.05143286660313606,
0.026836061850190163,
0.05540333315730095,
0.0060709440149366856,
0.026765652000904083,
0.09616977721452713,
0.031616225838661194,
0.04073302820324898,
-0.03335944563150406,
-0.025219030678272247,
-0.028002548962831497,
0.05242592841386795,
0.030... |
<p>The question is in the header, but I would extend the context a bit.</p>
<p>Next semester I am due to be a TA in a course in statistics, where I would need to help sociology students learn to use SPSS. I don't know SPSS, yet, and would like to learn how to use it.</p>
<p>I was thinking of taking a simple dataset,... | g58526 | [
0.0013972162269055843,
0.02088768035173416,
0.00720099825412035,
-0.05177269130945206,
-0.09277214109897614,
-0.023755306378006935,
-0.01078763883560896,
0.019654422998428345,
0.008409189991652966,
-0.07646015286445618,
0.04152199253439903,
-0.03169415891170502,
0.1436058133840561,
0.08883... |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.