question stringlengths 37 38.8k | group_id stringlengths 2 6 | sentence_embeddings listlengths 768 768 |
|---|---|---|
<p>I am performing the test to see if there is any differences between the preferences of chocolate for male and female students. My null hypothesis is that there is no difference. </p>
<p>My data is not normally distributed and data transformations failed to 'squash' the data. Therefore I performed the F test on the ... | g66201 | [
0.012166260741651058,
-0.019076131284236908,
-0.01300893072038889,
-0.021786468103528023,
0.02678270824253559,
0.009475737810134888,
0.0646374374628067,
-0.008081239648163319,
-0.006436548195779324,
-0.058111973106861115,
-0.06573956459760666,
0.016849398612976074,
0.024453146383166313,
-0... |
<p>I am using modprobe syntax on SPSS to test an interaction between narcissism and rumination on a dependent variable, aggression.</p>
<p>I get a significant effect of rumination (<em>b</em> = .6450, <em>t</em> = 2.32, <em>p</em> = .0216) and significant effect of narcissism (<em>b</em> = .5646, <em>t</em> = 2.5, <em... | g66202 | [
-0.025029733777046204,
0.02043602429330349,
-0.013894141651690006,
-0.055958349257707596,
0.022097179666161537,
-0.04006893187761307,
0.04315005615353584,
0.02158859558403492,
-0.038823626935482025,
-0.051381517201662064,
-0.009879511781036854,
0.021982749924063683,
0.06966874748468399,
-0... |
<p>What are the assumptions behind each of the following types of tests (i.e. what are the prerequisites to running each test).</p>
<ol>
<li>Paired-t</li>
<li>Sign</li>
<li>Two-Sample t</li>
<li>Pooled Two-Sample t</li>
<li>Two Proportions</li>
<li>F</li>
</ol>
<p>I really am getting confused seeing what would warran... | g66203 | [
0.0037620486691594124,
-0.03221459686756134,
-0.016944220289587975,
-0.06885740160942078,
0.054314617067575455,
-0.004419042728841305,
0.03697490692138672,
0.005379304755479097,
0.0052346340380609035,
-0.022466572001576424,
0.016673212870955467,
0.020639656111598015,
0.05499055236577988,
0... |
<p>Say there is a random variable <code>X</code> which can take 3 values <code>1</code>,<code>2</code>,<code>3</code> with equal probability. The task is to draw realizations from this random variable.</p>
<p>Any simple textbook will say consider a realization as <code>1</code> if you get a realization from Uniform di... | g45361 | [
0.005199451930820942,
0.021458329632878304,
-0.034192271530628204,
-0.10102140158414841,
-0.0013878083555027843,
0.05445578321814537,
-0.019350744783878326,
0.0297121312469244,
-0.02954668365418911,
-0.02466553822159767,
-0.050444141030311584,
-0.03269932046532631,
0.018857505172491074,
0.... |
<p>I need to analyze the 100k MovieLens dataset for clustering with two algorithms of my choice, between the likes of k-means, agnes, diana, dbscan, and several others. What tools (like Rattle, or Weka) would be best suited to help me make some simple clustering analysis over this dataset?</p> | g66204 | [
-0.023107357323169708,
0.01879972591996193,
-0.015688059851527214,
-0.015687638893723488,
-0.011342539452016354,
-0.08801354467868805,
0.00946781225502491,
0.033109769225120544,
-0.00825846754014492,
0.00981740839779377,
-0.01500016637146473,
0.017177265137434006,
0.12829020619392395,
0.02... |
<p>I have a set of numbers which are assumed to be coming from a Poisson distribution. The set has some outliers also and because of that, maximum likelihood estimates are badly affected. I heard that robust estimation procedures can help in such a situation. Can any one explain how to do this? I am not a statistics st... | g66205 | [
0.05364881828427315,
-0.054298944771289825,
0.007191536948084831,
-0.01884462684392929,
-0.017456162720918655,
-0.009981726296246052,
-0.002395560732111335,
0.023957617580890656,
-0.05829133465886116,
-0.00668633496388793,
-0.033578820526599884,
-0.006852578837424517,
0.009480295702815056,
... |
<p>Is there a standard and accepted method for selecting the number of layers, and the number of nodes in each layer, in a FF NN? I'm interested in automated ways of building neural networks.</p> | g45365 | [
-0.010885038413107395,
0.045611754059791565,
0.028795957565307617,
-0.0052837166003882885,
0.02144811861217022,
-0.10628782957792282,
0.03130853548645973,
0.022732583805918694,
-0.034304678440093994,
-0.05339399352669716,
-0.0486026369035244,
-0.06329624354839325,
0.08577354997396469,
0.06... |
<p>I'm pretty sure that I'm missing something obvious here, but I'm rather confused with different terms in the time series field. If I understand it correctly, serially autocorrelated errors are a problem in regression models (see for example <a href="http://stats.stackexchange.com/questions/19321/can-i-trust-a-regres... | g66206 | [
0.04876411333680153,
-0.057852014899253845,
0.0013750665821135044,
-0.04617523029446602,
0.02367510460317135,
-0.017090165987610817,
0.06836135685443878,
0.038533467799425125,
-0.014214872382581234,
-0.025705650448799133,
-0.007891274057328701,
0.04630615562200546,
0.03032693639397621,
-0.... |
<p>After learning about a few machine-learning models (NN, SVM, decision trees), I was wondering if these models are able to find inherent relationships when learning. For example, if I feed it two inputs A and B, but it is really A - B or the percent change from A to B that determines the output (but this relationship... | g66207 | [
-0.016377445310354233,
-0.03973675146698952,
0.02787506952881813,
0.00417602714151144,
0.011158175766468048,
-0.0329287089407444,
-0.04519859701395035,
-0.02038002759218216,
-0.016258835792541504,
0.006484592333436012,
-0.0218521635979414,
0.009773126803338528,
0.07804613560438156,
0.01347... |
<p>I am looking at pre and post test depression scores in a 2x3 design with treatment and genotype as the IVs and depression score as the DV. However, I have to use one depression test for younger people and a different depression test for older people, because I would like to covary out age. I think I need a repeate... | g66208 | [
-0.02667883224785328,
-0.05112141743302345,
-0.01816212385892868,
-0.05036748945713043,
-0.054406438022851944,
0.01772313006222248,
0.028686145320534706,
-0.03934480622410774,
0.019961027428507805,
-0.017952540889382362,
-0.0011313266586512327,
0.013722379691898823,
-0.009861267171800137,
... |
<p>Suppose a data set has the following binary values for the variable <strong>z</strong>:</p>
<pre><code>z x y
1
0
1
1
0
1
</code></pre>
<p>The variables are <strong>x</strong> and <strong>y</strong>. The training data set consists of the first three values. The test data set contains the last three values.</p>
... | g66209 | [
0.04371005296707153,
0.011480600573122501,
0.0022244220599532127,
0.0026537433732300997,
0.02725331112742424,
0.0039338115602731705,
0.02740374393761158,
0.030269693583250046,
-0.06295575201511383,
-0.002471119863912463,
-0.020824650302529335,
0.03754013776779175,
0.00005219122249400243,
0... |
<p>The problem is defined as
$$
\min_{x} \Bigg\{ a{\|x\|}^2+\frac{b}{2}{\|x-c\|}^2 \Bigg\}
$$
where $x\in R^{n \times 1}, c \in R^{n \times 1}$ and $a,b$ are scalars.
Equations 2.5 to 2.8 of <a href="http://www.caam.rice.edu/~optimization/L1/GroupSparsity/group110419.pdf" rel="nofollow">this paper</a> say this could b... | g25140 | [
-0.030730361118912697,
0.007872963324189186,
-0.013778552412986755,
0.036461785435676575,
0.005221119150519371,
-0.018160615116357803,
0.04590429738163948,
0.04930732026696205,
-0.0608089379966259,
0.0025194725021719933,
-0.04268136993050575,
0.06702764332294464,
0.02748194895684719,
0.050... |
<p>I have obtained from a paper next results:</p>
<p>Variable 1: Mean=165, sd=15</p>
<p>Variable 2: Mean=149, sd=18</p>
<p>Variable 3: Mean=134, sd=25</p>
<p>I have simulated normal distributions using rnorm.
This is the way (with a n=1000): rnorm(1000,165,15). The same procedure with the others.</p>
<p>So now I w... | g66210 | [
0.03734444081783295,
-0.04830952361226082,
-0.018755849450826645,
-0.030574122443795204,
-0.03729274123907089,
-0.0009936325950548053,
0.012831154279410839,
-0.06462647765874863,
-0.05173557996749878,
0.003608479630202055,
0.020563924685120583,
0.00024328487052116543,
0.023882117122411728,
... |
<p>When using Using Yule Walker equations for getting ACF and PACF, is it essential that the time series has to be stationary? In other words, do we really need Box-Cox transformations before we use Yule Walker for ACF and PACF</p>
<p>Thanks,
Ratheen</p> | g25141 | [
0.008188285864889622,
0.04340774565935135,
0.008749820291996002,
-0.06053633242845535,
0.023944241926074028,
-0.055841680616140366,
0.05440787598490715,
0.005098947789520025,
-0.04104940593242645,
-0.035100337117910385,
-0.02950282394886017,
-0.001509387046098709,
0.0761537104845047,
0.011... |
<p>I recently found it necessary to derive a pdf for the square of a normal random variable with mean 0. For whatever reason, I chose not to normalise the variance beforehand. If I did this correctly then this pdf is as follows:</p>
<p>$$
N^2(x; \sigma^2) = \frac{1}{\sigma \sqrt{2 \pi} \sqrt{x}} e^{\frac{-x}{2\sigma^2... | g66211 | [
0.03300318866968155,
-0.04653211310505867,
-0.0095905102789402,
-0.07511121034622192,
0.018702439963817596,
-0.011827549897134304,
0.021570386365056038,
-0.006267908029258251,
0.0020004648249596357,
0.02536512166261673,
0.002669338136911392,
-0.002656778320670128,
0.0005272427806630731,
-0... |
<p>Looking for the best formula to compare two sets of numbers</p>
<p><strong>Set #1 - Rank: Smaller numbers indicate higher "rank" (Ex: 1 is the best, 1,000,000 is the worst)</strong></p>
<p><strong>Set #2 - Number of Items: The more items in a category, the worse off the category is</strong></p>
<p>This formula is... | g45369 | [
0.005592991132289171,
0.02323038876056671,
-0.025084596127271652,
-0.02354712225496769,
-0.0004723522870335728,
-0.05550084263086319,
-0.003715262282639742,
-0.04473975673317909,
-0.039038900285959244,
-0.016801683232188225,
0.03680187836289406,
0.022380128502845764,
0.07714436948299408,
0... |
<p>I want to compare two clustering algorithms. I took data that the first algorithm gathered in one cluster. The second algorithm gave 3 clusters for the same points. In order to compare the results, I tried to compute the two different silhouette for these algorithms, but I realized that in the first case, since ther... | g66212 | [
0.06688125431537628,
-0.042511630803346634,
0.014896240085363388,
0.00047028050175867975,
0.034041617065668106,
-0.039028435945510864,
0.005534014198929071,
0.02123418264091015,
-0.044624850153923035,
0.012036093510687351,
-0.049022164195775986,
0.010719369165599346,
0.09223019331693649,
0... |
<p>I am taking a graduate course in Applied Statistics that uses the following textbook (to give you a feel for the level of the material being covered): <a href="http://amzn.com/0471072044" rel="nofollow">Statistical Concepts and Methods</a>, by G. K. Bhattacharyya and R. A. Johnson.</p>
<p>The Professor requires us ... | g45373 | [
0.00821991078555584,
-0.020218929275870323,
0.004090007860213518,
-0.07709305733442307,
-0.035516295582056046,
-0.00467896182090044,
-0.014038655906915665,
-0.021548544988036156,
-0.03146328404545784,
-0.029170287773013115,
0.08948452770709991,
-0.03774654120206833,
0.08787039667367935,
0.... |
<p>I have a time series $x_t$ which may go through different phases of volatility. One example might be some stock that has high variance from 9 AM to 11 AM, low variance from 11 AM to 2 PM, and then high variance again afterwards. Is there a way to identify these different periods of variance?</p>
<p>I am thinking ... | g45374 | [
0.021593106910586357,
-0.002876251470297575,
-0.011709350161254406,
0.029209529981017113,
-0.0168368611484766,
-0.08267604559659958,
0.021743400022387505,
0.004935168661177158,
-0.021998556330800056,
0.000346159387845546,
-0.005777840502560139,
0.05405253916978836,
0.046683043241500854,
0.... |
<p>My question: how can I analyze the effects of multiple within-subjects factors when my design does NOT include the all combinations of their factor levels, as would be required by a standard factorial ANOVA?</p>
<p>Here's my design:</p>
<p>Each participant is trained to discriminate 2 categories in each of 2 domai... | g45375 | [
-0.034398969262838364,
0.010036755353212357,
-0.012248466722667217,
0.008832125924527645,
0.0023719072341918945,
-0.014345113188028336,
0.03322563320398331,
0.02210700698196888,
-0.020422203466296196,
-0.042593151330947876,
-0.00962140690535307,
0.0280532855540514,
0.03788846358656883,
0.0... |
<p>I have the following data, which is the output from the <a href="http://bioinformatics.oxfordjournals.org/content/18/2/337.full.pdf+html" rel="nofollow">MS Hudson</a> software. </p>
<pre><code>segsites: 6
positions: 0.1256 0.3122 0.3218 0.4970 0.5951 0.7943
001010
110101
010100
001010
010100
</code></pre>
<... | g330 | [
-0.006669043563306332,
-0.01692046970129013,
-0.013621496967971325,
-0.07419746369123459,
-0.015512112528085709,
-0.044106509536504745,
0.029793210327625275,
0.07373107224702835,
-0.0332503616809845,
0.031307805329561234,
-0.004310433752834797,
-0.010492595843970776,
0.045828960835933685,
... |
<p>I've been looking at some of the packages from the High perf task <a href="http://cran.r-project.org/web/views/HighPerformanceComputing.html" rel="nofollow">view</a> dealing with GPU computations, and given that most GPU seem to be an order of magnitude stronger at performing single precision arithmetics than DP <a ... | g66213 | [
0.016209814697504044,
0.0436476431787014,
-0.022638928145170212,
0.005043317563831806,
0.013274166733026505,
-0.042209725826978683,
0.08157122880220413,
0.011573085561394691,
-0.08198799937963486,
-0.06115055829286575,
-0.00855281576514244,
0.019011948257684708,
0.05964918062090874,
0.0314... |
<p>This is a very basic questions however I have not been able to find an answer.
When you plot your regular bar plot with your standard errors of the means for comparison do you plot the standard errors and means from the raw data ?<br>
Or do you plot the ones predicted by the model you are fitting. Thank you in advan... | g66214 | [
0.0013236856320872903,
-0.07111921161413193,
0.006010506302118301,
-0.050461821258068085,
-0.03639737144112587,
-0.019511189311742783,
0.06826668232679367,
-0.011652497574687004,
-0.04558315500617027,
-0.02144184522330761,
0.021558009088039398,
0.003751011798158288,
0.046358026564121246,
-... |
<p>I have scoured lots of help sites and am still confused about how to specify more complicated nested terms in a mixed model as well. I am also confused as the use of <code>:</code> and <code>/</code> and <code>|</code> in specifying interactions and nesting with random factors using <code>lmer()</code> in the <code>... | g66215 | [
-0.0064231883734464645,
-0.058137405663728714,
-0.0007729280623607337,
-0.01706003211438656,
0.041148629039525986,
-0.0172051303088665,
0.06433123350143433,
-0.0205424502491951,
-0.00555247301235795,
-0.046203259378671646,
-0.007859937846660614,
-0.016506416723132133,
0.04193253070116043,
... |
<p>I have this problem of the following format. </p>
<p>\begin{align*}
x_L &= X\left(\frac{dx_L}{dX}\right) + Y\left(\frac{dx_L}{dY}\right) + Z\left(\frac{dx_L}{dZ}\right)\\
&\\
x_R &= X\left(\frac{dx_R}{dX}\right) + Y\left(\frac{dx_R}{dY}\right) + Z\left(\frac{dx_R}{dZ}\right)\\
&\\
y_L &= X\left(... | g66216 | [
0.04313741996884346,
-0.011660194024443626,
-0.03662813827395439,
0.036702487617731094,
0.018748151138424873,
-0.03353963792324066,
0.045067716389894485,
-0.03810887411236763,
0.010382861830294132,
-0.019844619557261467,
-0.021684912964701653,
0.00862633716315031,
0.010603860020637512,
-0.... |
<p>I made a mixed regression model and I would like to calculate the probability of $Y=1$ for a given value of the predictor for each estimation of the random effect.</p>
<p>I am not sure, given it is a logit link function (binary dependent variable), if I can use that: </p>
<p>$$\frac{\exp(B_0 + B_1X + u)}{(1+\exp(... | g66217 | [
-0.014377770014107227,
-0.030834905803203583,
-0.009135253727436066,
-0.024755265563726425,
0.015160168521106243,
0.000652341463137418,
0.0356619618833065,
0.03364037722349167,
-0.02480139024555683,
-0.09131437540054321,
-0.024094978347420692,
0.05952975153923035,
0.029192419722676277,
0.0... |
<p>Assume:</p>
<ul>
<li>A previous study looking at the relationship between $X$ and $Y$ obtained a correlation of $r = 0.50$ using a sample of $n = 100$. The raw data is not available.</li>
<li>The current study also looking at the relationship between $X$ and $Y$ obtained a correlation of $r = 0.45$ with $n = 50$.</... | g45389 | [
0.04002253711223602,
-0.06674153357744217,
-0.001808591652661562,
-0.02885039895772934,
0.012019176036119461,
0.006376091856509447,
-0.03051077201962471,
-0.0018984349444508553,
-0.011897601187229156,
-0.0030187072698026896,
0.05671889707446098,
0.014075019396841526,
-0.007215194404125214,
... |
<p>I have a question in which it asks to verify whether if the Uniform distribution (${\rm Uniform}(a,b)$) is normalized. </p>
<ol>
<li>For one, what does it mean for any distribution to be normalized? </li>
<li>And two, how do we go about verifying whether a distribution is normalized or not? </li>
</ol>
<p>I under... | g36600 | [
0.0803178921341896,
-0.026644820347428322,
-0.01333248894661665,
-0.0347633920609951,
0.06033237278461456,
-0.018956754356622696,
-0.014341682195663452,
0.03705304488539696,
-0.011983783915638924,
-0.05264060199260712,
-0.023614905774593353,
0.023691605776548386,
0.05125971883535385,
-0.03... |
<p>What diagnostic plots (and perhaps formal tests) do you find most informative for regressions where the outcome is a count variable?</p>
<p>I'm especially interested in Poisson and negative binomial models, as well as zero-inflated and hurdle counterparts of each. Most of the sources I've found simply plot the resi... | g66218 | [
0.047865334898233414,
-0.01962619088590145,
-0.0005879760137759149,
-0.014685023576021194,
-0.06033182516694069,
-0.010646354407072067,
0.0016878016758710146,
-0.012921498157083988,
-0.035149358212947845,
-0.036149803549051285,
0.05193377286195755,
-0.03196699172258377,
-0.010514619760215282... |
<p>Is there any interpretation (graphical or otherwise) of a radial basis kernel SVM being trained with a single feature? I can visualize the effect in 2 dimensions (the result being a separation boundary that is curved rather than a linear line. (e.g <a href="http://en.wikipedia.org/wiki/File:Kernel_Machine.png" rel="... | g66219 | [
0.03115239553153515,
0.013120186515152454,
0.01594896987080574,
-0.010580578818917274,
0.025512419641017914,
-0.059647951275110245,
0.04300772771239281,
0.08256087452173233,
-0.031155705451965332,
-0.04848896339535713,
0.01150504034012556,
0.017543602734804153,
0.06289976835250854,
0.02796... |
<p>Background. </p>
<p>Using non-negative matrix factorisation on mutation data, I classified mutations in samples<br>
based into clusters defined by signatures. </p>
<p>The mutations in each sample are broken down into the three signatures, where each
signature is defined by the probability distribution of seeing... | g66220 | [
0.002278790110722184,
-0.023410281166434288,
0.017320480197668076,
-0.01400024350732565,
0.04748854786157608,
-0.016388554126024246,
0.014994828961789608,
0.04258193075656891,
0.007158789783716202,
0.025204652920365334,
0.017207810655236244,
0.0059783970937132835,
0.04397962614893913,
-0.0... |
<p>Please help interpret results of logistic regression produced by <a href="http://weka.sourceforge.net/doc.dev/weka/classifiers/functions/Logistic.html" rel="nofollow"><code>weka.classifiers.functions.Logistic</code></a> from the WEKA library.</p>
<p>I use numeric data from WEKA examples:</p>
<pre><code>@relation w... | g66221 | [
-0.012793904170393944,
-0.0388956144452095,
0.00828324444591999,
-0.09200800955295563,
0.07379260659217834,
-0.04501650482416153,
0.07382918894290924,
-0.004320133943110704,
-0.05852469429373741,
-0.040155455470085144,
-0.0260865967720747,
0.05490182712674141,
0.041375137865543365,
-0.0004... |
<p>As described in <a href="http://mail.scipy.org/pipermail/scipy-user/2013-February/034141.html" rel="nofollow">this thread</a>, the implementation of <em>Mann-Whitney U</em> <a href="http://docs.scipy.org/doc/scipy/reference/generated/scipy.stats.mannwhitneyu.html" rel="nofollow">provided by scipy</a> doesn't seem to... | g25164 | [
-0.010723356157541275,
-0.028771916404366493,
-0.023307958617806435,
-0.040363047271966934,
0.04808441922068596,
-0.022480813786387444,
0.019676782190799713,
0.026085766032338142,
0.010034466162323952,
-0.06471465528011322,
0.036784350872039795,
0.017652610316872597,
0.0314619354903698,
0.... |
<p>I understand that a normal distribution is a continuous distribution, but I came across this question in my test set that baffles me.</p>
<p><strong>Question:</strong><br>
The toy cars produced in a factory have an average weight of 20 lb. The standard deviation of the individual toy cars is 3 lb. We know the weigh... | g25165 | [
0.05730247497558594,
0.013843962922692299,
-0.01985899731516838,
-0.028743745759129524,
-0.03001834638416767,
0.024303415790200233,
0.019198549911379814,
0.03937622159719467,
-0.040665287524461746,
-0.0523703508079052,
-0.003378084860742092,
-0.06302236020565033,
0.029519302770495415,
-0.0... |
<p>I'm taking a look at randomized results and have a question about an end case. Specifically, suppose my scheme is as follows:</p>
<p>1) I want to ask question Q_A. The probability of answering Q_A in the affirmative is p.</p>
<p>2) I have innocuous question Q_I.</p>
<p>3) I have everyone in my sample flip a coin.... | g25166 | [
-0.018105745315551758,
-0.0002087963803205639,
-0.0034281634725630283,
-0.02423482947051525,
-0.0022847899235785007,
-0.007991007529199123,
0.007862529717385769,
-0.007288857363164425,
-0.02061290852725506,
0.02111377939581871,
0.03648148104548454,
0.020241666585206985,
-0.0225877333432436,
... |
<h2>Context</h2>
<p>Suppose I have two models, $H_1$ and $H_2$ for which I know the prior probabilities $p(H_1)$ and $p(H_2)$.
Furthermore, I know the class-conditional distributions $p(x|H_1)$ and $p(x|H_2)$ of a random variable $X \in \mathbb{R}^n$. I get to observe a realization of $X$, call it $x_0$.</p>
<p>The p... | g25167 | [
0.006706481799483299,
-0.01092487946152687,
-0.02611972764134407,
-0.011225921101868153,
0.0070848409086465836,
-0.025861144065856934,
-0.009979326277971268,
0.03589508682489395,
-0.04995962232351303,
-0.028182433918118477,
-0.000442587275756523,
0.021339675411581993,
0.08411575853824615,
... |
<p>I have data which correspond to a corner solution. The Tobit-model seems to be adequate for this data. However, I also wants to control for a baseline variable (t-1) and unobserved heterogenity. This is normally not permissable in the Tobit model.</p>
<p>I understand that Wooldridge have solved the problem in this ... | g66222 | [
0.021481433883309364,
0.007201641798019409,
-0.006240495480597019,
-0.06184472516179085,
0.032973840832710266,
0.0027933274395763874,
0.010919715277850628,
0.018761107698082924,
-0.05107242241501808,
0.01728910207748413,
0.018682081252336502,
0.05691258981823921,
0.09043147414922714,
-0.02... |
<h2>Context</h2>
<p>I must find the general form of a linear equation. The $X$ and $Y$ values are the location coordinates of touches on a screen. I want to find the best fit line, described by equation $mX + nY + p = 0$ , so I need to find $m, n, p$.</p>
<p>I want to be able to make regression of horizontal lines as... | g66223 | [
0.015585450455546379,
-0.033889416605234146,
-0.03157947584986687,
-0.010449668392539024,
0.005322212353348732,
-0.03086332231760025,
0.050890788435935974,
0.012492016889154911,
-0.03302896022796631,
-0.054272379726171494,
-0.0029847549740225077,
-0.012339860200881958,
0.060526296496391296,
... |
<p>I'm dealing with a system which monitors and records a time series (half hourly) which I plan to use to build a double seasonal time model (if possible using something that already exists, such as tbats from R's forecast).</p>
<p>My issues is related to the fact that I don't plan to build this model very often.
Let... | g66224 | [
0.004333211574703455,
-0.010556203313171864,
0.014277800917625427,
-0.01616625115275383,
-0.049672145396471024,
-0.015543659217655659,
0.06634040176868439,
-0.023798378184437752,
-0.052745550870895386,
-0.03271495923399925,
0.025683438405394554,
-0.01705746538937092,
0.08655323088169098,
0... |
<p>First, sorry for my poor english..</p>
<p>I'm trying to implement Discriminative Restricted Boltzmann Machine (<a href="http://machinelearning.org/archive/icml2008/papers/601.pdf" rel="nofollow">paper</a>), but I'm having some trouble in computing <code>p(y|x)</code> because its value explodes while computing the p... | g25169 | [
0.025311363860964775,
0.022913414984941483,
-0.010432986542582512,
-0.021440915763378143,
0.018021753057837486,
-0.028091583400964737,
-0.01759730465710163,
0.00823506060987711,
-0.011665316298604012,
-0.06680382043123245,
-0.039007268846035004,
0.07947172224521637,
0.052677277475595474,
0... |
<p>I have a bivariate discrete numerical dataset and would like to reduce its dimensions to a single variable. A 9 x 8 table of counts of the (x,y) data values is:</p>
<pre><code> 0 1 2 3 4 5 6 7
-----------------------
8 | 10 38 58 79 50 19 15 1
7 | 22 61 67 86 43 19 7 0
6 | 44 70 44 44 19 6 2 0
5 | ... | g66225 | [
0.052588436752557755,
-0.017722738906741142,
0.016489194706082344,
-0.09268046170473099,
-0.01202362310141325,
-0.03584253415465355,
-0.0057162330485880375,
-0.0249838475137949,
-0.04337584599852562,
-0.025774721056222916,
0.01785973273217678,
0.00515109533444047,
0.03760189563035965,
-0.0... |
<p>Given $c>0$ and define a function $f:(0,\infty)\mapsto \mathbb{R}$ by
\begin{equation}
f(\sigma)=\frac1{\sqrt {2\pi}\sigma}\int_{-\infty}^\infty\max\{-c,\min\{x,c\}\}^2e^{-\frac{x^2}{2\sigma^2}}.
\end{equation}
We can see $f$ as the second moment of $X_c=\max\{-c,\min\{X,c\}\}$ where $X\sim N(0,\sigma^2)$. I coul... | g66226 | [
-0.015439681708812714,
-0.0075842831283807755,
-0.02989248000085354,
-0.024975743144750595,
0.045777518302202225,
-0.03675447776913643,
-0.002148686209693551,
0.0037793959490954876,
-0.07366420328617096,
-0.004024910274893045,
-0.03623148053884506,
0.035169534385204315,
0.024068525061011314,... |
<p>Let's say that I have a categorical variable which can take the values A, B, C and D. How can I generate 10000 random data points and control for the frequency of each? For example:</p>
<p>A = 10%
B = 20%
C = 65%
D = 5%</p>
<p>Any ideas how I can do this?</p> | g49499 | [
-0.005436805542558432,
-0.002509653801098466,
-0.001183250336907804,
-0.07317207753658295,
0.03812592476606369,
-0.07158000022172928,
0.002812497317790985,
0.052783332765102386,
-0.011385883204638958,
-0.009779097512364388,
-0.040448229759931564,
-0.005055746994912624,
0.0603143572807312,
... |
<p>I'm using logistic regression to predict student retention in an online course. </p>
<p>I have a data of student interactions within a web platform of an online course. The course spans 6 weeks, with new lecture resources and new assignments uploaded at the beginning of each week. The weekly assignments due at the... | g66227 | [
-0.013631266541779041,
-0.06437080353498459,
0.005855964962393045,
-0.03634900972247124,
0.008663990534842014,
-0.028323212638497353,
0.016192693263292313,
-0.005388009827584028,
-0.01732878014445305,
-0.044506609439849854,
0.04463963210582733,
-0.040175095200538635,
0.06413991749286652,
0... |
<p>I want to plot using GNUplot a bunch of data that is in this form:</p>
<pre><code>123 130 5
</code></pre>
<p>... where the first number is the x starting value, the second is the x ending value, and the 3rd number is the y value.</p>
<p>Ideally I would plot these in an accumulative/stacked manner.</p>
<p>Is ther... | g66228 | [
-0.0031741897109895945,
0.05421079695224762,
-0.0030595744028687477,
-0.05848938971757889,
-0.009234150871634483,
-0.020212145522236824,
-0.04910656064748764,
-0.004378828685730696,
-0.07097850739955902,
-0.0026306938380002975,
-0.0046136826276779175,
0.019664278253912926,
0.0248371474444866... |
<p>If I have the following <code>sensitivity</code> and <code>specificity</code> values, what is the best decision we can say in this case?</p>
<pre><code>sensitivity specificity
----------- -----------
66.3 74.7
87.2 65.9
56.4 76.4
79.5 94.3
</code></pre... | g66229 | [
0.05404436215758324,
-0.0002530692727304995,
-0.0003752700868062675,
-0.022144420072436333,
0.04791880026459694,
-0.017000991851091385,
-0.008089411072432995,
0.015809880569577217,
-0.02007163129746914,
-0.006249969359487295,
-0.011629571206867695,
0.06929422169923782,
0.05844429135322571,
... |
<p>I am trying to analyze my data using Multinomial Logistic Regression whereby my dependent variable is a clinical outcome (sick vs healthy) and 1 independent variables (Factors) are in several categories.</p>
<p>The problem I have is trying to figure out how I can set one of the category as a reference group in SPSS... | g66230 | [
-0.06002681702375412,
-0.05025121197104454,
-0.0233232993632555,
-0.04811979457736015,
-0.04014814272522926,
-0.06917773187160492,
-0.0409478060901165,
0.015185642056167126,
-0.05917946621775627,
-0.00994661170989275,
0.018848327919840813,
0.05313670635223389,
0.053768184036016464,
0.01187... |
<p>I'm planning a study using Structural Equation Modelling to test different accounts of language learning. I would like to study a group of children with language difficulties. However, they are very hard to recruit and I'm aware that these models typically require at least 200 participants. One possibility would be<... | g66231 | [
-0.04138420894742012,
-0.003437655745074153,
-0.0006735351053066552,
-0.06386039406061172,
-0.0048524001613259315,
0.008598579093813896,
-0.0023352026473730803,
0.0722232535481453,
-0.003705606795847416,
0.013035726733505726,
-0.022356323897838593,
-0.02872956171631813,
0.03474569320678711,
... |
<p>I'd like to check the inter-rater agreement between the six raters for the six ordinal variables scored for each of the 24 score sheets passed to each rater (6 ordinal variables per sheet, 24 sheets per rater, 6 raters in this study 6 X 24 X 6). </p>
<p>Which inter-rater agreement test should I run on this ordinal... | g66232 | [
0.025215493515133858,
-0.04025747627019882,
0.011176127009093761,
-0.009464578703045845,
0.005165149923413992,
-0.03228963539004326,
-0.009513542987406254,
0.029928237199783325,
-0.050841111689805984,
-0.04180128499865532,
0.06794840097427368,
0.02026057429611683,
-0.05207017809152603,
-0.... |
<p>I have to analyze the results of a survey. The questions regard different motivators that the interviewees encounter ("I do it to help my colleagues" as a motivator for instance); all the answers are ordinal (1=strongly disagree -> 5=strongly agree) and the aim of this study is to see which factor (or set of factors... | g66233 | [
0.007694927975535393,
0.002742130309343338,
-0.01655719056725502,
-0.02540862001478672,
0.02235613763332367,
-0.023073725402355194,
0.032405804842710495,
0.0036496601533144712,
-0.02041877992451191,
-0.02989525906741619,
0.0682932510972023,
-0.03159823268651962,
0.0176224485039711,
0.02389... |
<p>I'd like to recruit your help in coming up with an Excel-based method to analyse a set of raw ordering data where each item is on its own row. </p>
<p>So, in the data below, order 111 contains two part numbers, ABC and DEF, in quantities of 2 and 3, respectively.</p>
<pre><code>Order Number | Part Number | Quantit... | g66234 | [
-0.020382598042488098,
0.06410839408636093,
-0.005028922576457262,
-0.06443057954311371,
-0.028810715302824974,
-0.10638943314552307,
-0.0008468455635011196,
-0.018486855551600456,
-0.0030432722996920347,
-0.004529227036982775,
0.030880194157361984,
0.026996660977602005,
0.030789414420723915... |
<p>I am new to wavelets.
Currently, I am developing a prediction model using time series data.
I am using the <code>wavelets</code> package in R. I am taking part of the time series, doing a wavelet transformation, and trying to predict the final outcome. </p>
<ol>
<li>I am doing a discrete wavelet decomposition. Ho... | g25173 | [
-0.015918731689453125,
-0.05276019871234894,
0.028015587478876114,
-0.017894405871629715,
0.025266531854867935,
-0.09548550099134445,
0.05121688172221184,
0.04652401804924011,
-0.031890854239463806,
-0.01180532667785883,
-0.04398444667458534,
0.011306493543088436,
0.03361586481332779,
0.01... |
<p>I am currently trying to correct forecast data using Kalman filter (python). I do not know where to start.
I wanted to know how can I do a test to Know if my time series is linear or non linear? Is there a test?</p> | g25174 | [
0.008991585113108158,
-0.05225615203380585,
0.0201004296541214,
-0.022982347756624222,
-0.02986775152385235,
-0.05075206607580185,
0.018939509987831116,
0.012784806080162525,
-0.06617732346057892,
-0.0020097969099879265,
0.018943239003419876,
0.026148473843932152,
0.02139216661453247,
0.03... |
<p>I am not a statistician, so please forgive my lack of precision with terminology in the following background and question.</p>
<p>I have done a fair amount of reading and research about the following, but feel as though I may not be headed in the right direction.</p>
<p>I have a mathematical model for which I woul... | g25175 | [
0.06831832975149155,
-0.022397350519895554,
0.013242891058325768,
0.005126806441694498,
0.0006262278184294701,
0.04231927916407585,
-0.020264627411961555,
0.034537967294454575,
-0.06004146486520767,
0.02080291137099266,
0.016557427123188972,
0.007756778504699469,
0.039832670241594315,
0.04... |
<p>I have a vector of length 300 containing some kind of values (say, scores of a math test). The distribution is not normal.
I want to test if the average score of a small group (30 samples) is significantly different from the mean of all the remaining 470 individuals.
I performed a Welch's t-test obtaining a t-statis... | g66235 | [
0.005222029983997345,
0.02611522376537323,
-0.017744535580277443,
-0.005297262687236071,
-0.037053193897008896,
0.003991972655057907,
0.001811851980164647,
0.011265050619840622,
-0.07091394066810608,
-0.0068292152136564255,
0.011637726798653603,
0.02756408601999283,
0.029595842584967613,
-... |
<p>I wish to sample standard linear Brownian motions on the interval $[0,1]$. I do this by dividing the interval into $n$ equal sub-intervals, deciding $B(0)=0$, and letting $B\left(\frac{k}{n}\right)=B\left(\frac{k-1}{n}\right)+\mathcal{N}\left(0,\frac{\sigma^2}{n}\right)$ for $k\ge 1$, after deciding for some $\sigma... | g66236 | [
-0.052175864577293396,
0.043940480798482895,
-0.007737684529274702,
0.02208510786294937,
-0.026360424235463142,
-0.028597349300980568,
0.0494290292263031,
0.022273870185017586,
0.007216623984277248,
-0.04500989615917206,
-0.017321297898888588,
0.02439838834106922,
0.0022756934631615877,
0.... |
<p>I am trying to do text mining, and seeing the code, I have the whole picture about what it's trying to do about the text.
But the problem is on some specific part of code, I don't know why the format is this way, and what the parameters present. So do you have some suggestions about references or books about R lang... | g66237 | [
0.05619657412171364,
0.013307319022715092,
-0.009490149095654488,
-0.043782129883766174,
0.052042778581380844,
-0.032876066863536835,
-0.002747544553130865,
0.04727612063288689,
-0.050035785883665085,
-0.027257176116108894,
0.020745182409882545,
0.021632974967360497,
0.056540075689554214,
... |
<p>I am in the process of describing my research design for my dissertation and ran into a roadblock. In my design, I am converting 20 y/n responses from 190 participants to two dichotomous groups: 1). Chance level and 2). Above chance level.</p>
<p>If chance level is 50% or 10 responses correct/incorrect, how do I de... | g66238 | [
-0.04218734800815582,
-0.002228973200544715,
-0.015402812510728836,
-0.05113507807254791,
-0.01675053872168064,
0.03120500221848488,
0.06428574025630951,
0.01187195349484682,
-0.017067978158593178,
0.035347677767276764,
0.008850389160215855,
-0.009196870028972626,
-0.005593780893832445,
0.... |
<p>I have two multivariate Gaussians $\mathbf{x} \sim \mathcal{N}(\mu_x, \Sigma_x^2)$ and $\mathbf{y} \sim \mathcal{N}(\mu_y, \Sigma_y^2)$. I assume that the covariances are diagonal.</p>
<p>I am interested in modelling the distribution of their product $a = \mathbf{x}^T\mathbf{y}$, ideally as another Gaussian. Since ... | g66239 | [
-0.014914334751665592,
-0.0075540440157055855,
-0.01540260761976242,
-0.05834907293319702,
-0.01709301955997944,
0.0027555048000067472,
0.010013336315751076,
-0.03767716884613037,
-0.003603229997679591,
0.03835591673851013,
-0.006251850631088018,
0.013234549202024937,
-0.014740432612597942,
... |
<p>What is the geometric standard deviation of a value, which is the result of dividing two independent values, each of which has its own geometric standard deviation ?</p>
<p>It is a frequent situation in science, that the the signal of the machines is in linear relationship to the logarithm of the analysed quantity,... | g66240 | [
0.05317205190658569,
0.02197408117353916,
-0.010925916023552418,
0.0007987535209394991,
0.015377056784927845,
0.011804651468992233,
0.03179853782057762,
0.014541064389050007,
-0.03969096764922142,
0.02136175148189068,
-0.027314865961670876,
-0.013139063492417336,
0.06721650809049606,
-0.04... |
<p>I obtained a graph by comparing two values (chemical elements) and I obtained two general trend lines parallel with each other (one from the black circles/triangles/etc., and the other from the grey ones). How can be explained in terms of graph observations / statistical correlation? There is a bimodal correlation?<... | g66241 | [
0.039586495608091354,
0.02456706389784813,
-0.024201685562729836,
-0.07405894249677658,
0.05686182156205177,
-0.014626292511820793,
0.0058469525538384914,
-0.01311769150197506,
-0.009716367349028587,
-0.06593082845211029,
0.009821624495089054,
0.05121372267603874,
0.06853540986776352,
0.01... |
<p>Non-parametric ANOVA – a hot topic that is unanswered. </p>
<p>There are many questions on this topic online. However, they all seem to end in a debate and no definite answer or clear explanation (that I can relate to my data set). The only good answers I can find seem to relate to one treatment, that was repeated ... | g66242 | [
0.004377948585897684,
-0.02130497619509697,
-0.013154023326933384,
-0.047190990298986435,
0.01200959738343954,
-0.02698317915201187,
0.04408258944749832,
-0.006087282672524452,
-0.04264549911022186,
0.03583141043782234,
0.0010301274014636874,
-0.00032714023836888373,
0.00909391138702631,
0... |
<p>Under mild conditions $\dfrac{\bar{X}-\mu}{\sqrt{\sigma^2/n}}$ approaches the standard normal (where $\sigma^2$ is the process variance, not the marginal variance $\sigma^2_x$).</p>
<p>Why is the denominator not the standard error for the sample mean of dependent data, specifically
$\sqrt{\frac{\sigma_x^2}{n}\times... | g26045 | [
0.012242215685546398,
-0.005347805563360453,
-0.02793951891362667,
0.017420504242181778,
-0.04856167733669281,
-0.0012918111169710755,
0.04315413534641266,
-0.004885156638920307,
-0.013934611342847347,
-0.034974150359630585,
0.02442946471273899,
0.015919165685772896,
-0.035397518426179886,
... |
<p>I'm trying to use mixed-effects modelling to analyse some data. There are a number of variables that I need to specify within the model, two of which are between-participants (<code>x1</code> and <code>x2</code>) and two of which are repeated-measures (<code>z1</code> and <code>z2</code>). I'm interested in individu... | g66243 | [
-0.0447860024869442,
-0.04377461224794388,
-0.01668485626578331,
-0.015065501444041729,
0.012354235164821148,
-0.004108554217964411,
-0.0041666897013783455,
0.015147470869123936,
-0.01861448958516121,
-0.006664392072707415,
-0.04095736891031265,
0.006673838477581739,
-0.0028481148183345795,
... |
<p><strong>I have</strong> data on results of surgical operations:</p>
<ul>
<li>date of operation (in YYYY-MM-DD format)</li>
<li>result of operation (0 for successful operation, 1 for unsuccessful operation) </li>
</ul>
<p>Date is usually used only for case ordering.
<strong>I need to</strong> </p>
<ul>
<li>plot a... | g66244 | [
0.007762134540826082,
-0.015486126765608788,
-0.021468184888362885,
-0.006592946592718363,
-0.035658665001392365,
-0.038511790335178375,
0.04735858365893364,
-0.008371374569833279,
-0.047317951917648315,
-0.012956121005117893,
0.053370073437690735,
0.02428169548511505,
0.08583170175552368,
... |
<p>I have information on the distributions of anthropometric dimensions (like shoulder span) for children of different ages. For each age and dimension, I have mean, standard deviation. (I also have eight quantiles, but I don't think I'll be able to get what I want from them.)</p>
<p>For each dimension, I would like t... | g25180 | [
0.012695258483290672,
0.0033698545303195715,
-0.02287442237138748,
-0.09198284149169922,
-0.06843588501214981,
-0.005089686717838049,
0.008090376853942871,
-0.05917227268218994,
-0.04638522118330002,
0.006442443933337927,
0.041634950786828995,
0.007376610301434994,
0.08606719225645065,
0.0... |
<p>Has anyone attempted time series prediction using support vector regression? </p>
<p>I understand support vector machines and partially understand support vector regression, but I don't understand how they can be used to model time series, especially multivariate time series.</p>
<p>I've tried to read a few papers... | g25181 | [
-0.018661992624402046,
-0.001995693426579237,
0.02645070292055607,
0.0330505445599556,
-0.04835888370871544,
-0.04526737332344055,
0.02959166280925274,
0.06210191175341606,
-0.05754981189966202,
-0.04295627400279045,
0.030446311458945274,
-0.03313308581709862,
0.05686802789568901,
0.026904... |
<p>Suppose $X$ is a random variable with pdf $f_X(x)$. Then the random variable $Y=X^2$ has the pdf </p>
<p>$f_Y(y)=\left\{\begin{array}{ll}\frac{1}{2\sqrt{y}}\left(f_X(\sqrt{y})+f_X(-\sqrt{y})\right) & y \ge 0 \\ 0 & y \lt 0\end{array}\right.$ </p>
<p>I understand the calculus behind this. But I'm trying to ... | g49729 | [
0.04427901282906532,
-0.03721978887915611,
-0.03019404597580433,
-0.07418017089366913,
0.02653043530881405,
0.020356597378849983,
0.04833059012889862,
-0.010404297150671482,
-0.02758479118347168,
-0.024170110002160072,
-0.04165741428732872,
0.04651936888694763,
0.03051210381090641,
-0.0319... |
<p>Basically this is a question if I got the general idea behind the Type II Error right. I’ll set up a little reproducible example:</p>
<p>Given $p_0=0.6$ with an $\alpha$-level of $\alpha=0.1$. As Binomial tests are conservative with respect to $\alpha$ we first calculate (using <code>R</code>) the actual $\alpha$ u... | g25182 | [
0.025957578793168068,
-0.012089423835277557,
0.00974744837731123,
0.03602925315499306,
0.04303249344229698,
-0.010241270065307617,
0.020639680325984955,
-0.025948386639356613,
-0.07666212320327759,
0.0009995680302381516,
-0.05762400105595589,
0.031221378594636917,
-0.01877398043870926,
-0.... |
<p>While I have successfully used R for Cluster Analysis and Correspondence Analysis, I'm new to the use of R-project for Choice-Based Conjoint. </p>
<p>Per recommendations in <a href="http://stats.stackexchange.com/questions/9283/conjoint-packages-for-r">this post</a>, I'm looking at the following [R] Packages for pu... | g48470 | [
-0.011833502911031246,
-0.006133947055786848,
-0.009555251337587833,
-0.018346868455410004,
-0.01459410134702921,
-0.06366933137178421,
-0.019213655963540077,
-0.009884404949843884,
-0.04966166988015175,
0.017321301624178886,
0.052094750106334686,
0.0018095819978043437,
0.021962154656648636,... |
<p>I recently had a client come to me to do a bootstrap analysis because an FDA reviewer said that their errors-in-variables regression was invalid because when pooling data from sites the analysis include pooling data from three sites where two sites included some samples that were the same.</p>
<p><strong>BACKGROUND... | g45421 | [
-0.013956422917544842,
-0.04891602322459221,
0.028504200279712677,
-0.012198354117572308,
0.0007022245554253459,
0.03940238058567047,
0.057131171226501465,
0.01652277633547783,
-0.03425496444106102,
-0.0028248548042029142,
0.035225626081228256,
0.03913161903619766,
0.03363395854830742,
0.0... |
<p>Excuse my ignorance. I tried to look up the questions but couldn't find it. I had a discussion today whether it is possible that a study result will have a p<0.05 yet that would be caused by chance (i.e. a possible underpowered study - if I got all the terms correctly). My thoughts were that if there is a statist... | g37842 | [
0.030706048011779785,
-0.01092379167675972,
0.008790898136794567,
0.006933913100510836,
0.009349373169243336,
-0.03651278838515282,
0.03348703309893608,
0.002030576579272747,
-0.05707507207989693,
-0.0488857664167881,
-0.001450571813620627,
0.03473464399576187,
0.0031000080052763224,
-0.03... |
<p>Recently I posted <a href="http://cs.stackexchange.com/questions/2777/determining-how-similar-a-given-string-is-to-a-collection-of-strings">a question over in CS.SE</a> dealing with methods of classifying data. Essentially the problem is that I have a collection of strings (100's of thousands). Most of these strin... | g66245 | [
-0.019377972930669785,
-0.005093017127364874,
0.005967495031654835,
-0.0703280121088028,
-0.008950570598244667,
-0.04184779152274132,
0.06303319334983826,
0.024505123496055603,
-0.044406164437532425,
-0.007613417226821184,
0.0021688693668693304,
0.04133004695177078,
0.04509510472416878,
-0... |
<p>Do random forest measures of variable importance (mean change of accuracy, mean change of Gini index) take the interactions into account? I think I know how we come up with the variable importance plot (by permuting each of the predictors), and it doesn't seem that random forest captures the interaction. Does anybod... | g66246 | [
-0.015794219449162483,
0.0019355396507307887,
-0.00419836537912488,
-0.03214641287922859,
0.00018667832773644477,
-0.038317665457725525,
-0.013048175722360611,
-0.05354132130742073,
-0.016393927857279778,
0.00583525700494647,
-0.03348016366362572,
0.003800515318289399,
0.015234885737299919,
... |
<p>I ran an SVM against a given data set, and made the following observation: If I change the number of features for building the classifier, the number of resulting support vectors will also be changed. </p>
<p>I would like to know how to explain this kind of scenario.</p> | g66247 | [
0.012742307968437672,
0.01594431698322296,
0.006721161305904388,
-0.006163832265883684,
0.027445465326309204,
-0.04563765600323677,
0.02515030838549137,
0.06669119000434875,
-0.03657497838139534,
-0.08351012319326401,
-0.04713466018438339,
0.0547155924141407,
0.11530791968107224,
0.0685220... |
<p>I need to do a panel regression where my data is proportions for both dependent and one of the independent variables.</p>
<p>I do not have the underlying data for the proportion so I cannot expand the data and use logistic regression.</p>
<p>Any ideas on how to handle this? Poisson regression maybe?</p> | g66248 | [
0.03692867234349251,
-0.0013243731809780002,
0.010661990381777287,
-0.05172131955623627,
-0.036435168236494064,
0.004238888621330261,
-0.04986802488565445,
-0.024279210716485977,
-0.023978305980563164,
-0.0798470601439476,
0.0407864935696125,
-0.023076068609952927,
-0.019506262615323067,
0... |
<p>When I run a binary logistic regression using SPSS 19, the program can analyse seven covariates, but consistently omits the eighth. This occurs regardless of which covariate it is. Is this a limitation of this version of the software, or can someone suggest what I may be doing wrong? </p> | g66249 | [
0.044471219182014465,
-0.013039771467447281,
0.01835465617477894,
-0.08857497572898865,
0.04296739026904106,
0.012421919032931328,
-0.002485990058630705,
0.024797936901450157,
-0.0008488569874316454,
-0.049936264753341675,
0.030298754572868347,
-0.029661940410733223,
0.03280843794345856,
0... |
<p>I'm using the <a href="http://cran.r-project.org/web/packages/robustbase/index.html">robustbase</a> package to run a glm estimation. However when I do it, I get the following error:</p>
<pre><code>Error in solve.default(crossprod(X, DiagB * X)/nobs, EEq) :
system is computationally singular: reciprocal condition... | g66250 | [
0.05295082926750183,
0.004620066843926907,
-0.007533329539000988,
0.0011574876261875033,
0.04618402197957039,
-0.005719315726310015,
0.059021320194005966,
0.03617541119456291,
-0.04402286559343338,
-0.011416763998568058,
-0.03503373637795448,
0.03971487283706665,
-0.003172461874783039,
0.0... |
<p>My knowledge of statistics is limited and I am looking for resources to read on the matter if possible. </p>
<p>Anyways, I am currently trying to estimate a confidence interval for a proportion over time. The specific example pertains to a trader's Win % as he make more trades. My current idea is to take the firs... | g66251 | [
0.04955019801855087,
0.013474264182150364,
-0.02733028680086136,
0.007621176075190306,
-0.06369581818580627,
-0.04011397436261177,
0.029042847454547882,
-0.03720698133111,
-0.02915765531361103,
-0.008985158987343311,
-0.0032570497132837772,
0.057521503418684006,
0.031119439750909805,
-0.03... |
<p>I would like to test if the variation of my response variable is higher for one level of an explanatory variable than for the other. However I am not interested in the total variation, but only variation towards higher values of the response variable.
My model (using the package <code>nlme</code> in R):</p>
<p><co... | g66252 | [
-0.006545622833073139,
-0.0337803028523922,
-0.006630992516875267,
-0.053906217217445374,
-0.0062859454192221165,
0.002870322670787573,
0.013733994215726852,
-0.003192576812580228,
-0.029581641778349876,
-0.03513098135590553,
-0.012813961133360863,
0.035283010452985764,
0.008819719776511192,... |
<p>I am working with principal component analysis (PCA) to have a regression model. Let's say we have 3 variables that we get every month, and so far we gathered 10 months of data. We have built the PCA on the raw data matrix.</p>
<pre><code>p = prcomp(na.omit(rdatat), center=TRUE,scale=TRUE)
loadings=p$rotation[]
p... | g66253 | [
-0.00015287809947039932,
-0.08140147477388382,
-0.0031395854894071817,
-0.059068500995635986,
-0.015598775818943977,
-0.042135272175073624,
0.07860852777957916,
0.015562228858470917,
-0.018648456782102585,
-0.04762914776802063,
0.005022420082241297,
0.06314927339553833,
0.03999990597367287,
... |
<p>This may be a dumb question, and I'm certain I should know this, but let's say I have one variable that has a known metric (e.g., variable A has a mean of .7 and standard deviation of .3). How do I scale a second variable (variable B) to have the same mean and standard deviation? </p>
<p>I know how to make both var... | g49745 | [
0.054703135043382645,
-0.01787671633064747,
-0.02084089070558548,
-0.04239891096949577,
-0.0051359678618609905,
-0.0022870502434670925,
-0.052774012088775635,
-0.00385085865855217,
-0.032634295523166656,
-0.040857359766960144,
0.007728298660367727,
0.01739874854683876,
0.0623771958053112,
... |
<p>I've read that the chi square test is useful to see if a sample is significantly different from a set of expected values.</p>
<p>For example, here is a table of results of a survey regarding people's favourite colours (n=15+13+10+17=55 total respondents):</p>
<pre><code>red,blue,green,yellow
15,13,10,17
</code></... | g66254 | [
0.028379347175359726,
-0.0031160383950918913,
0.027443334460258484,
-0.08184343576431274,
0.023888856172561646,
-0.04122479259967804,
0.001729551120661199,
0.007466382347047329,
-0.0022934703156352043,
-0.02149520069360733,
0.0324275828897953,
0.029061686247587204,
0.02234678529202938,
0.0... |
<p>What are some interesting techniques that can be used to analyze Likert data?</p>
<p>As a frame of reference, I have constructed a survey with about 50 items which are intended to assess the attitudes of the survey participants towards two very broad categories. Each item is on a 5 point scale.</p>
<p>The survey w... | g66255 | [
-0.03266528621315956,
-0.010292714461684227,
-0.007185128051787615,
-0.061573028564453125,
-0.006169694010168314,
-0.015223007649183273,
-0.008152492344379425,
-0.0038459086790680885,
0.01131691224873066,
0.021963104605674744,
0.07430282980203629,
0.01123721618205309,
-0.022203460335731506,
... |
<p>I'm trying to code up the spearman correlation coefficient test of R in C++.</p>
<pre><code>> x = runif(100)
> y = runif(100)
> cor.test(x,y, method="spearman")
Spearman's rank correlation rho
data: x and y
S = 165182, p-value = 0.9306
alternative hypothesis: true rho is not equal to 0
sample estimates... | g66256 | [
0.0053708902560174465,
-0.03545389324426651,
-0.01297696866095066,
-0.06175464764237404,
0.035534512251615524,
0.0010328966891393065,
0.07772131264209747,
0.03403295576572418,
-0.0512440986931324,
-0.002486367477104068,
-0.01044656615704298,
0.039096422493457794,
0.0583929680287838,
0.0207... |
<p>I have come across the following statement:</p>
<blockquote>
<p>A notable feature of the Hierarchical Dirichlet Process is that all Dirichlet Processes' $G_j$ share the same set of atoms and only the atom weights differ. This is a result of the almost sure discreteness of the top-level DP.</p>
</blockquote>
<p>W... | g66257 | [
0.03891006484627724,
0.045785728842020035,
0.0035107461735606194,
-0.0063850837759673595,
0.057630836963653564,
0.02331417053937912,
0.03162841126322746,
0.0011039634700864553,
-0.034377578645944595,
-0.05123045668005943,
-0.08341039717197418,
0.05775809288024902,
-0.011989200487732887,
-0... |
<p>I need your assistance on time series count data. I got some annual time series data I want to run, however the dependent variable is a count (number of deaths) while the independent variables are either continuous or discrete. Ideally count data is modeled using standard Poisson or NB model (mostly its usually cros... | g66258 | [
0.01596645824611187,
-0.032608091831207275,
-0.003165963338688016,
0.024362511932849884,
-0.04974086955189705,
-0.00557436840608716,
0.03933604434132576,
0.031918905675411224,
-0.022075284272432327,
-0.013877429999411106,
-0.0033068673219531775,
-0.021453188732266426,
-0.012840945273637772,
... |
<p>As I understand from this <a href="http://justindomke.wordpress.com/2008/12/12/why-does-regularization-work/" rel="nofollow">link</a> regularization used to reduce overfitting of model.</p>
<ol>
<li>Is overfitting bad when we have really a lot of data? </li>
<li>I don't understand why "very large weights fit the tr... | g66259 | [
0.019503707066178322,
0.09928179532289505,
0.002451471518725157,
-0.03639381751418114,
-0.0008650371455587447,
-0.009053362533450127,
0.053336091339588165,
0.06955648958683014,
-0.06280285120010376,
-0.03910036385059357,
-0.04883406311273575,
-0.02919689752161503,
0.007499552331864834,
-0.... |
<p>I'm new to stats. I want to get clarity about Ljung Box test. Its a omnibus test.</p>
<p>I'm using R to test autocorrelations of a time series. Using below command</p>
<pre><code>Box.test(LogReturns, lag = 10, type = c("Ljung-Box"))
</code></pre>
<p>To test autocorrelations upto lag 10, can I infer with above sin... | g66260 | [
0.02010781690478325,
-0.023808984085917473,
-0.025598015636205673,
-0.09077160805463791,
0.017568767070770264,
-0.03964005038142204,
0.04887409508228302,
0.019982729107141495,
-0.08262062817811966,
-0.06980565935373306,
-0.0009450847865082324,
0.058522023260593414,
0.04677683860063553,
0.0... |
<p>I am conducting <code>Goodness-of-fit</code> test on 2 cities using chi square. </p>
<pre><code> | Males Females
| --------------
Test 1 : Boston | 50000 10000
say chi square = 29.45 with df=1
</code></pre>
<p>Similiarly, </p>
<pre><code> | Males Fe... | g25194 | [
0.021519461646676064,
-0.0015314852353185415,
0.0050617121160030365,
-0.03787313029170036,
0.0034536668099462986,
0.021049587056040764,
0.005493972450494766,
0.00949009694159031,
0.026034168899059296,
0.02847876399755478,
-0.04591190069913864,
0.017969362437725067,
0.05828438326716423,
-0.... |
<p>I am currently studying an M.Sc. in pure mathematics (my dissertation focuses on category/set theory)). However recently I have decided that I wish to transition to a much more applied field. During my undergrad I studied almost all pure courses, with only one statistics module.</p>
<p>I have enrolled in an M.Sc. i... | g66261 | [
-0.013616504147648811,
0.05246151238679886,
-0.006415528245270252,
-0.006177598610520363,
-0.02957758679986,
-0.004087341018021107,
0.003676539985463023,
0.04426884651184082,
0.0006207156111486256,
-0.011195294559001923,
0.03699754178524017,
0.03178917244076729,
0.047706007957458496,
-0.02... |
<p>I discussed recently with one of my colleagues about the Greenhouse-Geisser correction for non-sphericity. I told him first that this correction is very conservative and that it would be more efficient to perform an alternative analysis not relying on the sphericity assumption. He answered that, in his case, the eff... | g66262 | [
0.033185333013534546,
-0.017214272171258926,
-0.003894699504598975,
-0.011880951002240181,
0.007860326208174229,
0.0022573189344257116,
0.1258101761341095,
0.06884167343378067,
-0.06684264540672302,
0.01947057619690895,
0.03045457974076271,
-0.023270782083272934,
0.05129193142056465,
0.042... |
<p>I've seen the following equivalent statements about p-values:</p>
<ul>
<li><p><em>"It is the probability of wrongly rejecting the null hypothesis if it is in fact true."</em> [1]</p></li>
<li><p><em>"The P value or calculated probability is the estimated probability of rejecting the null hypothesis (H0) of a study ... | g66263 | [
0.05175693705677986,
0.014319327659904957,
-0.0006762856501154602,
-0.025995131582021713,
0.03356918320059776,
0.036145683377981186,
0.014610768295824528,
0.047638583928346634,
-0.03715779632329941,
-0.014344779774546623,
-0.0030461230780929327,
0.001493614399805665,
0.057263340801000595,
... |
<p>I have a PMF of some discrete distribution that has been numerically computed.<br>
Note that I do <strong>not</strong> have any <em>samples</em> to work with here, so techniques like Maximum-Likelihood and Expectation-Maximization don't apply. I only have the PMF of the discrete distribution itself, which is simply ... | g66264 | [
0.004510180093348026,
-0.04842532053589821,
0.010957715101540089,
-0.06989946961402893,
-0.007243590895086527,
-0.06159535050392151,
0.018246421590447426,
0.018642278388142586,
-0.06873536109924316,
-0.04126061871647835,
-0.0021690630819648504,
-0.03475141152739525,
0.05222838744521141,
0.... |
<p>I have some questions about penalized Bayesian quantile regression with LASSO and adaptive LASSO penalty: </p>
<ol>
<li>Would you give me a detailed outline for the formula, especially as used in Bayesian inference? </li>
<li>What package in R is easy to use and suitable for this topic?</li>
<li>Would you give me R... | g66265 | [
0.06227560713887215,
-0.07346676290035248,
-0.005656498949974775,
0.0027256039902567863,
0.0020121773704886436,
-0.058753423392772675,
0.05609481781721115,
0.0050451806746423244,
-0.023281076923012733,
-0.017538374289870262,
-0.010724499821662903,
0.042942535132169724,
0.06900269538164139,
... |
<p>The <code>plm</code> function of the <code>plm</code> library in R is giving me grief over having duplicate time-id couples, even when I'm running a model that I don't think should need a time variable at all (see reproducible example below).</p>
<p>I can think of three possibilities:</p>
<ol>
<li>My understanding... | g66266 | [
-0.04248838499188423,
-0.015341547317802906,
-0.02102961204946041,
-0.047575876116752625,
0.08257981389760971,
-0.037837568670511246,
0.03265341371297836,
-0.00441734166815877,
-0.029281949624419212,
0.019411548972129822,
-0.014226562343537807,
0.05037253350019455,
-0.006119331810623407,
0... |
<p>In <a href="http://doingbayesiandataanalysis.blogspot.com/2013/07/decisions-from-posterior-distributions.html" rel="nofollow">Doing Bayesian Data Analysis</a> (link to the <a href="http://www.indiana.edu/~kruschke/DoingBayesianDataAnalysis/" rel="nofollow">book</a>) and <a href="http://www.indiana.edu/~kruschke/BEST... | g66267 | [
0.03560195863246918,
-0.03874611854553223,
-0.01148942206054926,
-0.09025993198156357,
-0.016196176409721375,
-0.012376698665320873,
-0.020172176882624626,
0.0068044159561395645,
-0.048542674630880356,
-0.054820723831653595,
0.013777406886219978,
0.010812499560415745,
0.08287977427244186,
... |
<p>I have a question please. I am working on SmartPLS. The question is regarding variable construct representation. Any variable could have construct including dimensions. For example, the entrepreneurial orientation construct is : risk-taking, pro-activeness, and innovativeness. All the three dimensions are under the ... | g66268 | [
0.009409223683178425,
0.014278982765972614,
0.004938467405736446,
-0.0542173832654953,
-0.05314935743808746,
0.01718604378402233,
0.001648909179493785,
-0.0014724661596119404,
-0.02520674467086792,
-0.015610024333000183,
0.008942004293203354,
0.023363739252090454,
-0.00019494930165819824,
... |
<p>Traditional statistical tests, like the two sample t-test, focus on trying to eliminate the hypothesis that there is no difference between a function of two independent samples. Then, we choose a confidence level and say that if the difference of means is beyond the 95% level, we can reject the null hypothesis. If n... | g49424 | [
0.02792726643383503,
0.009239126928150654,
0.013569420203566551,
-0.021258661523461342,
-0.017338233068585396,
0.013097010552883148,
-0.0069116344675421715,
0.045024458318948746,
-0.045285243541002274,
-0.05385744199156761,
0.0153702013194561,
0.005499837454408407,
0.029109694063663483,
-0... |
<p>Here "stationarity" means the first and second moments don't change over time.</p>
<p>From <a href="http://books.google.com/books?id=_DcYu_EhVzUC&lpg=PA273&ots=LHFXqV45HL&dq=stationary%20have%20a%20rapidly%20decreasing%20autocovariance%20function&pg=PA273#v=onepage&q=stationary%20have%20a%20rapi... | g66269 | [
0.06057918071746826,
-0.07403340935707092,
0.0067930747754871845,
-0.03268684074282646,
0.012419862672686577,
-0.02124297060072422,
0.10546889901161194,
0.01685350202023983,
-0.010126611217856407,
-0.03780856728553772,
0.03662833571434021,
0.044468823820352554,
0.059686269611120224,
0.0190... |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.