question stringlengths 37 38.8k | group_id stringlengths 2 6 | sentence_embeddings listlengths 768 768 |
|---|---|---|
<p>Image below is a Matlab plot from 3-layer perceptron learning with 2 hidden nodes in both hidden layers. Are there simple technique or simple coding to remove or detect these fluctuations during training? </p>
<p>What I've tried only is to reduce step size but I had to compensate that with increasing number of iter... | g17404 | [
0.016190679743885994,
0.03262491151690483,
0.006274315994232893,
-0.0102134570479393,
0.0154064130038023,
-0.002422262914478779,
0.055567577481269836,
0.010166728869080544,
-0.0392565093934536,
-0.006287016905844212,
-0.017521897330880165,
0.022894306108355522,
0.04081198200583458,
0.03907... |
<p>It seems to me that in literature these terms are used synonymously.</p>
<p>Does spatial autocorrelation strictly refer to linear dependence, or does spatial autocorrelation refer to the set of measures of spatial dependence (moran's i,...)?</p>
<p>Do you know of any precise definition of both terms?</p>
<p>Thank... | g61011 | [
0.08153637498617172,
-0.029473641887307167,
0.01994931325316429,
-0.036138635128736496,
-0.03428477793931961,
0.03209001198410988,
0.046253666281700134,
0.01038385834544897,
0.010714194737374783,
-0.029413701966404915,
-0.0049151210114359856,
0.023288879543542862,
0.020088544115424156,
-0.... |
<p>Two related questions from me. I have a data frame which contains numbers of patients in one column (range 10 - 17 patients) and 0s and 1s showing whether an incident happened that day. I'm using a binomial model to regress probability of incident on number of patients. However, I would like to adjust for the fact t... | g61012 | [
0.029094835743308067,
-0.02784712240099907,
0.0019381697056815028,
-0.04226124659180641,
0.05742311850190163,
-0.0369492843747139,
0.03416156396269798,
0.03027169406414032,
-0.03444405272603035,
-0.05084454268217087,
-0.010292429476976395,
-0.006335184443742037,
-0.011764874681830406,
-0.0... |
<p>Let $X$ and $X_{i}$, $i=1,...,n$ be random variables on a probability space $(\Omega , \mathcal F,P)$. Show that the best mean square estimator of $X$ given $(X_{1},...,X_{n})$ is $\hat X =E[X|\sigma(X_{1},...,X_{n})]$</p> | g17409 | [
0.028603708371520042,
-0.038481324911117554,
-0.014240962453186512,
-0.011561112478375435,
-0.0035948213189840317,
-0.06678753346204758,
0.010129034519195557,
0.007627200335264206,
0.00748702697455883,
0.023045562207698822,
0.014857051894068718,
0.0304943285882473,
-0.023369094356894493,
0... |
<p>I have one input series of type 0/1 (it is an intervention time series) and some metric response series. I need to have a look at cross correlations. Normally I would use Box-Jenkins-technique. But now I have to prewhiten an input series which is binary. Can I handle it like a metric one? Does it make sense to look ... | g17410 | [
-0.00862335879355669,
0.012255024164915085,
0.018764270469546318,
-0.06974726915359497,
0.02517690695822239,
0.012490225955843925,
0.08865482360124588,
0.00029457666096277535,
-0.04804374277591705,
-0.00016293226508423686,
0.02151641808450222,
0.0021480682771652937,
0.04808302968740463,
-0... |
<p>I'm writing a paper on making probability estimates, and it's been asserted to me that I should take the median of the estimates given by my participants, rather than the mean. I've been told I should do this because the mean is more affected by sampling error than the median.</p>
<p>Why is this? Is this something ... | g17411 | [
0.039191897958517075,
-0.017679382115602493,
0.00922403484582901,
0.01701703481376171,
0.010035351850092411,
0.018833447247743607,
-0.04860507324337959,
0.05374690890312195,
-0.008237333036959171,
0.013061344623565674,
0.05443933233618736,
-0.012028757482767105,
-0.013339528813958168,
0.01... |
<p>Suppose I want to estimate the correlation between $X\sim N(0,1)$ and $Y$, where $Y \in \{-1,0,1\}$ and is equal to zero for 99 per cent of the sample. Sample size is 10 million.</p>
<p>What are the properties of the Pearson correlation in this instance (bias, usefulness, etc)? Would an alternative correlation esti... | g61013 | [
0.03045375645160675,
-0.028386816382408142,
0.005311169661581516,
-0.060896746814250946,
0.025743594393134117,
-0.04156401380896568,
-0.008884578943252563,
-0.01840147189795971,
0.0061485678888857365,
-0.01647878810763359,
0.051627885550260544,
0.0004068954731337726,
-0.04369878023862839,
... |
<p>I am trying to figure out what kind of analysis is needed to answer this kind of question:</p>
<blockquote>
<p><strong>Is having a positive diagnosis in "D" changing the number of events "E" after the diagnosis?</strong> </p>
</blockquote>
<p>I want to find the ratio between number of events after and before dia... | g61014 | [
0.04255102947354317,
-0.021127691492438316,
-0.019070414826273918,
0.0011343732476234436,
-0.026789255440235138,
-0.07793789356946945,
0.06205975264310837,
0.002414735034108162,
0.006574783939868212,
0.003995405975729227,
0.01989586465060711,
0.04528063163161278,
0.10762268304824829,
0.024... |
<p>I am building a multivariate regression model and trying to use the model to predict a High, Medium, and Low estimated outcome for each individual in a group of people. I am using the 95% confidence interval to get the High/Medium/Low estimates. This means constructing a High, Medium, and Low estimate for each varia... | g61015 | [
-0.01954479143023491,
-0.06540346145629883,
0.008594169281423092,
0.025338130071759224,
-0.015321682207286358,
0.011500157415866852,
0.008041736669838428,
0.050189707428216934,
-0.01780770532786846,
-0.044603634625673294,
-0.0441315732896328,
0.03255264461040497,
0.028312833979725838,
0.02... |
<p>Is it appropriate when forecasting to use $R^2$ as the measure of how well exponential smoothing fits a data set for the purpose of time-series forecasting?</p>
<p>I understand that it is appropriate for regression analysis; could I compare $R^2$ values between a linear regression, logarithmic regression and expone... | g17418 | [
0.02516571246087551,
-0.030138470232486725,
0.012435724027454853,
-0.028016921132802963,
-0.04119805619120598,
-0.03163691237568855,
0.00411137705668807,
-0.0016760638682171702,
-0.06181388348340988,
0.0016693189973011613,
0.046101395040750504,
0.03371579945087433,
0.04046054184436798,
0.0... |
<p>The density function of a random variable x is $f(x)=ke^{-2x^{2}+10x}$. Find the upper 5% point of the distribution of the means of the random sample of size 25 from the above population.</p>
<p>I need hints to pursue this. My thoughts: </p>
<ol>
<li><p>Assume normal population. Find the value of k by integrating ... | g17419 | [
-0.0062720393761992455,
-0.020888790488243103,
-0.02822858653962612,
-0.06116683408617973,
-0.03530114144086838,
-0.05610841140151024,
0.037733376026153564,
-0.03201892226934433,
-0.05420058220624924,
0.003285926766693592,
-0.0246120672672987,
0.003806362859904766,
0.013502709567546844,
0.... |
<p>Various descriptions on model selection on random effects of Linear Mixed Models instruct to use REML. I know difference between REML and ML at some level, but I don't understand why REML should be used because ML is biased. For example, is it wrong to conduct a LRT on a variance parameter of a normal distribution m... | g61016 | [
0.004967835731804371,
-0.04562631994485855,
0.01928752101957798,
-0.019642474129796028,
0.03393226116895676,
0.0017815815517678857,
0.050973426550626755,
0.013190648518502712,
-0.025220299139618874,
-0.024097559973597527,
0.0028385703917592764,
0.028132714331150055,
0.041071098297834396,
0... |
<p>I have 2 samples, A and B. I subjected both samples to extraction and got the amount of yield (the dependent variable). </p>
<p>I just want to see if there is a significant difference between the yield for A and B.</p>
<p>Each sample had 3 replicates.</p>
<p>Sample A:</p>
<pre><code>0.003,0.0029, 0.003
</code></... | g61017 | [
-0.007955895736813545,
-0.006881447043269873,
-0.0036073685623705387,
-0.010448439046740532,
-0.01598798856139183,
-0.011877885088324547,
0.032033100724220276,
0.008937418460845947,
-0.06930509209632874,
-0.039060384035110474,
0.013918513432145119,
-0.01378403790295124,
-0.035179510712623596... |
<p>What does "model-based" mean for multivariate statistics?
E.g. <a href="http://onlinelibrary.wiley.com/doi/10.1111/j.2041-210X.2012.00190.x/full" rel="nofollow">mvabund– an R package for model-based analysis of multivariate abundance data</a>.</p>
<p>How is "non-model-based multivariate statistics" then?</p>
<p>Th... | g61018 | [
0.03576895222067833,
-0.07994213700294495,
-0.021371621638536453,
-0.013930345885455608,
0.04305141046643257,
-0.016499370336532593,
0.01854507066309452,
-0.0042563374154269695,
0.03131118416786194,
0.020469503477215767,
0.006189814768731594,
-0.028064565733075142,
0.09528670459985733,
0.0... |
<p>Are multivariate statistics and machine learning solving the same problems?
I saw that their books are about the same topics, so I have the impression that they are solving the same problems and probably using the same methods.</p>
<p>What are their relations and differences?</p>
<p>Can machine learning solve the ... | g61019 | [
0.03108114004135132,
-0.01629786379635334,
0.025356614962220192,
-0.0169687420129776,
-0.010878825560212135,
-0.012293843552470207,
-0.013327726162970066,
0.02458946406841278,
-0.01813752017915249,
-0.017475372180342674,
0.03352620080113411,
-0.030332524329423904,
0.04755129665136337,
-0.0... |
<p>I have come about a quote in Groves & Lyberg (2010, p. 859) saying that "(...) both interpenetration and reinterview designs are required to estimate these terms" (referring to estimation of response deviations, which are the variance component in the total variance of a mean that is not due to sampling variance... | g61020 | [
0.04599183052778244,
-0.01728556863963604,
-0.005334259010851383,
-0.044233765453100204,
-0.005810422822833061,
0.007380859926342964,
0.03652564436197281,
0.018220311030745506,
-0.04698977246880531,
-0.010922245681285858,
0.01168764941394329,
0.009182789362967014,
-0.04096416011452675,
0.0... |
<p>Is it possible to train a neural network N times, using backpropogation and then average the weights learned to produce a more accurate classifier?</p>
<p>My tests are indicating no, but I'm unsure if it is an implementation error?</p>
<p>Thank you</p> | g17424 | [
-0.00250625959597528,
-0.014628440141677856,
0.01533867884427309,
-0.025403698906302452,
0.028713025152683258,
-0.06587262451648712,
0.029300417751073837,
0.03032740391790867,
-0.07001040130853653,
0.03482039272785187,
-0.029546644538640976,
0.02085665985941887,
0.003053507301956415,
0.037... |
<p>Does anyone know of a function or R package that can help me turn z scores into percentile scores?
The final goal is to classify or rank a group of respondents into four categories based on the heights of their z scores (20% lowest scores, 30%, 30%, 20% highest scores).</p>
<p>Any ideas? Many thanks in advance!</p> | g47683 | [
0.001171474577859044,
-0.058229438960552216,
-0.007135074585676193,
-0.023649366572499275,
-0.015786204487085342,
-0.013095881789922714,
0.031051507219672203,
0.0006096605793572962,
-0.058165136724710464,
-0.01823851466178894,
0.0218829158693552,
-0.010530734434723854,
0.043011657893657684,
... |
<p>I understand that the Wald test for regression coefficients is based on the following property that holds asymptotically (e.g. Wasserman (2006): <a href="http://rads.stackoverflow.com/amzn/click/1441923225" rel="nofollow">All of Statistics</a>, pages 153, 214-215):
$$
\frac{(\hat{\beta}-\beta_{0})}{\widehat{\operat... | g61021 | [
0.031831804662942886,
-0.036515381187200546,
-0.027148550376296043,
-0.01415120717138052,
0.026652920991182327,
-0.03420913591980934,
0.061526428908109665,
0.04544949531555176,
-0.041428133845329285,
0.0004752906388603151,
-0.012345523573458195,
0.030400430783629417,
0.0549960620701313,
0.... |
<p>(1) When doing PCA, do you assume the variables to be bell-shaped? Say if I have a bunch of variables, some are bell-shaped but some have characteristic long (right) tails (highly skewed and asymmetric with the median close to the minimum and and a few extremely large values). Should I do log transformation on those... | g17426 | [
0.011360223405063152,
-0.049990590661764145,
0.004467020742595196,
-0.05384688824415207,
0.04287901520729065,
-0.03401435166597366,
0.044048599898815155,
0.013274859637022018,
-0.0024514230899512768,
-0.0365133062005043,
-0.03194975480437279,
0.07262247800827026,
-0.014575553126633167,
0.0... |
<p><a href="http://en.wikipedia.org/wiki/Correlation_clustering" rel="nofollow">Correlation Clustering</a> : Given a signed graph where the edge label indicates whether two nodes are similar (+) or different (−), the task is to cluster the vertices so that similar objects are grouped together. </p>
<p><a href="http:/... | g47120 | [
0.03039807453751564,
0.00013174244668334723,
0.020370667800307274,
-0.04272837191820145,
0.008259603753685951,
-0.05741168558597565,
0.03447506204247475,
0.016684358939528465,
0.013877352699637413,
0.007998575456440449,
0.04274751991033554,
0.005158432759344578,
0.0694473385810852,
0.02720... |
<p>Lets imagine I have estimated the following simple linear regression model:
$y_{i} = 10 + 0.5x_{i} + \varepsilon_{i} $, and want to work out the counter-factual, or what would $ y_{i}$ be in the absence of $ x_{i}$.</p>
<p>The most simple example of this is a simple treatment control case. So $x_{i} = T_{i}$ and $T... | g39623 | [
0.08881516754627228,
0.0016329203499481082,
-0.04357678443193436,
-0.03611193597316742,
0.03945893794298172,
0.01606348343193531,
0.05341557040810585,
-0.003251885762438178,
-0.014065650291740894,
-0.04074644669890404,
-0.02904168702661991,
0.004286594223231077,
0.014104526489973068,
-0.01... |
<p>I have a set of time series $\mathcal{Y}$, and a test time series $T$ for which I need to find the closest matching time series $Y_i \in \mathcal{Y}$. This has to be done online, i.e., $T$ is a stream of measurements and the detection has to happen as each measurement of $T$ is taken. The time series in $\mathcal{Y}... | g27080 | [
0.041256070137023926,
-0.013897554948925972,
-0.01001516543328762,
-0.014406182803213596,
-0.07058212161064148,
-0.03258643299341202,
0.003985774237662554,
-0.044344376772642136,
-0.043459322303533554,
0.02497253380715847,
-0.01957264170050621,
0.027378985658288002,
0.02684858813881874,
-0... |
<p>I'm prototyping my own Naive Bayes bag o' words model, and I had a question about calculating the feature probabilities.</p>
<p>Let's say I've got two classes, I'll just use spam and not-spam since that's what everyone uses. And let's take the word "viagra" as an example. I have 10 emails in my training set, 5 spam... | g17431 | [
-0.017904309555888176,
-0.004360883962363005,
0.023516424000263214,
-0.04136789217591286,
0.023745760321617126,
-0.007917577400803566,
0.026814283803105354,
0.10426409542560577,
-0.0489845797419548,
0.021685928106307983,
0.003088562749326229,
0.038249678909778595,
0.027759656310081482,
0.0... |
<p>In R, I've plotted the half-normal residuals for a few different models, i.e.</p>
<pre><code>halfnorm(residuals(model_object)))
</code></pre>
<p>I notice that one plot takes a distinct S-shape (i.e. it's Sigmoidal) and has an area of discontinuity (a gap) in the center. I'm curious about what such a result means.<... | g61022 | [
-0.01442550029605627,
-0.0386069193482399,
-0.02836776152253151,
-0.017679771408438683,
-0.03441474959254265,
-0.004939247388392687,
0.06009869650006294,
-0.012555275112390518,
-0.024491073563694954,
-0.02283010631799698,
-0.019102150574326515,
0.02462588995695114,
-0.0006559530738741159,
... |
<p>I'm confused with my data I'm currently playing with.</p>
<p>I have a data set which holds 58 attributes in 10000 instances. Attributes are 56 float values typically within 0 to 1. Then there is nominal attribute which tells "data class". Last one is result of data, which is nominal attribute with 3 different value... | g61023 | [
0.022073032334446907,
-0.008380423299968243,
0.0024550308007746935,
-0.06908885389566422,
0.021483704447746277,
-0.01807265356183052,
0.04188069701194763,
0.007655918598175049,
-0.01004707533866167,
-0.0009509532246738672,
0.039059266448020935,
0.06560163199901581,
0.030098367482423782,
0.... |
<p>I am doing Prenatal (before delivery) and Postnatal (after delivery) depression assessment (2 time points).<br>
Dependent variable is Depressed/Non depressed mother on a measure of depression.<br>
When as there a number of predictor variables both continues and categorical in nature.<br>
Clearly speaking I am using... | g61024 | [
-0.00376821868121624,
-0.03258495777845383,
-0.009171968325972557,
-0.023074356839060783,
-0.033663392066955566,
0.00136176694650203,
0.013229118660092354,
-0.036298561841249466,
-0.10399386286735535,
-0.011498672887682915,
-0.07626694440841675,
0.0346212312579155,
0.03082028403878212,
0.0... |
<p>This is my first question!</p>
<p>My firm takes boxes of documents, preps them (removing staples, taping torn documents), and then scans the documents. I want to calculate what effect staples and torn documents have on the time it takes to prep a box of documents. </p>
<p>We measured a series of boxes for: the # o... | g61025 | [
0.011874569579958916,
-0.006412488408386707,
-0.007341237738728523,
-0.06319848448038101,
0.002454557688906789,
-0.0734231099486351,
0.013424237258732319,
0.03456556051969528,
0.02652229741215706,
-0.021984102204442024,
-0.008568580262362957,
-0.033072877675294876,
0.042498379945755005,
-0... |
<p>What relation are between minimum contrast estimate and minimum distance estimate?</p>
<p>If I understand correctly, these two are different methods? or are they equivalent?</p>
<p>Thanks and regards!</p>
<hr>
<p>Minimum distance estimate from <a href="http://en.wikipedia.org/wiki/Minimum_distance_estimation" re... | g61026 | [
0.008502716198563576,
-0.05900360643863678,
-0.00974898599088192,
-0.023115279152989388,
-0.01370577234774828,
-0.03734081983566284,
-0.03703157231211662,
-0.009231070056557655,
-0.032791201025247574,
-0.05543460696935654,
-0.01712772250175476,
0.05137786641716957,
0.015408509410917759,
0.... |
<p>I'm trying to generate an R function that keeps relevant variables based on their absolute t-value (or p, whichever is easier in code).</p>
<p>Basically what I want is to run one regression (1), retain all variables that are significant (based on the t-value, or p). Then run another regression (2), retain all varia... | g37686 | [
0.024007871747016907,
-0.06427233666181564,
0.004977425094693899,
-0.024126984179019928,
0.016869015991687775,
-0.02314121089875698,
0.017066946253180504,
0.032252002507448196,
-0.06863228231668472,
0.0035481108352541924,
0.000894212513230741,
0.03903257101774216,
0.03344691917300224,
0.01... |
<p>If I plot some data in function of a categorical variable in R, I get the standard boxplot. However, the boxplot displays non-parametric statistics (quantiles) that don't seem appropriate for normally distributed data.</p>
<p>What is the equivalent of the boxplot for normally distributed data (ideally, something ba... | g47128 | [
0.008309286087751389,
0.007208377588540316,
-0.038663141429424286,
-0.02394918166100979,
-0.02366543933749199,
0.032571129500865936,
-0.00017466234567109495,
-0.04992268979549408,
-0.05523304641246796,
-0.042582783848047256,
0.024287352338433266,
-0.01660807617008686,
0.019341295585036278,
... |
<p>I am not a stats person. </p>
<p>The world bank has data giving PPP (personal purchasing parity, or something like that) for quintiles (actually first 10%, second 10%, 2nd, 3rd, 4th 20%, 9th 10% and 10th 10%) of a country's population.</p>
<p>I've been reading a good deal about the Gini index and also modeling in... | g56 | [
0.036009322851896286,
0.03292274847626686,
-0.0034958948381245136,
-0.07618390023708344,
0.0024164137430489063,
-0.024295033887028694,
-0.04681796580553055,
-0.03528246656060219,
-0.028878994286060333,
-0.029487093910574913,
0.01259005255997181,
-0.046071793884038925,
0.06411954760551453,
... |
<p>I designed a field experiment with 4 independent factors but data is not normal and heteroscedastic. Friedman test (agricolae package) from R only fits for rbd. Can anybody suggest how to analyze my data please?</p>
<p>Many thanks.</p> | g61027 | [
0.022897640243172646,
-0.0037896756548434496,
-0.014438868500292301,
0.021391311660408974,
0.016387371346354485,
-0.014140762388706207,
0.032277729362249374,
0.007902467623353004,
-0.03264019265770912,
-0.01674552448093891,
0.027079405263066292,
0.04084173962473869,
0.0038442304357886314,
... |
<p>I am trying to evaluate the elasticity of prices of some goods. I am concerned about the gaussianity of the noise in the prices. With non gaussianity I am referring to the non existence of the firt/second moment fo the distribution of the error. Is there a way to fit linear model without the assumption of gaussianit... | g61028 | [
0.03323422744870186,
-0.03960782289505005,
0.00014708434173371643,
-0.05286569520831108,
0.031503695994615555,
0.005029287189245224,
-0.01701548881828785,
-0.013984146527945995,
-0.027465349063277245,
0.03412676975131035,
-0.021843215450644493,
-0.010865764692425728,
0.019888658076524734,
... |
<p>I've got a dataset where someone counted birds in the breeding season over 10 years. For each year (x site), we want to see how reduced sampling might affect our ability to detect a trend. So to that end, I have simulated various datasets from the original where we cut down sampling to once every 45 days (and 60, 90... | g37795 | [
-0.035624850541353226,
-0.04191625118255615,
-0.012453011237084866,
-0.03699284791946411,
-0.01896166428923607,
0.0038394227158278227,
0.004668090492486954,
0.02870442345738411,
-0.08074824512004852,
-0.04652916640043259,
-0.01896447315812111,
0.07368067651987076,
0.03607065603137016,
-0.0... |
<p>Suppose I have a two-way factorial design and perform a linear model analysis such as (using <em>R</em>):</p>
<p><code>utils::data(npk, package = "MASS")</code></p>
<pre><code>lm(yield ~ block*P, npk)
</code></pre>
<p>Here, the intercept is the mean of yield of the first level of factors <em>block</em> (with lev... | g61029 | [
0.015178120695054531,
-0.03563302755355835,
-0.005614091642200947,
-0.018046094104647636,
0.03873395174741745,
-0.06552844494581223,
0.04215628281235695,
-0.005216848570853472,
-0.03866560757160187,
-0.06354116648435593,
-0.03740725293755531,
0.01575079746544361,
0.054607097059488297,
-0.0... |
<p>For a unimodal distribution that is moderately skewed, we have the following empirical relationship between the mean, median and mode:
$$
\text{(Mean - Mode)}\sim \text{3(Mean - Median)}
$$
How was this relationship derived? Did Karl Pearson plot thousands of these relationships before forming this conclusion, or... | g61030 | [
-0.020243562757968903,
-0.045369479805231094,
-0.020058143883943558,
-0.039030157029628754,
-0.023615900427103043,
0.026586512103676796,
-0.034409280866384506,
-0.003544649574905634,
0.009801383130252361,
-0.0013508389238268137,
-0.009786023758351803,
-0.011743830516934395,
0.068492539227008... |
<p>I am new to R and I use a script I do not completely understand. It preprocesses a dataset for data mining. At one point, the data (stored in <code>fil</code>) should be centered and scaled and the NA values are replaced by values calculated with <code>knnImpute</code>.</p>
<pre><code>preProcValues <- preProcess... | g61031 | [
0.03309321403503418,
-0.029822679236531258,
-0.011086808517575264,
-0.04709862917661667,
0.029405150562524796,
-0.03979748487472534,
-0.0023902072571218014,
-0.004332671407610178,
-0.07268723100423813,
-0.020598042756319046,
-0.0456412136554718,
0.045493219047784805,
0.04425307363271713,
0... |
<p>I have a sample of 20 years, I want to perform multiple regression analysis to estimate economic growth. I have 9 independent variables, but because my sample is small i get insignificant results. I do not have data to maken it a sample of 100 years or anything near that. What can I do? Can I incorporate the sample ... | g61032 | [
0.02596561796963215,
0.017511984333395958,
-0.008907314389944077,
-0.06814710795879364,
-0.08292203396558762,
0.0044169193133711815,
-0.023515794426202774,
0.022290343418717384,
-0.03386801481246948,
-0.055303364992141724,
0.005775005090981722,
0.00798710621893406,
0.016321061179041862,
0.... |
<p><strong>1-</strong> How can I check if a set of data can be assumed as IID data?
I'm not so familiar with statistics, but I guess I should look at the first lag of autocorrelation for independent distribution. Have no idea about identical distribution condition!</p>
<p><strong>2-</strong> It seems that I was not cl... | g61033 | [
-0.0009872656082734466,
-0.03715894743800163,
-0.011808853596448898,
-0.044464245438575745,
-0.01382279023528099,
-0.006387649103999138,
0.018634365871548653,
-0.002748049795627594,
-0.05165329948067665,
-0.02073012851178646,
-0.03423331305384636,
0.05321440473198891,
0.0029793530702590942,
... |
<h3>The situation</h3>
<p>Some researchers would like to put you to sleep. Depending on the secret toss of a fair coin, they will briefly awaken you either once (Heads) or twice (Tails). After each waking, they will put you back to sleep with a drug that makes you forget that awakening. When you are awakened, to wh... | g61034 | [
-0.0017481081886216998,
0.031979743391275406,
-0.0134598882868886,
-0.0582723543047905,
0.021221619099378586,
0.03676692396402359,
-0.005176570266485214,
0.015062130987644196,
0.04256407171487808,
0.005480440333485603,
-0.007019015960395336,
-0.013679021038115025,
0.056151553988456726,
-0.... |
<p>I'm using AIC (Akaike's Information Criterion) to compare non-linear models in R. Is it valid to compare the AICs of different types of model? Specifically, I'm comparing a model fitted by glm versus a model with a random effect term fitted by glmer (lme4).</p>
<p>If not, is there a way such a comparison can be don... | g17444 | [
0.0048897759988904,
-0.03643776848912239,
0.008215750567615032,
-0.019423965364694595,
-0.004963486921042204,
-0.014100132510066032,
0.03171944245696068,
-0.03581773489713669,
-0.09151653200387955,
0.0378166101872921,
0.06155645474791527,
0.011732427403330803,
0.03413032740354538,
-0.01009... |
<p>I want to implement (in R) the following very simple Dynamic Linear Model for which I have 2 <strong>unknown time varying parameters</strong> (the variance of the observation error $\epsilon^1_t$ and the variance of the state error $\epsilon^2_t$).</p>
<p>$
\begin{matrix}
Y_t & = & \theta_t + \epsilon... | g61035 | [
0.05421983450651169,
-0.030836325138807297,
0.0001959311484824866,
0.016379963606595993,
0.00019534060265868902,
-0.08809611946344376,
0.045392826199531555,
0.003357107052579522,
-0.030709942802786827,
0.04171278327703476,
-0.014483307488262653,
0.04493286460638046,
0.06793689727783203,
0.... |
<p>Suppose $X \sim N(\mu, \sigma^2)$. After $n$ independent draws $\bar{X} \sim N(\mu, \frac{\sigma^{2}}{n})$. I am assuming that each draw contains $n$ numbers? Because if each draw only had one number then we would only have one mean.</p> | g17448 | [
-0.02112581953406334,
0.046552181243896484,
-0.01957489363849163,
-0.02567681297659874,
0.011037236079573631,
-0.006432883441448212,
-0.01748024858534336,
-0.04333518072962761,
-0.04284316673874855,
-0.046466391533613205,
-0.07588307559490204,
0.02232716605067253,
0.01785069890320301,
0.01... |
<p>My question is about calculation of confidence interval (CI) for odds ratio (OR) from a SAS output of a logistic regression model for a different reference category without running the SAS program again. I’ve run SAS logistics modeling dichotomized income level (low coded as 1 versus high coded as 0) with 4 dummy co... | g17450 | [
0.013788892887532711,
-0.06001008674502373,
-0.02182726375758648,
-0.037875231355428696,
-0.016494465991854668,
-0.004484219942241907,
0.004235335160046816,
0.005490332376211882,
-0.05252448841929436,
-0.003203389700502157,
0.019567370414733887,
0.055438604205846786,
0.07278501987457275,
-... |
<p>first time asking question here so I hope I will not mess up.</p>
<p>I am in the process of calculating the sample size for a study that utilizes an independent <em>t</em>-test design: comparing some outcome before and after a certain policy, subjects in the pre and post periods are not linked. Simply put, the stud... | g61036 | [
-0.000820023356936872,
0.003955346532166004,
-0.006572520826011896,
-0.02630838192999363,
-0.06353866308927536,
-0.03797977417707443,
-0.024782462045550346,
-0.026623059064149857,
-0.022148452699184418,
-0.03178643062710762,
0.04910982400178909,
0.00018123221525456756,
0.06535695493221283,
... |
<p>I recently came across the following paper: "<a href="http://www.cs.huji.ac.il/~shais/papers/ShalevTewari09.pdf" rel="nofollow">Stochastic Methods for $\ell_1$ Regularized Loss Minimization</a>" by Shai Shalev-Shwartz and Ambuj Tewari, ICML 2009.</p>
<p>In the paper, the authors propose a modification of the coord... | g61037 | [
0.04306016489863396,
-0.036344755440950394,
-0.008577419444918633,
0.016307547688484192,
0.039253976196050644,
-0.04645034298300743,
0.027610989287495613,
0.02865232527256012,
-0.029916925355792046,
0.026482461020350456,
0.009503613226115704,
0.03319248557090759,
0.09186194837093353,
0.051... |
<p>Given a machine learning model built on top of scikit-learn, how can I classify new instances but then choose only those with the highest confidence? How do we define confidence in machine learning and how to generate it (if not generated automatically by scikit-learn)? What should I change in this approach if I had... | g17454 | [
-0.024972647428512573,
-0.053995128720998764,
0.017524614930152893,
0.0007523824460804462,
0.03502678498625755,
0.03699077293276787,
-0.04626874625682831,
0.025323042646050453,
-0.05485457554459572,
-0.03215464949607849,
0.01991928555071354,
0.03489124774932861,
0.05294143781065941,
0.0121... |
<p>Is it acceptable to not include high-order interactions (3-way and above) in the model when they are not of interest and not part of the hypothesis that is being tested?</p>
<p>NB. I am not talking about model reduction when a full model was fitted and higher interactions later excluded. I am asking about not inclu... | g61038 | [
0.04451516270637512,
-0.021742314100265503,
0.017136970534920692,
-0.031244928017258644,
0.028930487111210823,
0.05166717991232872,
0.03346122428774834,
0.020380839705467224,
0.017521919682621956,
-0.0012332525802776217,
0.006505799945443869,
-0.026208464056253433,
-0.04241374507546425,
0.... |
<p>A short entry on the NY Times website provides the <a href="http://takingnote.blogs.nytimes.com/2014/02/10/facts-figures-pizza-consumption/">Facts and Figures</a> of pizza consumption in the United States. I have a casual interest in how statistics are used (or abused) to provide information to general audiences, a... | g61039 | [
0.011992167681455612,
0.1192457526922226,
-0.002112693851813674,
0.030733564868569374,
-0.04986492544412613,
-0.043931957334280014,
0.003682682989165187,
0.03896370157599449,
-0.0024723068345338106,
-0.017010021954774857,
-0.016271675005555153,
-0.01178997103124857,
0.048974379897117615,
0... |
<p>If the continuous variables are measured with error, can the use of dummy variables mitigate the problem? For instance, IQ measures intelligence with error. So will using a dummy of high, medium, low IQ mitigate the measurement error problem? Thanks!</p> | g49372 | [
-0.002331814728677273,
-0.006391658913344145,
0.005226569250226021,
-0.048008184880018234,
-0.017231471836566925,
0.026569252833724022,
0.010883287526667118,
-0.0002654666604939848,
-0.028228547424077988,
0.01669580489397049,
-0.025496121495962143,
0.007856007665395737,
-0.06308960914611816,... |
<p>I have a toy dataset and want to eval the AUC - ROC with bootstrap</p>
<pre><code> set.seed(117)
test <- c(rnorm(70, 40, 10), rnorm(30, 55, 10))
dx <- c(rep(0, 65), rep(1,35) )
df <- data.frame(cbind(test, dx))
r <- 1000
boot.f <- function(d, i){
data <- d[i,]
p... | g61040 | [
-0.031222978606820107,
0.04730457067489624,
0.003692306112498045,
-0.07026205211877823,
0.0479743555188179,
-0.038716189563274384,
0.04840344190597534,
0.006171822547912598,
-0.0691106840968132,
-0.03854260966181755,
-0.0315362885594368,
0.024218427017331123,
0.08130641281604767,
0.0359799... |
<p>I'm trying to fit a model with the function <code>glmer</code> (<code>lmer4</code> 1.1-7 package) in R using REML but I just get an error saying <code>extra argument(s) ‘REML’ disregarded</code> (see below).
How else can I fit it with REML to optimize the random effects structure with this package?</p>
<pre><code>a... | g27190 | [
0.03592657297849655,
-0.04554159939289093,
-0.017287075519561768,
-0.03431152552366257,
0.011373710818588734,
-0.004713276866823435,
0.012356643564999104,
0.01593605801463127,
-0.062071237713098526,
-0.018031880259513855,
0.003152356715872884,
-0.016695348545908928,
-0.001864259596914053,
... |
<p>Let's say I have to sample from a pdf $\pi(x) = 3x^3+\frac{3}{4}x^2, 0 \le x \le 1$. I know we have to pick some pdf $g(x)$ such that $cg(x) \ge \pi(x)$ for all x. The only thing that came to mind was using $g(x) = 1$ with $c = 3.75$. So $cg(x) = 3.75$. No better distributions come to mind that are easy to sample fr... | g61041 | [
0.032235585153102875,
0.0018047537887468934,
-0.011896002106368542,
-0.06160439923405647,
-0.04500332102179527,
-0.020842865109443665,
0.0228747446089983,
0.0075654685497283936,
-0.04894722253084183,
0.0053533269092440605,
0.03431118652224541,
-0.01953204907476902,
0.05096627026796341,
-0.... |
<p>Breusch-Pagan rejects the H0 on this residuals:</p>
<pre><code>> length(model$residuals)
[1] 515959
> summary(model$residuals)
Min. 1st Qu. Median Mean 3rd Qu. Max.
-205.000 -4.420 -0.451 0.000 4.130 196.000
> quantile(model$residuals, seq(0, 1, 1/10))
0% ... | g27193 | [
-0.022807758301496506,
-0.04817356914281845,
0.017406931146979332,
-0.02225871942937374,
-0.035851314663887024,
0.024322059005498886,
0.003966670483350754,
-0.0244497898966074,
-0.03218475729227066,
0.010639606043696404,
0.0015453881351277232,
0.05096924304962158,
-0.0016642004484310746,
0... |
<p>How can I find if I should t-test or chi-squared test if I am given a problem like the following? </p>
<p>Consider testing $H_0: \sigma^2_X = \sigma^2_Y$ against $H_1: \sigma^2_X ≠ \sigma^2_Y$ from two independent samples from normal populations with unknown means $\mu_X$ and $\mu_Y$ and standard deviations $\sigma... | g61042 | [
0.04379676654934883,
-0.026934895664453506,
-0.002863390604034066,
-0.0076082427985966206,
0.008267931640148163,
-0.07328388094902039,
0.005705887917429209,
0.01463546697050333,
-0.021644053980708122,
0.0010383909102529287,
-0.0172980148345232,
0.024683469906449318,
0.010883143171668053,
0... |
<p>I'm actually "Getting started" with RapidMiner (RM).
I'm an R expert but totally newbie to RM. The problem involved is analysing and forecasting the dispersion of multivariate timeseries (in finance). The R codes we have are very difficult for economists. I found RM as a real alternative because of its visual "self-... | g61043 | [
0.010547097772359848,
-0.047972436994314194,
-0.013902805745601654,
-0.012060793116688728,
-0.026581481099128723,
-0.0871715247631073,
0.027839625254273415,
-0.01785573922097683,
-0.06332200765609741,
0.02939719706773758,
0.03427305445075035,
0.029841024428606033,
0.09182897210121155,
-0.0... |
<p>My problem is that I have weekly data from 2008, 2009 and 2010 but the number of weeks in each of these years are not the same since in we (in Denmark) code the last week in 2009 as 53. This means that I have 52 weeks in 2008 and 2010 but 53 weeks in 2009. Is there some way to make R understand this and treat the ti... | g408 | [
0.016207344830036163,
-0.014509778469800949,
-0.001299123978242278,
-0.09057125449180603,
-0.051454007625579834,
-0.013178035616874695,
0.0542369969189167,
0.00971148069947958,
0.008357568643987179,
-0.01730242557823658,
0.039037495851516724,
-0.0011882453691214323,
0.08101445436477661,
-0... |
<p>I have performed a repeated measures ANOVA in R, as follows:</p>
<pre><code>aov_velocity = aov(Velocity ~ Material + Error(Subject/(Material)), data=scrd)
summary(aov_velocity)
</code></pre>
<ul>
<li>What syntax in R can be used to perform a post hoc test after an ANOVA with repeated measures?</li>
<li>Would Tukey... | g49523 | [
0.03224065899848938,
-0.03585183992981911,
-0.00809890404343605,
-0.05014825239777565,
-0.04391337186098099,
-0.03694670647382736,
0.03113425523042679,
0.025129955261945724,
-0.04747658595442772,
0.029977377504110336,
-0.03308301791548729,
0.0315554141998291,
-0.03055419959127903,
0.031597... |
<p>I use finite mixture models. For two sets $A$ and $B$ of starting values (the initial guess) I get the following values of $Q(\bf{\hat{\Theta}})$ function and $\log L(\bf{\hat{\Theta}})$:</p>
<p>Set $A$: $Q(\bf{\hat{\Theta}_A})=110$ and $\log L(\bf{\hat{\Theta}_A})=7$</p>
<p>Set $b$: $Q({\bf{\hat\Theta}_B})=78$ an... | g17462 | [
-0.004685088526457548,
-0.05870434269309044,
0.007782754488289356,
0.012245327234268188,
0.04534823074936867,
-0.007115603424608707,
0.06926462054252625,
0.06024366617202759,
-0.0423097126185894,
0.0026552011258900166,
-0.07014409452676773,
0.00885096751153469,
0.03953554853796959,
0.05280... |
<p>We are wondering what sufficiency in the Lehmann Scheffe Theorem is needed for.
Our reasoning was:</p>
<ol>
<li>If an unbiased estimator is uncorrelated with all unbiased estimators of 0, it is UMVUE</li>
<li>If the estimator is from a complete family, it is uncorrelated with all unbiased estimators of 0</li>
<li>... | g47152 | [
0.06267246603965759,
-0.0053926995024085045,
0.0037318493705242872,
0.025477223098278046,
0.030554670840501785,
-0.01880705915391445,
0.030010243877768517,
0.05106061324477196,
-0.037790294736623764,
0.024496356025338173,
-0.010621798224747181,
-0.06844567507505417,
-0.015123517252504826,
... |
<p>I have read that PP unit root is often used in economy. Is it sensible to do both tests (PP & ADF) or is PP test enough?</p> | g61044 | [
0.008459764532744884,
0.032461922615766525,
0.01879299432039261,
0.01617893949151039,
0.022122036665678024,
-0.054001759737730026,
0.0037215901538729668,
-0.019438445568084717,
0.023428743705153465,
0.01892302744090557,
0.04525061696767807,
0.031170014292001724,
-0.025055352598428726,
-0.0... |
<p>Does anyone know of examples of wrapping an existing piece of supervised learning software to output models in PMML format? Of particular interest are learners that just take in labeled vectors of numbers as training data and put out models that are pretty much just coefficient vectors (liblinear, SVMlight, BXRtrai... | g17467 | [
-0.029778920114040375,
-0.056863799691200256,
0.02108209952712059,
-0.06005265936255455,
-0.06854458153247833,
-0.03497600182890892,
-0.016936080530285835,
-0.004875718150287867,
-0.005560469813644886,
-0.05088133364915848,
0.023371515795588493,
-0.024058550596237183,
0.09576964378356934,
... |
<p>So I'm not sure if I 100% grasp confidence intervals. Say I have a huge data set of a bond prices from 1996 to present in MINUTES. Suppose I separate each data by day. If I were to use a Dickey Fuller Test (or any other t-test), on a particular day (thus a sample is drawn based on all points in one day) and the valu... | g17468 | [
0.03958272933959961,
-0.005372919607907534,
0.0012262726668268442,
-0.08204013109207153,
-0.052693549543619156,
-0.013015476986765862,
0.03938402235507965,
0.0031470132526010275,
-0.020306365564465523,
-0.027836430817842484,
0.0296917911618948,
-0.015672387555241585,
0.043404508382081985,
... |
<p>This question is about estimating cut-off scores on a multi-dimensional screening questionnaire to predict a binary endpoint, in the presence of correlated scales. </p>
<p>I was asked about the interest of controlling for associated subscores when devising cut-off scores on each dimension of a measurement scale (pe... | g61045 | [
-0.01637617126107216,
0.0005030986503697932,
0.022810108959674835,
-0.04950035735964775,
-0.011948974803090096,
0.02244700863957405,
0.04280755668878555,
0.005332609172910452,
0.01690460927784443,
0.000006835170552221825,
0.03095664270222187,
0.014446571469306946,
-0.016110211610794067,
0.... |
<p>I am analyzing student performance on a pre/post test designed to assess gains for a week long high school biology curriculum on natural selection.</p>
<p>After comparing pre/post performance using a variety of different metrics (test score, Rasch measure, chi-square per item) between the paired samples, I conducte... | g17470 | [
-0.0346781387925148,
-0.016950584948062897,
-0.009355215355753899,
0.0017598107224330306,
-0.030208099633455276,
-0.024304673075675964,
0.03203287348151207,
0.029293352738022804,
0.015053237788379192,
-0.023704834282398224,
-0.015448639169335365,
0.03484455868601799,
0.042176082730293274,
... |
<p>I have been trying to classify a set of data into one of four classes. The data has already been generated and I have set aside 10,000 for training and 2,000 for testing. I have also generated the labels for each of the data. Let's call the classes - 0,1,2 and 3.</p>
<p>Now when I observe the classification, I noti... | g61046 | [
-0.01784718595445156,
-0.01461421325802803,
-0.002186127472668886,
-0.047584112733602524,
0.00384479109197855,
-0.008783236145973206,
0.006617038510739803,
0.04002758860588074,
-0.0655578076839447,
-0.06822188943624496,
-0.00034189698635600507,
0.04052348434925079,
0.04721715673804283,
0.0... |
<p>I have 2 vectors of rural and urban populations of the same country. (years from 1975 to 2020) with only three values (1980, 1990 and 2001 years) in each. And I need to predict the missing data. My first approach was to interpolate the data in between the known years(using na.approx in R) and then use make an ARIMA ... | g61047 | [
0.030468959361314774,
-0.06732792407274246,
0.011717668734490871,
-0.03658776730298996,
-0.09033159911632538,
0.058945659548044205,
0.042301468551158905,
-0.004226847551763058,
-0.052353937178850174,
0.016292233020067215,
0.03781072422862053,
-0.005038829520344734,
0.0562216192483902,
0.00... |
<p>I've been assigned to solve the following problem as part of a serious, biological research project. I think I have a tentative solution, but I'm wondering whether the approach I've picked is the best. Your help/input would be appreciated. </p>
<p>We monitored the vital signs (V) of ten subjects as they travelled ... | g17471 | [
0.007117243483662605,
-0.024798069149255753,
-0.004836484789848328,
-0.0338037870824337,
0.0242373738437891,
-0.028341401368379593,
0.0563683845102787,
-0.03186551108956337,
-0.032576996833086014,
-0.013851018622517586,
0.040751539170742035,
0.05446912348270416,
0.04138966277241707,
-0.031... |
<p>I have data sets of the attendance of congresspeople, and of the weather in Washington, DC. I would like to examine whether and to what degree precipitation is correlated with the likelihood of individual congresspeople being present or absent.</p>
<p>For example, the 111th congress was in session 298 days of the 3... | g61048 | [
0.006638549733906984,
-0.0020790479611605406,
-0.0031753825023770332,
-0.0647335797548294,
-0.005390847567468882,
0.030202612280845642,
0.031413864344358444,
0.013383575715124607,
0.04264700785279274,
-0.027791472151875496,
0.003448080737143755,
0.0063173044472932816,
0.0433238260447979,
0... |
<p>I am using Matlab to forecast time series data using ARIMA algorithm. I am able to get forecasted values, but unable to get the fitted values.
This is what I mean. In R:</p>
<pre><code> model <- auto.arima(data)");
forecasted <- forecast.Arima(model, h=36)
forecasted$fitted
</code></pre>
<p><code>forecast... | g61049 | [
0.06092952936887741,
-0.06100969389081001,
-0.00009045787737704813,
-0.011223356239497662,
-0.00944550335407257,
0.007910861633718014,
-0.015804698690772057,
0.028059927746653557,
-0.056275445967912674,
0.00949392281472683,
0.003324323333799839,
0.05668575316667557,
0.06580696254968643,
-0... |
<p>Exploratory data analysis (EDA) often leads to explore other "tracks" that do not necessarily belong to the initial set of hypotheses. I face such a situation in the case of studies with a limited sample size and a lot of data gathered through different questionnaires (socio-demographics data, neuropsychological or ... | g61050 | [
0.02559174969792366,
0.07542351633310318,
0.000602422165684402,
-0.05065414682030678,
-0.025050152093172073,
-0.01551575306802988,
0.049659695476293564,
-0.03914177790284157,
0.015038088895380497,
-0.041521817445755005,
0.03914404287934303,
-0.039574235677719116,
0.05141974613070488,
0.024... |
<p>I am estimating a random intercept and a random slope model using the following R code. My dependent and independent variable are both continuous.</p>
<pre><code>randominterceptfixedslope<-lmer(y ~ x + (1|state),data=data,method="ML") # model with fixed slope but random intercept
randominterceptrandomslope<-l... | g61051 | [
0.037480395287275314,
-0.10529107600450516,
0.008106140419840813,
0.0017570750787854195,
0.03703102841973305,
-0.00005465357025968842,
0.05602633208036423,
-0.0003296934883110225,
-0.018917851150035858,
-0.007833018898963928,
-0.014835129491984844,
0.018523860722780228,
-0.0483439564704895,
... |
<p>I am reading an article which shows Hazard Ratios for continuous variables, but I'm not sure how to interpret the given values. </p>
<p>My current understanding of hazard ratios is that the number represents the relative likelihood of [event] given some condition. E.g: if the hazard ratio for death from lung cancer... | g17474 | [
0.04317295923829079,
-0.04647364094853401,
-0.011158451437950134,
-0.05635812133550644,
0.013433188199996948,
-0.019741538912057877,
0.026672178879380226,
0.029430074617266655,
-0.010596144944429398,
-0.015868213027715683,
0.03866836428642273,
-0.0023477869108319283,
0.014007961377501488,
... |
<p>Given a sample X of size n from a normal distribution $N(\mu,\sigma)$ one can estimate $\sigma$ by $\hat{\sigma}$ from X. Then we know that:</p>
<p>$p(\sigma|\hat{\sigma},n)\propto\hat{\sigma}\sqrt{\frac{n-1}{\chi^2(\nu=n-1)}}$</p>
<p>Now I am looking for the likelihood function: $p(\hat{\sigma}|\sigma,n)$.</p>
<... | g17475 | [
-0.008047102019190788,
-0.011238789185881615,
-0.007357308175414801,
-0.040959399193525314,
-0.017700213938951492,
-0.011295068077743053,
0.0050247060135006905,
-0.01010884065181017,
-0.021838653832674026,
0.013507493771612644,
-0.011722111143171787,
0.01995120756328106,
0.033182717859745026... |
<p>I know R is a very powerful tool for data mining and predictive model building. However, I'm finding it difficult to extract an equation from any sort of modeling that I do. For example, using something like:</p>
<pre><code>model <- lm(y~var1+var2+var3)
</code></pre>
<p>For data mining, I can use something li... | g61052 | [
0.029649514704942703,
-0.041303955018520355,
0.004834863357245922,
-0.03117271140217781,
0.0038663973100483418,
-0.06947789341211319,
0.010038869455456734,
0.01022788044065237,
-0.04470478370785713,
-0.056271616369485855,
0.02270873636007309,
0.014012112282216549,
0.04513924568891525,
-0.0... |
<p>I have an area divided into grids. I'm looking for a method to determine statistically, if the occurence of criminal incidents for two time periods is significant equal.</p>
<p>I have two datasets with equal periods and grid locations. The target values are only assigned to a specific time period. </p>
<p>TARGET =... | g17477 | [
0.04918784648180008,
-0.004244104493409395,
0.00009935624257195741,
-0.04036594182252884,
0.022050177678465843,
-0.018772581592202187,
0.02494175173342228,
0.028387626633048058,
-0.024755552411079407,
-0.011723981238901615,
0.04368456080555916,
0.04034455120563507,
0.07502033561468124,
0.0... |
<p>The expected model is:
$$
Y = X1*X2*X3
$$
Taking logs we should get a coefficient of $1$ on all three when we regress. That is:
$$
\ln (Y) = b + b1 \ln(X1) + b2 \ln(X2) + b3 \ln(X3), \\
\text{gives: }b1 = b2 = b3 = 1.
$$
What could be the reasons when we collect the data for all the variables and run the regressio... | g61053 | [
-0.01767697185277939,
-0.04350940138101578,
-0.008844824507832527,
0.01165841706097126,
0.0679720863699913,
-0.014402319677174091,
0.034432027488946915,
0.03172633796930313,
-0.027999818325042725,
-0.06854985654354095,
-0.030247963964939117,
0.050324685871601105,
0.0012529186205938458,
0.0... |
<p>I have one conceptual problem about a standard normal variate (SNV), $X$.</p>
<p>If $X \sim N(0, 1^2)$, then the probability density function (pdf) is given as </p>
<p>$f(x) = \frac{1}{\sqrt{2\pi}} \exp(-\frac{1}{2} x^2);\quad -\infty<x<\infty$</p>
<p><em><strong>My Problem :</em></strong></p>
<p>I unders... | g536 | [
0.034629907459020615,
-0.030418377369642258,
-0.007254139520227909,
-0.02310026064515114,
-0.020206889137625694,
0.009931819513440132,
0.0032671112567186356,
0.015066691674292088,
-0.020303349941968918,
-0.026682762429118156,
-0.0034506707452237606,
0.03405727818608284,
0.0028294124640524387... |
<p>Can the mean deviation about mean exceed the standard deviation for the Pareto distribution?</p>
<p>I just went through some books and found they are claiming that it cannot. </p>
<p>How can I prove that? What is the underlying logic that confirms this conclusion?</p> | g61054 | [
0.05675916373729706,
0.086520716547966,
0.002638255013152957,
0.01247648149728775,
-0.03744629770517349,
0.006626805290579796,
-0.0033736838959157467,
0.02436983957886696,
-0.016118621453642845,
-0.022578401491045952,
-0.02698211558163166,
-0.03656279295682907,
0.009602107107639313,
-0.023... |
<p>this is an exam practice question for my 1st year stats class and I just want to see if I have approached this problem correctly and to clarify my understanding.</p>
<p>Here is the complete question:</p>
<p>A professor is deciding whether to schedule an end of semester Stats exam in the morning (9am) or in the aft... | g17478 | [
0.0056933388113975525,
-0.04481590911746025,
-0.022464215755462646,
-0.03180522099137306,
0.021028226241469383,
0.023772794753313065,
0.09983408451080322,
-0.01968841440975666,
-0.011948940344154835,
-0.018112272024154663,
0.020003000274300575,
0.014714816585183144,
0.012753740884363651,
0... |
<p>I want to use caret to compare two different classification algorithms. For example SVM and Elastic net. </p>
<p>I want to put aside some samples for test set and then use the rest of the samples for training the model, which involves tuning some parameters (like alpha and lambda for elastic net) for which I use cr... | g28069 | [
-0.02953619696199894,
-0.031108083203434944,
0.02017202600836754,
-0.012968006543815136,
0.02005835808813572,
-0.0144713269546628,
0.010580696165561676,
0.026801355183124542,
-0.06279804557561874,
-0.0021538189612329006,
-0.03791090473532677,
0.04353095963597298,
0.035798314958810806,
0.00... |
<p>I have panel data and am interested in changes in total expenditures. I would like to consider an instrumental variable approach to deal with an endogenous regressor – the short run elasticity of income, lagged by 3 years. </p>
<p>There are two ways I can think to do this: </p>
<ol>
<li>I could calculate the elast... | g61055 | [
0.051098521798849106,
-0.021684125065803528,
-0.026517795398831367,
-0.03063397854566574,
-0.018632922321558,
-0.0022576164919883013,
0.03061903640627861,
-0.034113433212041855,
-0.02589447982609272,
0.033698517829179764,
0.02512051910161972,
0.035255271941423416,
-0.018465591594576836,
-0... |
<p>A set of final examination grades in a course is normally distributed with a mean of 73 and a standard deviation of 8. </p>
<ol>
<li>What is the probability of getting a grade below 91 on the exam? </li>
<li>What is the probability that a student scored between 65 and 89? </li>
<li>If the professor grades on a c... | g22078 | [
0.024019930511713028,
-0.011690687388181686,
0.011204070411622524,
0.00528290681540966,
0.003731130389496684,
0.08003517985343933,
-0.005449878517538309,
0.020846132189035416,
-0.04278253763914108,
-0.04013621062040329,
0.05754832178354263,
0.012753771618008614,
0.06988938897848129,
-0.064... |
<p>I need to use Lohr's (2d Ed) method of calculating a standard error for an estimate generated from a ratio estimator based on a stratified sample. In working out her example on page 145-146, I find that the fraction in her example is calculated opposite to how she shows it in her MSE equations on page 144. Specifica... | g61056 | [
0.04024752229452133,
-0.09328477829694748,
-0.0047805821523070335,
-0.05889479070901871,
-0.019386624917387962,
0.02889319509267807,
0.019541513174772263,
0.003078711684793234,
-0.037835367023944855,
0.04804954677820206,
0.00831548497080803,
0.01717790588736534,
0.053331442177295685,
0.031... |
<blockquote>
<p><strong>Possible Duplicate:</strong><br>
<a href="http://stats.stackexchange.com/questions/373/the-monty-hall-problem-where-does-our-intuition-fail-us">The Monty Hall Problem - where does our intuition fail us?</a> </p>
</blockquote>
<p>Marliyn vos Savant on <a href="http://marilynvossavant.com/... | g49611 | [
-0.015863992273807526,
0.04650849476456642,
0.0023810577113181353,
-0.01943899504840374,
0.0084379268810153,
-0.01613554172217846,
0.09105410426855087,
-0.013287183828651905,
-0.015778232365846634,
0.039563052356243134,
-0.04515286535024643,
-0.0044058021157979965,
-0.020511670038104057,
0... |
<p>I am new to statistics and have run into some trouble understanding computing confidence intervals and am seeking some help. I will outline the motivating example in my textbook and hopefully someone can offer some guidance. </p>
<p>Example </p>
<p>There is a population of mean values and your goal is to figure ou... | g49464 | [
0.028154049068689346,
0.012638560496270657,
-0.023520976305007935,
0.0217317882925272,
-0.021946357563138008,
0.02745811454951763,
0.0011128749465569854,
0.046781912446022034,
-0.062127139419317245,
-0.032552026212215424,
-0.027540860697627068,
0.029591519385576248,
0.035095423460006714,
-... |
<p>I am generating some Granger causality tests for various time-series. I have noticed something that appears odd. I have timeseries $A$ and $B$. Sample size is about 1500 elements in each.</p>
<p>$A$ and $B$ are highly correlated about 70%.</p>
<p>When I do a 1 ,2,or 3 lag Granger test I get p values like 0.0000000... | g47176 | [
0.08301258832216263,
-0.007711456622928381,
-0.021054359152913094,
-0.04405560344457626,
0.036207932978868484,
0.024009060114622116,
0.045052994042634964,
0.042828239500522614,
-0.03864927962422371,
-0.0076296450570225716,
0.048039719462394714,
0.051175110042095184,
-0.0229109525680542,
0.... |
<p>I have two groups of participants. Each group contains 30 children (15 girls and 15 boys). The first group has been sampled from a population of children being raised under some kind of constitutional care, while the second group represents children living in their families.</p>
<p>I want to measure their social sk... | g47177 | [
-0.004547148942947388,
-0.03661127761006355,
-0.02166270837187767,
-0.037647657096385956,
0.0075808558613061905,
-0.05374877527356148,
0.009579014033079147,
0.0012955141719430685,
-0.0006424610037356615,
-0.0026066310238093138,
0.017874734476208687,
-0.012888159602880478,
0.04538305476307869... |
<p>I have expression values (log2) for 200 genes in two conditions treated and untreated and for each condition I have 20 replicates.
The dataset looks like this:</p>
<pre><code>Gene UT1 UT2 T1 T2
DDR1 8.111795978 7.7606511867 7.9362235824 7.5974674936
RFC2 ... | g61057 | [
0.007895290851593018,
-0.0413707010447979,
-0.006968148984014988,
-0.03835337609052658,
0.0028694935608655214,
-0.008563588373363018,
0.0006248822901397943,
0.052920278161764145,
-0.07327892631292343,
0.0002507002791389823,
-0.041890889406204224,
0.06536388397216797,
0.037714164704084396,
... |
<p>I have problem in identifying a formative structural equation model using AMOS.Does anyone have any suggestion for dealing with the identification problem in formative measurement models?</p> | g43315 | [
0.018796978518366814,
-0.06092064455151558,
-0.004687647335231304,
-0.024503696709871292,
0.0032036497723311186,
-0.015586194582283497,
0.028435662388801575,
0.0006065733032301068,
0.04576363414525986,
-0.012260445393621922,
0.04236520454287529,
-0.007052878383547068,
0.07371753454208374,
... |
<p>Suppose we are estimating $\tau(\theta)=\theta e^{-\theta}$ from $X_1,...,X_n \sim \mathrm{G}(\theta,r)$ (G is the gamma distribution) then it is easily shown that $T=\sum_{i=1}^n \ln(X_i)$ is sufficient or $\exp(T)$ also. I'm wondering, is a continuous function of a sufficient statistic also sufficient and if $T$ i... | g27396 | [
-0.003269406734034419,
0.034370243549346924,
-0.027990534901618958,
-0.019977392628788948,
-0.01115734875202179,
-0.010203538462519646,
0.02980574406683445,
-0.018159085884690285,
-0.04196381941437721,
0.0375482402741909,
-0.033082183450460434,
0.019968757405877113,
0.0014587404439225793,
... |
<p>I have a scatter plot with Hgb A1C as the explanatory variable ('x' axis) and FPG ('y' axis)as the result variable. There is a positive linear relationship but it is weak. There is 1 outlier in the y direction. There is 1 outlier in the x direction. When each of these points is removed, r changes in opposite dir... | g61058 | [
0.05186355113983154,
-0.03329949453473091,
-0.004134044051170349,
-0.035336028784513474,
0.01886790432035923,
0.022999010980129242,
0.048410773277282715,
0.009424646385014057,
-0.04916730523109436,
-0.06023618206381798,
0.003619493218138814,
0.05399707704782486,
0.021822676062583923,
0.024... |
<p>Suppose $X_1$ and $X_2$ are bivariate normal and let $|X|_{(1)}$ and $|X|_{(2)}$
be the ordered version of their absolute value. I am interesting in finding the following probabilities or some bounds on it.
\begin{align*}
Pr(|X|_{(1)} < c_1, |X|_{(2)} < c_2)
\end{align*}
and
\begin{align*}
Pr(|X_1| < c_1,... | g61059 | [
-0.011202974244952202,
-0.050422877073287964,
-0.008493740111589432,
-0.02162391133606434,
0.0004133942420594394,
-0.043031901121139526,
0.029085997492074966,
-0.007051709108054638,
-0.08724500983953476,
0.03420223668217659,
0.04575321823358536,
0.06367940455675125,
-0.0010085039539262652,
... |
<p>I am pursuing my Ph.D. I am stuck with the last research objective. It talks about exploring the association of Brand Identity and Brand Image.</p>
<p>Sample Size for measuring Brand Image (Customer Respondents): 1200 (3 sectors with 4 brands each; Total Brands 12; Sample size of each brand 100)</p>
<p>Sample Size... | g9766 | [
-0.009903233498334885,
0.022234681993722916,
0.020661983639001846,
-0.007598268799483776,
-0.007504044100642204,
-0.0235715564340353,
-0.021267332136631012,
0.025287073105573654,
0.004824983887374401,
-0.0011946065351366997,
0.035821180790662766,
-0.018175775185227394,
0.07134000211954117,
... |
<p>I did this the obvious way, and my friend came back with a better idea. Can you guys adjudicate or improve on both?</p>
<p>My way:</p>
<blockquote>
<p>The Cincinnati Bengals and the Cleveland Browns both won on Sunday for the first time in 46 weeks (says ESPN). That seemed way too improbable...</p>
<p>46 is... | g43825 | [
-0.004652682226151228,
0.01050210278481245,
0.03144646808505058,
-0.014894559979438782,
-0.023818686604499817,
-0.02602275088429451,
0.009755321778357029,
0.0002827235439326614,
0.0023641118314117193,
0.02071760967373848,
0.04978702962398529,
0.049306537955999374,
0.05067840963602066,
-0.0... |
<p>I have the following data (just an small example here). I want to know effect of time and ecotype over height.
<code>subdata <-
id time ecotype height
1 17 a 73.692
1 22 a 213.010
1 25 a 343.700
1 28 a 663.030
109 32 a 1267.300
109 17 b 47.445
109 22 b 148.050
109 25 b 280.570
109... | g17487 | [
0.011999105103313923,
-0.04015541076660156,
-0.027061816304922104,
-0.0530124306678772,
0.032830871641635895,
-0.026061980053782463,
0.02758478745818138,
-0.016304904595017433,
-0.06771509349346161,
0.019179942086338997,
-0.034062013030052185,
0.06366715580224991,
0.0017048793379217386,
0.... |
<p>i need to know how to use the Australian Calculator to get my sample size. i was instructed to carry out my research using the Australian Calculator, but i don't know what it means.</p> | g61060 | [
0.021630264818668365,
0.02390180714428425,
0.002281991997733712,
-0.06270697712898254,
0.00815477967262268,
0.0335971862077713,
0.02158835344016552,
-0.010230161249637604,
0.015916243195533752,
-0.033110421150922775,
0.03421511501073837,
0.018720196560025215,
0.02884741872549057,
0.0059222... |
<p>In my experiment, I hypothesised that individuals in one treatment condition would give higher values on a likert scale than individuals in the other treatment condition. It was a one tailed hypothesis.</p>
<p>Histograms and Q plots show that my data is skewed in the direction I would imagine for the first treatmen... | g61061 | [
0.003041124902665615,
-0.03172335401177406,
-0.02004970796406269,
-0.05242817848920822,
0.0048030526377260685,
0.011659794487059116,
-0.013132119551301003,
0.022316230461001396,
-0.009086270816624165,
-0.014488426968455315,
0.05180538445711136,
0.044093888252973557,
0.011208402924239635,
-... |
<p>Is it possible to do a significance test based solely on precision/recall/F1 scores?</p>
<p>For example, if you come across 2 systems in a paper for which only P/R/F1 are reported (on the same dataset, etc.), can you then perform a statistical significance test? If yes, how is that done?</p> | g61062 | [
0.007918328046798706,
-0.00511076720431447,
0.0018031200161203742,
-0.006674787495285273,
0.029028097167611122,
-0.03869882971048355,
0.023398341611027718,
0.03021083027124405,
-0.00018797926895786077,
-0.05481397733092308,
0.020811567083001137,
-0.025562142953276634,
0.06107627972960472,
... |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.