question stringlengths 37 38.8k | group_id stringlengths 2 6 | sentence_embeddings listlengths 768 768 |
|---|---|---|
<p>In trying to implement Mixture Markov Model, (see question <a href="http://stats.stackexchange.com/questions/69563/can-log-likelihood-function-calculated-value-m-step-be-smaller-after-1-em-iter/69584#69584">here</a>), I have extreme cases ( e.g. 0's in the Transition Probability Matrix). I have approached this with ... | g61239 | [
-0.038854386657476425,
-0.0321941152215004,
0.001192895113490522,
-0.00893339142203331,
-0.04484834149479866,
-0.02975168079137802,
0.025074433535337448,
0.09340659528970718,
-0.018728181719779968,
-0.03609759360551834,
-0.010346808470785618,
0.001375144231133163,
0.07877971976995468,
0.05... |
<p>I fit a multiple <code>GLS</code> model with time series as a response and explanatory variables. I previously removed the seasonality and trends by using <code>
</code>. I found that the correlation structure of the residuals was AR(3), so I totally removed the autocorrelation from the residuals.The coefficient of ... | g61240 | [
0.01749836653470993,
-0.04427989572286606,
-0.0018100510351359844,
-0.05462957173585892,
0.00139099161606282,
0.0339977964758873,
0.03156336024403572,
0.03464708849787712,
-0.010478336364030838,
-0.004740735050290823,
-0.030605116859078407,
0.01987244375050068,
0.05180735141038895,
-0.0212... |
<p>I have a list of numbers that, when plotted on a graph, clearly demonstrate trends such as rising upwards, dropping, repeating etc.. When a human sees the graph, they can easily make out what's happening. What I'm trying to do is achieve the same thing numerically and have the system detect what trends are occurring... | g5363 | [
0.028669703751802444,
0.05307568609714508,
-0.01703694276511669,
-0.04082656279206276,
-0.011777287349104881,
-0.062248826026916504,
0.058825403451919556,
-0.0415651872754097,
-0.028619587421417236,
-0.0664864182472229,
0.006749153137207031,
0.059311721473932266,
0.06554874777793884,
0.097... |
<p>In the textbook I am reading they use positive definiteness (semi-positive definiteness) to compare two covariance matrices. The idea being that is A-B is pd then B is smaller than A. But I'm struggling to get the intuition of this relationship?</p>
<p>There is a similar thread here:</p>
<p><a href="http://math.st... | g17746 | [
0.03365061804652214,
-0.05461278185248375,
-0.011209181509912014,
-0.07048794627189636,
0.0409083291888237,
0.0012839492410421371,
0.018035994842648506,
0.0053650988265872,
-0.08145861327648163,
-0.01572117954492569,
0.05128045007586479,
0.033831436187028885,
0.01151969749480486,
0.0104492... |
<p>My problem is similar to this one but I am looking for a different solution: (so if it should be merged just let me know).</p>
<p><a href="http://stats.stackexchange.com/questions/21742/measuring-whats-lost-in-pca-dimensionality-reduction">Measuring what's 'lost' in PCA dimensionality reduction?</a></p>... | g61241 | [
0.023977449163794518,
-0.034297991544008255,
0.018851149827241898,
-0.10209089517593384,
0.024122832342982292,
-0.012410483323037624,
0.07824086397886276,
-0.020712343975901604,
-0.027567408978939056,
-0.03431672602891922,
0.012698875740170479,
-0.008537126705050468,
0.012587093748152256,
... |
<p>I am facing two problems while using <code>caret</code> package in R. I am reproducing an example below:</p>
<pre><code>library(mlbench)
library(caret)
set.seed(998)
data(Sonar) #Random data, just for illustration purpose
Sonar= Sonar[, 1:6] #Selected first 6 columsn only for showing an example. I am assuming V6... | g61242 | [
0.002421841025352478,
-0.06605371087789536,
0.00637804577127099,
-0.0451197475194931,
0.03927910327911377,
-0.01243897620588541,
0.0301612950861454,
-0.03566373512148857,
-0.04974569380283356,
-0.03911345452070236,
-0.03493693098425865,
0.04557771608233452,
0.022885838523507118,
-0.0032083... |
<p>I sometimes have to vectorise the Huber weights from a robust regression and use them in a lm.
Recently I've had to do something similar for a logistic model but I'm slightly worried because I don't get very similar results</p>
<pre><code>library(robustbase)
data(vaso)
ROB <- glmrob(Y ~Volume+Rate, family=binomi... | g61243 | [
0.012839294970035553,
-0.07654362916946411,
-0.002951002214103937,
0.0030495040118694305,
0.017819976434111595,
-0.014641650952398777,
0.018280016258358955,
-0.02649339847266674,
-0.07540038228034973,
-0.038543958216905594,
0.005189177114516497,
-0.008583689108490944,
0.05550295114517212,
... |
<p>Unfortunately, it's a long while since I did statistics and despite reading & research I'm not 'confident' as to how to calculate this correctly.</p>
<p>I would like to know the smallest sample size required in order to have a given confidence level that the sample mean would be with a given % of the population... | g61244 | [
0.02611309103667736,
0.028510816395282745,
-0.003639673348516226,
-0.016585934907197952,
-0.0456957183778286,
-0.02034972980618477,
-0.033503465354442596,
-0.019176771864295006,
-0.036872200667858124,
-0.04175160080194473,
0.019375352188944817,
0.00044175845687277615,
-0.008230403997004032,
... |
<p>Suppose you have a general regression model, which behaves like a black-box to you. All you have is a $\ \ \text{train}(X,Y) \ \ $ function, where you input your predictor matrix $X \in \mathbb R^{N\times M}$ and target vector $Y \in \mathbb R^N$, as well as a $\ \ \text{predict}(x) \ \ $ function which takes a row-... | g29993 | [
-0.05232549086213112,
-0.011721220798790455,
0.011503074318170547,
0.006515078246593475,
-0.031203100457787514,
-0.0952775850892067,
0.04655059054493904,
0.01761583611369133,
-0.015907078981399536,
0.020064758136868477,
0.031228359788656235,
0.02103443816304207,
0.0754660815000534,
-0.0234... |
<p>I am looking for a <em>non-parametric version of the multivariate repeated measures GLM procedure</em>. </p>
<p>I have ordered symptoms of a disease at 2 time points (0-3), and I want to show that they change differentially (in response to something that happens to the whole sample during the 2 time points). If my ... | g61245 | [
0.0072398134507238865,
-0.022173672914505005,
-0.02287742868065834,
-0.016811439767479897,
-0.01642422191798687,
-0.06727458536624908,
0.02767362631857395,
-0.04858090728521347,
-0.030750351026654243,
0.011062631383538246,
0.02964789979159832,
-0.008498234674334526,
-0.005521961487829685,
... |
<p>Let's say I have a fixed set of data containing one variable. I'm interested in whether the variable shows a difference between two conditions. Now I perform a test and determine a p-value somewhere above my desired alpha. Being disappointed, I iterate over multiple different alternatives of tests for the same hypot... | g61246 | [
0.03036305122077465,
-0.021408088505268097,
-0.01650686375796795,
-0.049919892102479935,
0.02257084846496582,
-0.045531850308179855,
0.024899745360016823,
0.007226454094052315,
-0.06668823957443237,
-0.04876727610826492,
0.04756955802440643,
0.050229355692863464,
-0.002321060514077544,
0.0... |
<p>Just a foreword, I'm not a mathematician or otherwise statistically skilled. I know my way around calculating standard deviations, but it's all self taught. I'm a programmer with limited stats knowledge. </p>
<hr>
<p>Now, Assume that you run a "Widget Rental" website, and on your application you allow owners of "W... | g61247 | [
-0.015458117239177227,
0.04842042177915573,
-0.014600910246372223,
-0.026841657236218452,
-0.044930599629879,
-0.05893561989068985,
0.030846746638417244,
0.023485174402594566,
-0.008926080539822578,
0.009846222586929798,
-0.012021280825138092,
0.05535870045423508,
0.07305626571178436,
-0.0... |
<p>I did an experiment looking at damage to marine organisms as a result of fishing. I sampled in three vessels A, B and C. In each vessel I sampled the catch before on-deck handling (Pre) by fishermen and after (Post) on-deck handling by fishermen and counted the number of damaged individuals within the sample. My dat... | g17750 | [
0.02677074633538723,
-0.05826340243220329,
-0.013827381655573845,
-0.06955480575561523,
0.023145001381635666,
0.007135698106139898,
0.0292334146797657,
-0.005673411767929792,
-0.044145289808511734,
-0.014656413346529007,
0.04135839268565178,
0.05830853804945946,
0.036376021802425385,
-0.01... |
<p>I have an experiment in which I have four fenced large plots. I subdived every fenced plot into three smaller fences to have three grazing levels. Within every grazing level I planted 20 saplings either under a shrub or standing alone.
I want to build a statistical model where microsite (under shrub, standing alone... | g61248 | [
0.010718418285250664,
-0.05472569540143013,
-0.029070159420371056,
-0.011155180633068085,
-0.006599915213882923,
-0.02434823103249073,
0.06484666466712952,
-0.010197163559496403,
-0.007164771668612957,
-0.02142747864127159,
-0.03745679184794426,
0.02792627550661564,
0.040776513516902924,
-... |
<p>The correlationmatrix shows that some of my predictors are correlating (Pearson, 0,288<br>
0,492 and 0,360) I think it is useful to have additional information to decide whether this is acceptable or not. </p>
<p>Can I simply run a linear regression for all my independents and use R2 to calculate VIF? (VIF = 1/(1-R... | g61249 | [
0.017871279269456863,
-0.07922970503568649,
0.007939565926790237,
-0.007132196333259344,
0.004093156661838293,
-0.012209698557853699,
0.006687899585813284,
0.01729540154337883,
-0.03817771375179291,
-0.04016393795609474,
0.01607431471347809,
0.030574001371860504,
-0.032528918236494064,
-0.... |
<p>The answer to <a href="http://stats.stackexchange.com/questions/25290/what-is-the-probability-px-y-given-x-bea1-b1-and-y-bea2-b2-and-x">What is the probability P(X > Y) given X ~ Be(a1, b1), and Y ~ Be(a2, b2), and X and Y are independent?</a> provides an analytical solution for this, but is there a less computat... | g17756 | [
0.005008242558687925,
0.02560381218791008,
-0.0019524783128872514,
0.013068269938230515,
-0.02868303842842579,
-0.027611056342720985,
0.044989243149757385,
0.007717386819422245,
-0.015950072556734085,
0.024058733135461807,
-0.016139792278409004,
0.06968654692173004,
-0.0046692718751728535,
... |
<p>Apparently, for K-means clustering, the decision boundary for whether a data point lies in cluster $A$ or cluster $A'$ is linear.</p>
<p>I don't quite understand this statement. Why is it linear? Every iteration of K-means clustering, I reassign data points to clusters to minimize square error. Then, I reassign the... | g61250 | [
0.03809953108429909,
-0.04119200259447098,
-0.014261199161410332,
0.040371306240558624,
0.07396990060806274,
-0.047524336725473404,
-0.006845938973128796,
0.04911881312727928,
-0.03567185252904892,
-0.026316199451684952,
-0.027112707495689392,
0.060984209179878235,
0.07727383822202682,
0.0... |
<p>I have been given a data set that contains the number of awards earned by students at one high school where predictors of the number of awards earned include the type of program in which the student was enrolled and the score on their final exam in maths. </p>
<p>I was wondering if anyone could tell me why a linear... | g61251 | [
0.019551439210772514,
0.007512891665101051,
0.009109625592827797,
-0.043815430253744125,
-0.01263338141143322,
-0.008659588173031807,
-0.013240691274404526,
0.03871145471930504,
-0.00499858008697629,
-0.04695210978388786,
0.0025140929501503706,
0.01644686423242092,
0.021831713616847992,
-0... |
<p>This is an obfuscated version of a real problem:</p>
<p>Each day I speak with some number of (distinct) girls.
I compute the Jaccard similarity index between two consecutive days:</p>
<pre><code>J(t)=J(t,t-1)=Intersection(girls(t),girls(t-1))/Union(girls(t),girls(t-1))
</code></pre>
<p>I would like to compare J(t... | g61252 | [
-0.01561183575540781,
0.01943139359354973,
-0.006141966208815575,
-0.08747082203626633,
-0.029715493321418762,
-0.0032651692163199186,
0.0213700570166111,
-0.0015643080696463585,
-0.007512891199439764,
0.02709433250129223,
-0.019684655591845512,
0.008764517493546009,
0.04894665256142616,
0... |
<p>I am currently working to build a model using a multiple linear regression. After fiddling around with my model, I am unsure how to best determine which variables to keep and which to remove.</p>
<p>My model started with 10 predictors for the DV. When using all 10 predictors, four were considered significant. If I ... | g17758 | [
0.0023049237206578255,
-0.04768909513950348,
0.012457050383090973,
0.014608359895646572,
0.02371474914252758,
-0.04524041712284088,
0.010015003383159637,
0.07905174046754837,
-0.014749477617442608,
-0.005726008675992489,
-0.02844952419400215,
-0.03160930052399635,
0.009237457998096943,
0.0... |
<p>I have a system which visits two locations and collects signals every 10 seconds. It is well known that A causes B to occur but not all the time. So, I am trying to find a conditional probability distribution of B given A.</p>
<p>The data looks like following:</p>
<pre><code>A B
----------
1 0
1 1... | g61253 | [
0.06423576921224594,
0.016078317537903786,
0.006719708442687988,
-0.027352361008524895,
0.029112927615642548,
-0.02264350838959217,
0.07170072942972183,
0.040868327021598816,
-0.04699496552348137,
-0.062066443264484406,
-0.00806790217757225,
-0.005572561640292406,
0.03626854345202446,
0.00... |
<p>I have some time series data of measurements taken at random intervals with dimensions >> measurements, with intervals anywhere between 15 seconds and a few minutes. Ideally I would like to have a continuous time estimate to give me the state of the system at any time between the beginning and end of measurements wi... | g61254 | [
0.028581563383340836,
-0.015851572155952454,
-0.007542730774730444,
0.0058815679512917995,
-0.08422903716564178,
-0.028970791026949883,
0.03381321579217911,
-0.021527251228690147,
-0.0353114940226078,
0.0215906985104084,
0.007844782434403896,
0.013986129313707352,
0.034611038863658905,
-0.... |
<p>I was given an exercise to do that sounded something like this:</p>
<p>The Arizona football team scored $45$ goals in $19$ games in the 2007/08 season. If $y_i$ denotes the number of goals scored in the $i$-th game, consider the following model:</p>
<p>$Y_1,\dots,Y_n \sim \operatorname{Poisson}(\lambda)$ independe... | g61255 | [
-0.018474845215678215,
0.08364326506853104,
-0.04454563185572624,
-0.014108894392848015,
0.00429557403549552,
0.00761302188038826,
-0.006393790245056152,
-0.028636645525693893,
-0.026120280846953392,
-0.034615106880664825,
-0.03503013402223587,
-0.0001742870663292706,
0.04481397941708565,
... |
<p>I have a very large graph and a function of its vertices, and want to estimate mean value of this function.
It's not possible to sample vertices uniformly in this problem, so a reasonable choice for estimation would be simple random walk.
The problem is that for any vertex I can only pick a random neighbour of it; f... | g37488 | [
-0.023915234953165054,
0.011119349859654903,
0.001756872283294797,
-0.006590835750102997,
-0.04943377152085304,
-0.043114691972732544,
-0.0019273104844614863,
-0.0034955530427396297,
-0.0012413610238581896,
-0.006904274225234985,
-0.0009675936889834702,
0.016642345115542412,
0.02069432102143... |
<p>I am new to Bayesian statistics, and thus have problems to come up with a solution for the following problem:</p>
<p>Using Approximate Bayesian Computation (ABC), I generate a posterior distribution from one set of observed summary statistics, and a set of about a million simulated summary statistics. The prior dis... | g47494 | [
0.013349912129342556,
-0.0012031736550852656,
-0.0003364703734405339,
-0.054592303931713104,
-0.024001844227313995,
0.022045398131012917,
-0.0369756780564785,
-0.014896341599524021,
-0.04174165427684784,
0.02031232975423336,
0.0004491741128731519,
-0.00754663348197937,
0.020952953025698662,
... |
<p>I usually hear about "ordinary least squares". Is that the most widely used algorithm used for linear regression? Are there reasons to use a different one?</p> | g61256 | [
0.07844822108745575,
-0.03414043411612511,
0.010237329639494419,
-0.04257385805249214,
-0.04299457371234894,
-0.0938742458820343,
-0.015046913176774979,
-0.0005548113258555532,
0.0194621030241251,
-0.0013640997931361198,
0.0454084649682045,
0.006136144977062941,
0.05632619187235832,
0.0052... |
<p>I have clustered over 4000 textual files, and now I want to check and evaluate clusters. I want to use <a href="http://en.wikipedia.org/wiki/F1_score" rel="nofollow">F-measure</a> (a mix of recall and precision). </p>
<p>The formal definition of F1_score is:<br>
$$
\text{F-measure} = 2 * \frac{\text{precision} * \t... | g47496 | [
-0.03696747124195099,
-0.0012317330110818148,
-0.018371425569057465,
-0.06430021673440933,
0.03877675160765648,
-0.10355987399816513,
-0.01879711076617241,
0.08065399527549744,
-0.07377498596906662,
-0.0370558425784111,
-0.03060832992196083,
-0.01923755370080471,
0.05331426486372948,
-0.01... |
<p>I was wondering if there is a relationship between $R^2$ and a F-Test.</p>
<p>Usually $$R^2=\frac {\sum (\hat Y_t - \bar Y)^2 / T-1} { Y_t - \bar Y)^2 / T-1}$$ and it measures the strength of the linear relationship in the regression.</p>
<p>An F-Test just proves a hyptheses.</p>
<p>Is there a relationship betwee... | g17767 | [
0.0028517059981822968,
-0.00391912879422307,
-0.014645417220890522,
-0.0017354352166876197,
-0.004417485557496548,
-0.054462749511003494,
0.015382788144052029,
-0.010669151321053505,
-0.02901185303926468,
-0.04508606344461441,
-0.027879169210791588,
0.0015873810043558478,
0.00483173877000808... |
<p>How would you describe <a href="http://en.wikipedia.org/wiki/Cross-validation_%28statistics%29"><strong>cross-validation</strong></a> to someone without a data analysis background?</p> | g61257 | [
0.031323544681072235,
0.004258102737367153,
-0.020065808668732643,
-0.024974605068564415,
0.022448936477303505,
0.05156530439853668,
0.02018663100898266,
0.018324457108974457,
0.016383977606892586,
-0.02337643690407276,
0.0037246609572321177,
0.0048132482916116714,
0.034747783094644547,
-0... |
<p>How do i test/verify if i can analyze my panel like dataset by simply pooling the individual series?</p>
<p>I have a dataset structured as a panel. Now I am wondering if i can simply
pool the individual series and estimate it via OLS or if I have to use another estimation technique.</p>
<p>(Any R hints and referen... | g17768 | [
0.005321899428963661,
-0.005406260024756193,
0.00863124430179596,
-0.07749360799789429,
-0.001531552174128592,
-0.0335853286087513,
0.009829573333263397,
0.01088939979672432,
-0.043597422540187836,
-0.05146852880716324,
-0.04021123796701431,
0.06365320086479187,
0.017936309799551964,
0.036... |
<p>Apparently any new video on YouTube seems to freeze at 301 views for a period of time before the actual views start reflecting. <a href="http://www.businessinsider.in/This-Is-Why-All-New-YouTube-Videos-Get-Exactly-301-Views/articleshow/21880671.cms" rel="nofollow">The reason</a> seems to be that youtube during this ... | g61258 | [
0.005617736838757992,
0.014284936711192131,
-0.005847865249961615,
0.0037655620835721493,
0.0418543815612793,
0.026075949892401695,
0.07568234205245972,
-0.005207541398704052,
-0.014045554213225842,
-0.033318087458610535,
-0.036021117120981216,
0.04819318279623985,
0.05541187897324562,
0.0... |
<p>A colleague in my office said to me today "Tree models aren't good because they get caught by extreme observations".</p>
<p>A search here resulted in <a href="http://stats.stackexchange.com/questions/1292/what-is-the-weak-side-of-decision-trees">this thread</a> that basically supports the claim.</p>
<p>Which leads... | g61259 | [
-0.010198061354458332,
0.03645095229148865,
-0.010874918662011623,
-0.012063246220350266,
0.056610848754644394,
-0.026285065338015556,
-0.018401198089122772,
-0.033822350203990936,
-0.0400988906621933,
0.019272590056061745,
0.013744724914431572,
0.00021116944844834507,
0.10048940032720566,
... |
<p>Is there a a good python library for training boosted decision trees ?</p> | g37666 | [
-0.006107813213020563,
0.02691526710987091,
0.02272735722362995,
-0.05253620445728302,
0.016690129414200783,
-0.03608303889632225,
-0.0777304470539093,
0.033098552376031876,
0.0035570187028497458,
-0.0243935938924551,
8.310030352731701e-8,
0.03069995902478695,
0.06759103387594223,
0.042226... |
<p>I am trying to calculate the Newey-West standard errors but I get stuck with the E value of (X'X)^-1. What is E actually doing? If it is the mean how would you compute it? Please give a short example with values so that I would be able to replicate it. Values could be X'={{1,1,1},{2,3,4}} where X is a 2 x 3 matrix w... | g17773 | [
-0.026477327570319176,
-0.004525789525359869,
-0.022748133167624474,
0.0018231365829706192,
0.0031806188635528088,
-0.01561796572059393,
0.010321315377950668,
-0.021521754562854767,
-0.02707710489630699,
0.022546866908669472,
-0.013098598457872868,
0.03136075288057327,
0.06076556444168091,
... |
<p><a href="http://www.cs.cmu.edu/~awm/">Andrew More</a> <a href="http://www.autonlab.org/tutorials/infogain11.pdf">defines</a> information gain as:</p>
<p>$IG(Y|X) = H(Y) - H(Y|X)$</p>
<p>where $H(Y|X)$ is the <a href="http://en.wikipedia.org/wiki/Conditional_entropy">conditional entropy</a>. However, Wikipedia call... | g61260 | [
0.046893410384655,
-0.01259156409651041,
-0.0352049395442009,
-0.04158441722393036,
0.007996892556548119,
0.012705250643193722,
0.02480860985815525,
0.007635287009179592,
-0.036671172827482224,
-0.0018919330323114991,
-0.03636039048433304,
-0.017213433980941772,
0.030384566634893417,
-0.00... |
<p>I'm trying to apply one of the Framingham cardiovascular event risk scores to a new dataset in order to get absolute risk. D'Agostino 2013 "Cardiovascular Disease Risk Assessment: Insights from Framingham" says the procedure is</p>
<ol>
<li><p>Set means $M_1,\dots,M_p$ to be the mean of each of your new study risk ... | g35996 | [
0.006152484565973282,
-0.06937847286462784,
0.003992787096649408,
0.007280583493411541,
-0.003392128273844719,
-0.02809397503733635,
-0.006703031715005636,
0.04868410527706146,
-0.0660700723528862,
-0.011410582810640335,
0.03625795990228653,
0.033162545412778854,
0.06920503079891205,
-0.02... |
<p>I am using the leave one out cross-validation technique to evaluate my model. If the prediction on the test sample is right the output is 1 otherwise 0. So I have a array of N samples with 0's and 1's at the end of it. I then average these values to get the average prediction accuracy and calculate the Standard devi... | g61261 | [
-0.023142315447330475,
-0.019227160140872,
0.023241214454174042,
-0.009313414804637432,
-0.002534230938181281,
0.021475674584507942,
0.0724702849984169,
0.05645965784788132,
0.007988293655216694,
0.01937815360724926,
0.022091064602136612,
-0.04635531082749367,
-0.013243969529867172,
0.0532... |
<p>I'm trying to build a monitoring system that will automatically raise a warning when a dramatic change happens to some of the observed parameters. </p>
<p>My problem looks like this: We send out e-mails to a large number of recipients. For each pile of emails, we have a few parameters such as the number of e-mails ... | g17778 | [
0.025898627936840057,
0.02735923044383526,
-0.007606216240674257,
-0.045674972236156464,
-0.003877714043483138,
-0.04702986031770706,
0.04101340472698212,
0.0023326335940510035,
-0.018570538610219955,
0.006176788825541735,
-0.010378524661064148,
0.03140538930892944,
0.09779967367649078,
0.... |
<p>I'm reviewing a paper. In it the authors use a genetic distance metric to created a distance matrix between subjects, then they run classic MDS on this distance matrix. Throughout the MS they call this a principal components analysis (PCA). I was trained to call this principal coordinates (PCO) or classic multidim... | g17779 | [
0.026343263685703278,
-0.020840046927332878,
-0.005715875420719385,
-0.0663372203707695,
-0.05612917244434357,
0.003241998143494129,
0.04148372262716293,
-0.001522347331047058,
-0.061005961149930954,
-0.0036578085273504257,
0.03842364624142647,
-0.00197255564853549,
0.06766794621944427,
-0... |
<p>I am not sure what the right keywords would be for this but I would like to know if it is possible to apply functions to random variables. I think it may make sense in terms of expected value but I would appreciate any information on a more formal or rigorous approach to this concept.</p>
<p>For example if there wa... | g61262 | [
-0.04185708239674568,
-0.0031557190231978893,
0.0053830621764063835,
-0.05616087093949318,
-0.028983308002352715,
-0.03792766109108925,
0.014102918095886707,
0.012818457558751106,
-0.038521118462085724,
-0.0358102023601532,
-0.03125864267349243,
0.019950198009610176,
0.040852587670087814,
... |
<p>I am working with multivariate numerical data with a lot of missing values (so dropping all entries or columns with missing data is not an option). </p>
<p>Is there a Python package for data imputation?</p>
<p>I am interested mainly in methods based on linear regression (plus estimation of variance of the predicte... | g61263 | [
0.0634094849228859,
-0.06908325850963593,
-0.0099079180508852,
-0.03939542919397354,
-0.0373886413872242,
-0.006226183380931616,
-0.003488164860755205,
-0.019213948398828506,
-0.029803205281496048,
-0.020455557852983475,
-0.012958107516169548,
0.0011741651687771082,
-0.0036570753436535597,
... |
<p>Let's say we want to randomize 400 caregivers to a parenting intervention or a wait-list control group. But we also want to look at a program variation for a sub-sample of caregivers of children with identified conduct problems (e.g., a more intense version of the program adds home visits to the standard program com... | g61264 | [
-0.047840774059295654,
0.017796194180846214,
-0.011351984925568104,
-0.0028768612537533045,
0.024993833154439926,
-0.05452592670917511,
0.05071045085787773,
0.030753374099731445,
0.03530058637261391,
-0.020536350086331367,
0.01274830475449562,
0.015612528659403324,
0.02791619300842285,
0.0... |
<p>I have been very interested lately in learning Bayesian Statistics, but I have only a little bit of background in the frequentist statistics, only one term at University. </p>
<p>Some of the books that I have seen are extremely mathematically oriented like:</p>
<ul>
<li>Bayesian Theory, José Bernardo. Probability... | g49573 | [
0.06375139206647873,
-0.012409205548465252,
0.006580730434507132,
-0.056156180799007416,
-0.033869899809360504,
0.014065545983612537,
-0.026766186580061913,
0.023944517597556114,
0.006370324641466141,
0.008427118882536888,
0.023606574162840843,
0.015268624760210514,
0.07934106886386871,
0.... |
<p>My dependent variable shown below doesn't fit any stock distribution that I know of. Linear regression produces somewhat non-normal, right-skewed residuals that relate to predicted Y in an odd way (2nd plot). Any suggestions for transformations or other ways to obtain most valid results and best predictive accurac... | g49415 | [
-0.000720253330655396,
-0.060789287090301514,
-0.021154919639229774,
-0.022687386721372604,
-0.07189406454563141,
-0.03164274990558624,
-0.002058125799521804,
-0.006410896312445402,
-0.0025696679949760437,
-0.012529892846941948,
0.037658777087926865,
0.024532387033104897,
0.04001973569393158... |
<p>I have a unusual sampling problem.</p>
<p>I have a continuously growing file with millions of words in it. Each word can have 1 to 8 characters in them. A word can have duplicate characters in them. The task is to eliminate the repeated characters within each word, but I want to do this only if the total number of ... | g61265 | [
0.030359141528606415,
0.0036152033135294914,
0.019144726917147636,
-0.07880109548568726,
-0.08087820559740067,
-0.03208310902118683,
-0.01387028582394123,
0.06047602370381355,
-0.027742773294448853,
0.04741929471492767,
-0.04526849463582039,
0.006235607899725437,
-0.061485424637794495,
0.0... |
<p>Assume I have a number of subjects dividing into three profiles: 1, 2 and 3. For each subject I have recorded two attributes, age and height. First, I want to determine if there is a significant age-difference between the profiles. This can be done using a simple ANOVA test.</p>
<p>Now I want to determine if there ... | g61266 | [
0.03247097507119179,
0.0032818627078086138,
0.0065390546806156635,
-0.030558334663510323,
-0.006418224424123764,
0.022427165880799294,
0.0606607049703598,
-0.005549455527216196,
-0.042498886585235596,
0.029196668416261673,
-0.02676377445459366,
0.02572125568985939,
0.04883148521184921,
-0.... |
<p>I have a problem with a simple Naive Bayes calculation. Given that I have an inbox, with the following characteristics:</p>
<ul>
<li>The mailbox contains 100 emails</li>
<li>50 emails contain the word “money”.</li>
<li>30 emails contain the word “viagra”.</li>
<li>The user manually flagged 30 emails as spam, of whi... | g61267 | [
0.02084076963365078,
0.05995570123195648,
-0.0025005184579640627,
-0.010361368767917156,
-0.0033466171007603407,
-0.02430005557835102,
-0.001053097192198038,
0.06126520410180092,
-0.0053800861351192,
0.009073803201317787,
-0.04836289584636688,
0.014065593481063843,
-0.0018178760074079037,
... |
<p>I'm currently writing my thesis and derived some closed form solutions. However, these solutions need to get estimated to use in practice. I thus should know the multivariate distributions of some stochasts. The found formula is as follows: </p>
<p>$\frac{ \sum_{i=1}^n \sum_{j\neq i} var(\bar{c}_{i,j}) - cov( c_{i,... | g61268 | [
0.018218660727143288,
-0.019093802198767662,
-0.024971207603812218,
-0.04179251194000244,
-0.04113663360476494,
-0.01617518439888954,
0.012264915741980076,
-0.05304773896932602,
0.00018112796533387154,
0.023678196594119072,
-0.020057303830981255,
0.05226793885231018,
0.0004175262001808733,
... |
<p>Using Firth's penalized likelihood method in logistic regression, why can you get a p-value of <.05 when the confidence interval for the estimate includes 1? </p>
<p>code: </p>
<pre><code>PROC LOGISTIC DATA=model PLOTS(ONLY)=effectplot OUTMODEL=fq2;
MODEL outcome (EVENT='1')= variable1 variable2 /FIRTH ... | g17786 | [
0.042927008122205734,
-0.04576314240694046,
-0.021998828276991844,
-0.012627892196178436,
0.03435184434056282,
-0.0003802689316216856,
-0.02436075545847416,
0.005072541534900665,
-0.05034906789660454,
-0.04986726492643356,
0.008210060186684132,
0.023735035210847855,
0.05772518739104271,
0.... |
<p>Let's say I have the following scenario:</p>
<blockquote>
<p>A mouse is put into a maze that's constructed as below:</p>
<p><img src="http://i.stack.imgur.com/iv0jP.jpg" alt="enter image description here"></p>
<p>There are 9 rooms with connections between the rooms as indicated with
a "gap" in the "wa... | g61269 | [
-0.0029880176298320293,
0.07818227261304855,
-0.005455970764160156,
0.006172010209411383,
-0.0381295271217823,
-0.07153180241584778,
0.08502986282110214,
0.028994256630539894,
-0.013583452440798283,
0.05420995131134987,
-0.045462895184755325,
0.03466881439089775,
0.004073788411915302,
0.03... |
<p>I've got some problems with selecting right model/method in my analysis.</p>
<p>Two groups of animals (differ by "Treatment") were measured from 1-st to 42-nd day, one common value for each group was measured by each day (food consumption per day).
I need to compare this groups and I want to use ANCOVA with "Treatm... | g17787 | [
-0.03561287000775337,
-0.07447628676891327,
-0.010975158773362637,
-0.05735379084944725,
-0.021868377923965454,
-0.014883936382830143,
0.06229237839579582,
-0.01982739195227623,
-0.026075128465890884,
0.0370248518884182,
0.05795768275856972,
-0.004785215947777033,
0.012515159323811531,
0.0... |
<p>I've been doing some reading about learning to rank - specifically lambdaMART - and one thing I am confused about is the role of features. When training a model, should one only use query-dependent features (as in features derived from both the query and document)?
Could you train on a set of query-independent feat... | g17788 | [
-0.023101268336176872,
0.005664966069161892,
0.00651721702888608,
-0.02698238007724285,
0.01456260122358799,
-0.022142887115478516,
-0.03097778744995594,
0.04491759091615677,
-0.07204639911651611,
-0.05945369973778725,
0.032332904636859894,
0.025102930143475533,
0.09693721681833267,
0.0113... |
<p>Lets say we have 1 to 6 repeted measures over time for some (many) subjects, and the outcome is values between 0 and 23 (so we assume normal distribution). For a normal distribution the fixed effects has interpretation of population average in a mixed model. So we can either use a mixed model or a marginal model (ge... | g61270 | [
0.0009446239564567804,
-0.02426738105714321,
0.01739695854485035,
-0.0244175773113966,
0.0008388108108192682,
0.045499999076128006,
0.039033833891153336,
0.012336723506450653,
0.03249002993106842,
-0.04348070174455643,
0.061201777309179306,
0.003218273166567087,
-0.014141607098281384,
-0.0... |
<p>How can I interpret the coefficients of the crossproduct of each of the following codes? What do they mean? How can I deduce that they correspond to our expectation?</p>
<pre><code>fit.model=lm(formula = CO ~ ., data = cigarettes)
Call:
lm(formula = CO ~ ., data = cigarettes)
Coefficients:
(Intercept) Tar... | g61271 | [
-0.000413750036386773,
-0.0732317715883255,
-0.012056383304297924,
-0.08794819563627243,
0.07266701757907867,
-0.05441361665725708,
0.07353311777114868,
-0.012334030121564865,
-0.03759387880563736,
0.026505442336201668,
-0.04163140431046486,
-0.014494068920612335,
0.0660666897892952,
-0.03... |
<p>I have a sample and I've classified each member into 3 groups A,B,C. </p>
<p>To get uncertainties on the percentages of these groups, I've been told I should use the <a href="http://en.wikipedia.org/wiki/Binomial_proportion_confidence_interval#Wilson_score_interval" rel="nofollow">wilson score interval</a>. As some... | g61272 | [
0.007427801378071308,
-0.01771809533238411,
-0.018892472609877586,
-0.0053135696798563,
0.024245643988251686,
-0.003133289283141494,
0.0010429385583847761,
0.024422502145171165,
-0.04279685765504837,
-0.039381932467222214,
0.014788644388318062,
0.015268081799149513,
-0.023643627762794495,
... |
<p>I have time-series count data $N_{i,j}$ (population sizes in site $i$ and year $j$) and I want to correlate year-to-year changes with the environmental conditions $x_{i,j}$. For this, I want to fit this model:</p>
<p>$$\begin{eqnarray}
\mbox{log} ( \mu_{i,j+1} ) &=& \mbox{log} ( \mu_{i,j} ) + \alpha + \beta... | g61273 | [
0.03708656504750252,
-0.05068373680114746,
-0.0017163190059363842,
-0.040830232203006744,
-0.0005829929723404348,
0.00471641356125474,
0.014354582875967026,
-0.0024072190281003714,
-0.029518621042370796,
0.043212614953517914,
0.006589269731193781,
0.0058645447716116905,
0.02263391762971878,
... |
<p>I’ve got two main groups, which I am comparing, a) rats and b) rabbits. Each group consists of two subgroups – breed 1 and breed 2.</p>
<p>Using linear regression, I would need to find out, does a model taking into account the subgroups account for more variance than a model with only the main groups.</p>
<p>So I ... | g61274 | [
-0.00971971545368433,
-0.05362968146800995,
-0.011728867888450623,
0.01802693121135235,
0.052702851593494415,
-0.035570211708545685,
-0.022592516615986824,
0.021784909069538116,
-0.01984819769859314,
0.0019329083152115345,
0.018709246069192886,
0.053198449313640594,
0.007303854450583458,
0... |
<p>I'm trying to find the best distribution that fit my data (sample size of 7210).<br>
Some of the distributions that have a low Anderson–Darling value look very similar to my data. But all the p-values show insignificance. Is that because of the sample's size?</p>
<p>Anyway if I do a plot for Loglogistic, for exampl... | g49510 | [
0.05817025154829025,
-0.015932675451040268,
0.0004914237651973963,
-0.0762302428483963,
-0.04674912616610527,
-0.016276462003588676,
-0.013092153705656528,
-0.009941721335053444,
-0.034825172275304794,
-0.0559392087161541,
-0.0075530088506639,
-0.009951997548341751,
0.05240418389439583,
-0... |
<p>I am looking at the statistics of this paper: <a href="http://emotional.intelligence.uma.es/documentos/6-Extremera2011Emotional.pdf" rel="nofollow">http://emotional.intelligence.uma.es/documentos/6-Extremera2011Emotional.pdf</a>
I am wondering how you can use the z-test to compare the two correlation coefficients?
... | g61275 | [
0.004610266070812941,
-0.025378694757819176,
-0.006032401230186224,
-0.013466915115714073,
0.018974274396896362,
-0.046937599778175354,
0.05369161441922188,
0.011242530308663845,
-0.008900613524019718,
0.002280149608850479,
0.029667973518371582,
0.015486596152186394,
0.04100548475980759,
0... |
<p>Say there is a hypothesis that A causes B (A -> B), and some likelihood that the hypothesis is correct (AB1%).</p>
<p>Now, an experiment is run that claims to find a correlation between A and B.</p>
<p>What I would like to know is whether my new probability (AB2%) is greater than, or less than, my previous probabi... | g61276 | [
0.06986378878355026,
-0.036648642271757126,
0.0017593749798834324,
0.01744459941983223,
0.06580566614866257,
-0.016170773655176163,
0.006745908409357071,
0.04911144822835922,
0.011956796981394291,
-0.029466433450579643,
0.02586938813328743,
-0.02263738587498665,
-0.005358789581805468,
0.02... |
<p>I have distributional data which I represent as a density. The data represents frequencies of user activities on a computer screen (e.g. amount of clicks on the y or x-axis of that screen but also other activities that can be related to coordinates and can therefore be binned by those coordinates (e.g. 5 pixels bins... | g28128 | [
0.04512285068631172,
0.026674466207623482,
-0.002743388991802931,
-0.021008983254432678,
-0.04840106517076492,
-0.0465976819396019,
0.053302206099033356,
-0.07719355821609497,
-0.043961431831121445,
-0.014220239594578743,
0.055304527282714844,
-0.041352733969688416,
0.08527767658233643,
0.... |
<p>I have data that look like this in a 365*804 matrix:</p>
<pre><code> Sample Variant1 Variant2 Variant3
Person1 1/0 0/0 1/1
Person2 0/1 1/1 0/0
Person3 0/0 0/0 0/0
</code></pre>
<p>I want to see if any Variants ar... | g17798 | [
0.0038372466806322336,
-0.02038581483066082,
0.016103124246001244,
-0.04605976864695549,
0.004726250655949116,
-0.08052754402160645,
0.040089428424835205,
-0.01807532273232937,
-0.05285509675741196,
-0.0032719315495342016,
0.014697867445647717,
0.04195127263665199,
-0.0060800667852163315,
... |
<p>I have a dataset that I want to fit according to </p>
<p>$$\log(y) = a + b_1\log(x_1) + b_2\log(x_2) +\cdots + b_k\log(x_k).$$</p>
<p>My statistical package has options to do a linear regression and lognormal. I am not sure which one I should choose.</p> | g61277 | [
0.03223183751106262,
-0.02057136408984661,
-0.0066256094723939896,
0.011991440318524837,
-0.04212382808327675,
-0.0197592880576849,
-0.01712026819586754,
-0.017949216067790985,
-0.03165172040462494,
-0.017828822135925293,
0.009680325165390968,
0.013133544474840164,
0.023630961775779724,
-0... |
<p>It's usually straightforward to do a <code>Power Analysis</code> to compute the <code>minimum sample size</code>, especially <a href="http://www.ats.ucla.edu/stat/r/dae/t_test_power2.htm" rel="nofollow">in R</a> which is my preferred statistical computing environment.</p>
<p>However, I am being asked to conduct a P... | g620 | [
-0.03580566495656967,
-0.018099334090948105,
0.006761808879673481,
-0.0354054719209671,
-0.03166478872299194,
-0.03254391998052597,
-0.058007460087537766,
0.045899394899606705,
-0.06448639929294586,
-0.031179159879684448,
0.08972205966711044,
0.0013084394158795476,
0.02918795868754387,
0.0... |
<p>I have several data related questions I am hoping to get answers to. I have a 4-week intervention (no control group) and all participants are given and pre and post test assessment consisting of two highly reliable, valid, and correlated measures (BAI and BDI). Here are the questions I am trying to answer: </p>
<o... | g61278 | [
-0.024860868230462074,
0.009401960298418999,
0.009950371459126472,
-0.0154578797519207,
-0.03099769540131092,
-0.0035650108475238085,
0.07256020605564117,
0.03753983601927757,
0.004572565667331219,
-0.03547077253460884,
0.006202890537679195,
0.039660315960645676,
0.0042973849922418594,
-0.... |
<p>In my multivariate dataset I have over 100 objects/cases that have been coded on 20 different variables. Several variables are ordinal and several variables are nominal. Is it possible to use non-linear principal components analysis as a dimension reduction technique on this dataset? I am not certain how to approach... | g61279 | [
0.004967141896486282,
-0.038283996284008026,
0.005769869778305292,
-0.06844407320022583,
-0.060837358236312866,
-0.03626227006316185,
0.011434854008257389,
-0.012141125276684761,
-0.06782135367393494,
0.06941564381122589,
0.045296359807252884,
-0.00818287581205368,
0.0014380515785887837,
0... |
<p>I have a large dataset (>300,000 rows) with two variables. y is binary and x is continuous & numeric. I'd like to plot y and add smooth curve against x. I understand that loess(y~x) is a solution, but since I have such a big dataset, it takes too long to run, even if I set the 'cell' parameter to 500.</p>
<p>Us... | g17801 | [
0.053304072469472885,
-0.011960738338530064,
-0.005116316024214029,
-0.0681428387761116,
-0.015796449035406113,
-0.007720325607806444,
0.031103448942303658,
0.0062419516034424305,
-0.01665116846561432,
0.0009671346633695066,
0.035454411059617996,
0.06259890645742416,
0.0909702330827713,
0.... |
<p>I have a series of dollar amounts that are highly right skewed, but are roughly log-normal. i want to put this grouped dollar amount as a predictor variable into a latent class cluster analysis. In this case I'm not sure whether transforming into log-normal makes sense for a predictor variable, as opposed to just bi... | g61280 | [
-0.04121028631925583,
0.024689970538020134,
0.015011392533779144,
-0.06319718807935715,
-0.05990425869822502,
-0.03767675161361694,
-0.020355215296149254,
0.011674855835735798,
-0.038058988749980927,
-0.0260319747030735,
0.006191406864672899,
0.026236290112137794,
0.04216078296303749,
-0.0... |
<p>I was reading the <a href="http://en.wikipedia.org/wiki/Generalized_estimating_equation" rel="nofollow">Wikipedia Article on Generalized Estimating Equations</a>, where I came across the following sentence:</p>
<blockquote>
<p>Parameter estimates from the GEE are consistent even when the covariance structure is m... | g17804 | [
0.06115146726369858,
-0.032526109367609024,
-0.005146813578903675,
0.029259227216243744,
0.027125341817736626,
-0.0029277808498591185,
0.06109604611992836,
-0.009703002870082855,
-0.0360497385263443,
0.0297712329775095,
-0.036143455654382706,
-0.010003981180489063,
-0.03765428438782692,
0.... |
<p>I want to derive the first-order autocorrelation coefficient of an AR(1) process, where the AR(1) process can be expressed as:</p>
<p>$$y_t = \Theta y_{t-1} + u_t$$ with $|\Theta|<1$.</p>
<p>Please give me a hint on how to start with this problem?</p> | g61281 | [
0.03800373151898384,
-0.026938840746879578,
0.004526364151388407,
-0.021708356216549873,
0.044214218854904175,
-0.06565017998218536,
0.07482828199863434,
0.027074109762907028,
-0.0005029063322581351,
-0.0053093042224645615,
-0.012601815164089203,
0.0910901352763176,
0.03015238046646118,
0.... |
<p>I have reviewed a set of papers, each reporting the observed mean and SD of a measurement of $X$ in its respective sample of known size, $n$. I want to make the best possible guess about the likely distribution of the same measure in a new study that I am designing, and how much uncertainty is in that guess. I am ha... | g61282 | [
-0.005861480720341206,
-0.018252594396471977,
-0.019286904484033585,
-0.040808409452438354,
-0.0472116619348526,
-0.018953761085867882,
-0.02026941627264023,
-0.05533261597156525,
-0.03734036907553673,
-0.030250081792473793,
0.013808568008244038,
0.04891492798924446,
0.01962592639029026,
0... |
<p><a href="http://en.wikipedia.org/wiki/Dirichlet_process" rel="nofollow">Dirichlet process</a>, <a href="http://en.wikipedia.org/wiki/Pitman%E2%80%93Yor_process" rel="nofollow">Pitman Yor processes</a> and their variants are special types of distributions whose domain are themshelves a distribution. Is there a name t... | g61283 | [
0.04877163842320442,
0.005658804904669523,
-0.04378974810242653,
-0.0643894150853157,
0.00731230340898037,
0.0017939814133569598,
0.04861995577812195,
-0.016453543677926064,
0.0009865660686045885,
-0.06609107553958893,
0.001747526228427887,
-0.003100103233009577,
0.08145090192556381,
0.010... |
<p>I was asked to calculate a confidence score for a single proportion representing a conversion rate. I saw a lot of documents that calculate confidence <em>intervals</em> for proportions based on the binomial distribution; however I did not see any material for a single conversion (or proportion). If $X \sim Bin(n,p)... | g49351 | [
0.0004508431302383542,
-0.003891478991135955,
-0.015125034376978874,
-0.020004823803901672,
0.003590762848034501,
0.014642195776104927,
-0.0009273976320400834,
0.06827526539564133,
-0.03239442780613899,
-0.016037337481975555,
0.06441513448953629,
-0.004973664879798889,
0.02804289013147354,
... |
<p>I am using a scale which consists of discrete values 0 (normal), 1 (mild), 2 (moderate), 3 (severe). I have used this scale for 200 patients. </p>
<p>I am going to find the correlation of this scale with some continuous variables, these variables also measured for 200 patients. </p>
<p>I don't think I can use mult... | g49806 | [
0.04592113941907883,
-0.036369647830724716,
-0.011427649296820164,
-0.04090975970029831,
-0.03382856026291847,
0.0035299172159284353,
-0.028818542137742043,
-0.0016043527284637094,
-0.005564108956605196,
-0.06481943279504776,
0.009113389067351818,
-0.028207404538989067,
-0.016377834603190422... |
<p>I have a pair of time series that I differenced and now take on values {-1, -0.5, 0, 0.5, 1}. My goal is to test them for Granger causality and discover any lead/lag relationships. Since this requires the time series to be stationary, I ran adf.test on them and was surprised to find that the p-value for both were ... | g61284 | [
0.06957055628299713,
-0.03405264765024185,
-0.026724422350525856,
-0.053517963737249374,
0.06971271336078644,
-0.016613716259598732,
0.07226938009262085,
-0.0029294767882674932,
-0.056388769298791885,
-0.0135123822838068,
0.020284680649638176,
0.0585632398724556,
0.008321000263094902,
-0.0... |
<p>Suppose a discrete random distribution $X$ which takes integer values in some small (but not binary) range, e.g. $[0, 255]$ and whose true pmf is unknown (however, the null hypothesis is that it is uniform). If I draw a large sample $\{x\}$ from this distribution, I can estimate the pmf by counting the number of $x... | g47539 | [
-0.0032286883797496557,
-0.03098544478416443,
-0.032990653067827225,
-0.06442104279994965,
-0.055086441338062286,
-0.011915870010852814,
-0.01273482758551836,
-0.026266561821103096,
-0.04830237478017807,
-0.05518693849444389,
-0.010319818742573261,
0.0009127450757659972,
0.05348558351397514,... |
<p>I have a S-Plus <a href="https://home.zhaw.ch/~brw/index.html?tools" rel="nofollow">library</a> which I'd like to convert to R. I am a programmer, but I don't know anything about S-Plus or R. From my research it seems that they are highly compatibile. Is that true? The code I want to convert only uses core S-Plus li... | g47540 | [
-0.04617473855614662,
-0.02965371496975422,
0.004256473388522863,
-0.07740046083927155,
-0.019585387781262398,
-0.04438968002796173,
0.009748679585754871,
0.052670955657958984,
0.010027441196143627,
0.0036896613892167807,
-0.022678792476654053,
-0.030456535518169403,
0.03231052681803703,
0... |
<p>Suppose I am given two groups of mass measurements (in mg), which are referred to as y1 and y2. I want to do a test to determine if the two samples are drawn from populations with different means. Something like this for example (in R):</p>
<pre><code>y1 <- c(10.5,2.9,2.0,4.4,2.8,5.9,4.2,2.7,4.7,6.6)
y2 <- c(... | g61285 | [
0.011570559814572334,
0.0004632243362721056,
-0.022954000160098076,
-0.0005137035041116178,
0.041327714920043945,
0.013716982677578926,
0.004993988201022148,
-0.0028757373802363873,
-0.04102206230163574,
-0.007541839499026537,
-0.019032731652259827,
0.015348982997238636,
0.02812211588025093,... |
<p>I have run a AMELIA imputation for a data set including missing data. I need to replace the missing point by the result of amelia(). But it content 5 group of imputed values. How can i choose the best one to replace the missing values (to plot a graph of data set after imputing)</p> | g61286 | [
0.07731198519468307,
-0.06797841936349869,
-0.00970566738396883,
-0.0525703951716423,
-0.0034564572852104902,
0.0075678047724068165,
0.011200708337128162,
-0.0383710078895092,
-0.033060282468795776,
0.02617630548775196,
0.01792158931493759,
0.007499228697270155,
0.029911106452345848,
-0.00... |
<p>This might be a very simple question to answer, but for some reason I have just been banging my head against the wall for a little while now. To me, it makes some intuitive sense that $f_{X,Y}(X,Y)$ is same as $f_{X,Y|X}(X,Y|X)$, but I cannot for the life of me figure out how to show it. </p>
<p>However at the same... | g61287 | [
0.03687926381826401,
-0.001108368975110352,
-0.0042017423547804356,
-0.0047779809683561325,
-0.032232433557510376,
-0.05415768548846245,
-0.016343576833605766,
0.02073170244693756,
-0.0023763724602758884,
-0.03503978252410889,
-0.009396086446940899,
0.014064023271203041,
0.023981334641575813... |
<p>Supposing one has a time series from which one can take various measurements such as period, maximum, minimum, average etc. and then use these to create a model sine wave with the same attributes, are there any statistical approaches one can use that could quantify how closely the actual data fit the assumed model? ... | g61288 | [
-0.010353575460612774,
-0.05687032639980316,
-0.0013063800288364291,
-0.025792138651013374,
-0.02724377065896988,
-0.0058425250463187695,
0.06028667464852333,
-0.01256355457007885,
-0.029343724250793457,
-0.02436370775103569,
0.011014185845851898,
0.04145091399550438,
0.056841619312763214,
... |
<p>I have a Linear Dynamical System as in the following graphical model:
<img src="http://i.stack.imgur.com/qUDHu.png" alt="enter image description here"></p>
<p>Every random variable is a scalar; we know $B$ and $x_1$ a priori. $A$ comes from a Gaussian, the variances $R$ and $Q$ come from Inverse Gamma distributions... | g22145 | [
0.013947328552603722,
-0.048708584159612656,
-0.018652766942977905,
-0.06251022964715958,
0.0021267696283757687,
0.025020258501172066,
-0.020001737400889397,
-0.026263665407896042,
0.027153443545103073,
0.010222516022622585,
0.01058835256844759,
0.06866634637117386,
0.03470970690250397,
-0... |
<p>I'm using GPML toolbox by C.E.Rasmussen to solve the basic GP regression problem (presented in the book) with noisy observations. That is to say, estimate the underlying function $f$ of a static noisy mapping </p>
<p>$$y = f(\mathbf{x}) + e, \qquad e \sim \mathcal{N}(0, \sigma^2)$$</p>
<p>from a set of training e... | g280 | [
0.0009397161193192005,
0.012021939270198345,
0.008550507016479969,
-0.00013783748727291822,
0.05685989931225777,
-0.024783769622445107,
0.05631718784570694,
0.026946211233735085,
-0.0753856897354126,
0.0026564758736640215,
-0.037508461624383926,
-0.02415662258863449,
0.045568473637104034,
... |
<blockquote>
<p>Suppose $X$ has probability density function $$f(x, \theta) = \theta e^{-\theta x}$$ when $x > 0$ and $\theta > 0$, and $0$ otherwise; given $\Theta = \theta$. Suppose the prior probability density function of $\Theta$ is $$h(\theta) = 1$$ when $0 < \theta < 1$, and $0$ otherwise. Find the... | g61289 | [
0.027645917609333992,
-0.02068835124373436,
0.01703210547566414,
-0.04179908707737923,
0.006027269177138805,
-0.012669960036873817,
0.032699305564165115,
0.026781296357512474,
-0.04534104838967323,
0.052319612354040146,
-0.00722771231085062,
0.04402831941843033,
0.008863220922648907,
0.001... |
<p>When conducting a repeated measures test where one measures the before/after values for several pairs, how does one account for variance within the pairs themselves? For example lets look at this example of 3 student scores SAT math section as the result of a prep-course.</p>
<p><img src="http://i.stack.imgur.com/A... | g61290 | [
-0.04752110317349434,
0.018944252282381058,
-0.01208634115755558,
-0.008795362897217274,
0.006432646885514259,
0.008557256311178207,
0.00899497326463461,
0.0134871331974864,
-0.03242712840437889,
0.007837921380996704,
-0.043695200234651566,
-0.012774999253451824,
0.006292068865150213,
0.03... |
<p><strong>What are exactly the prerequisites, that need to be fulfilled for AIC model comparison to work?</strong></p>
<p>I just came around this question when I did comparison like this:</p>
<pre><code>> uu0 = lm(log(usili) ~ rok)
> uu1 = lm(usili ~ rok)
> AIC(uu0)
[1] 3192.14
> AIC(uu1)
[1] 14277.29
</... | g49880 | [
-0.007828399538993835,
-0.03405926004052162,
-0.011014369316399097,
-0.026447873562574387,
0.016264207661151886,
-0.016257312148809433,
0.004823629278689623,
-0.014079496264457703,
-0.049564093351364136,
0.015133900567889214,
-0.04370739683508873,
0.04625455662608147,
0.06169414892792702,
... |
<p>I am doing a research work which needs a probability calculation. I'll be grateful if the community cross validates the formula that I have derived using the idea of binary strings and following a great answer by <a href="http://stats.stackexchange.com/users/919/whuber">whuber</a> to <a href="http://stats.stackexcha... | g17815 | [
-0.0535355806350708,
0.022820061072707176,
-0.027912592515349388,
-0.05308292806148529,
-0.004479037597775459,
-0.0674004778265953,
0.024909447878599167,
0.051604755222797394,
-0.03037828952074051,
-0.021646851673722267,
-0.0004286092589609325,
0.07219080626964569,
0.02465081959962845,
0.0... |
<p>I'm new to data analysis. I was wondering how I could recognize hyped (fake) growth and word of mouth (true) growth in Google Trends specifically (but I guess it applies even to stock markets and the rest).</p>
<p>For example, the image below is based on the Google Trends plot when you search for 'iPhone':</p>
<p>... | g61291 | [
0.041886430233716965,
0.054834913462400436,
-0.033069562166929245,
0.00581347243860364,
-0.022577466443181038,
-0.016406908631324768,
0.03113649971783161,
-0.023839017376303673,
-0.0010513337329030037,
-0.03045671619474888,
0.007865785621106625,
-0.012426789849996567,
0.0933951660990715,
0... |
<p>I have breast cancer trial data where, for subgroups 1 and 2, two treatment arms are being compared. The results are:</p>
<ul>
<li>For <strong>subgroup 1</strong>, <code>N=33</code>, median survival in <code>trt1=10mo</code>, median survival in <code>trt2=5.7mo</code>, p-value for difference<code>=0.18</code>. </... | g61292 | [
-0.019812488928437233,
-0.03542213514447212,
-0.027032122015953064,
-0.0034705661237239838,
0.03873336687684059,
-0.001824416103772819,
-0.054307062178850174,
0.039423950016498566,
-0.0819530189037323,
-0.0018383254064247012,
0.00807638093829155,
0.0783352255821228,
0.0476098470389843,
-0.... |
<p>I have some data on successive bets made by customers. I want to see whether there is a statistically significant change in bet stake with each subsequent bet. </p>
<p>The data is skewed, so I have equalized all initial bets to 1. Thereafter, I calculate the proportional change in bet stake. So if someone had a fir... | g17818 | [
-0.05446206405758858,
0.0058972639963030815,
-0.012176712043583393,
-0.02029849775135517,
-0.0011544217122718692,
-0.03452472761273384,
-0.01680418848991394,
0.05289798974990845,
-0.006123129278421402,
0.022849878296256065,
0.06314720213413239,
0.057821884751319885,
-0.017170581966638565,
... |
<p>I have a data which follows gamma distribution and want to know the uncertainty of the parameters of this data. </p>
<ul>
<li>$\text{Data} \sim \text{Gamma} (\alpha, \beta)$</li>
<li><p>Parameters</p>
<p>$\alpha \sim \text{Gamma} (k_\alpha, \theta_\alpha)$</p>
<p>$\beta \sim \text{Gamma}(k_\beta, \theta_\beta)$</... | g34204 | [
-0.014110415242612362,
-0.042459651827812195,
-0.01630396954715252,
-0.08698523789644241,
0.0064322552643716335,
0.04318671673536301,
0.012180022895336151,
0.032831352204084396,
-0.05223061144351959,
-0.0015496633714064956,
0.014802874997258186,
0.020454425364732742,
-0.0060380492359399796,
... |
<p>I am analyzing policy diffusion using panel data, and the inclusion of temporal controls substantially influences my results. I'm wondering if it can theoretically make a difference for the estimates of my <strong>other</strong> variables if I include common time dummies for all units of observation, or if, e.g. I u... | g17820 | [
0.0068672350607812405,
0.04407438635826111,
-0.006104153580963612,
-0.007358476519584656,
0.0466039776802063,
0.004328462295234203,
0.02385476417839527,
0.03155946359038353,
0.03304510563611984,
-0.012016847729682922,
-0.015720799565315247,
-0.01493785623461008,
0.03238219767808914,
0.0080... |
<p>layman here...</p>
<p>I have some sets of several hundred scores that are not distributed normally. I want to normalize these scores onto a percentile scale.</p>
<p>The mean-median-mode for these look like this:</p>
<pre><code>3-2-0,
1-1-0,
9-3-0,
1-5-5,
</code></pre>
<p>I have calculated the variance/std dev a... | g24777 | [
0.0021969201043248177,
0.003599629970267415,
-0.017932085320353508,
-0.01572912186384201,
0.010315855965018272,
0.04353669658303261,
0.014099798165261745,
0.029095016419887543,
0.009265138767659664,
-0.04160277545452118,
0.03319094330072403,
-0.004825292620807886,
0.04508340731263161,
-0.0... |
<p>I'm trying to teach myself about cross-validation – I'm new at this – and I'm having a conceptual problem.</p>
<p>I'm reading the book "Classical and Modern Regression" by Myers, chapter four, which is on cross-validation for model selection, specifically, the section on the PRESS statistic. The intuitive definitio... | g17822 | [
0.04333300143480301,
-0.018925592303276062,
0.004271632060408592,
-0.00006392750947270542,
0.023409033194184303,
0.022661205381155014,
0.048611029982566833,
0.04215944558382034,
-0.05304262787103653,
0.036130499094724655,
-0.03003329411149025,
0.023856939747929573,
0.016392532736063004,
-0... |
<p>I have survival data with RNA expression. A lot of the data is censored. Is there an R package that does a proportional hazards model where the number of covariates is much larger than the number of samples? </p>
<p>The only one I could find is glcoxph. Are there any others?</p> | g17823 | [
0.03032744862139225,
-0.0532669797539711,
0.013141590170562267,
-0.028732096776366234,
-0.010309603065252304,
-0.001799092860892415,
-0.060440484434366226,
-0.0023650408256798983,
-0.012950469739735126,
0.03078017570078373,
0.0373411700129509,
-0.0036520157009363174,
0.0750114768743515,
-0... |
<p>I am concerned with simulating data for a linear regression model. I need to control the means, variances, and correlations (covariances) between the predictors and the criterion variable. In addition, I need to be able to vary the explained variances ($R^2$). It is obvious to me that the latter must be a function o... | g61293 | [
-0.003220146521925926,
-0.03847188875079155,
-0.012056839652359486,
-0.03659309446811676,
0.016575578600168228,
-0.03344948589801788,
0.0019339980790391564,
0.012521387077867985,
-0.015423987060785294,
-0.013845955021679401,
-0.012286704033613205,
0.026113267987966537,
0.03372211754322052,
... |
<p>I would like to measure the impact of an intervention using a form of time series or some related technique (like segmented regression). I would like to use the Schools and Staffing Survey, which assesses my variable of interest over time, however, the respondents are different at each time point. I assume differen... | g61294 | [
-0.04039013385772705,
0.02111046202480793,
0.006906477734446526,
-0.07785056531429291,
-0.014371165074408054,
-0.021183887496590614,
0.020969273522496223,
0.04876153916120529,
0.03154345601797104,
-0.013849646784365177,
0.05757305771112442,
-0.014098391868174076,
0.014007732272148132,
0.03... |
<p>I need to summarize possible approaches (as well as their pros and cons) to the problem of statistical series prediction. </p>
<p>It's pure theoretical question, an example below was given only for convenience and specificity. </p>
<p>First of all, sorry for the term 'statistical series'. Question originally ask... | g61295 | [
0.00008958047692431137,
0.03934451565146446,
0.00576782738789916,
-0.047451287508010864,
-0.038683000952005386,
-0.047097865492105484,
0.023192543536424637,
0.004336254205554724,
-0.0301809199154377,
-0.04376617819070816,
0.008309362456202507,
0.043764133006334305,
0.06698723137378693,
-0.... |
<p>For the purpose of this question, please consider me a stats newbie.</p>
<p>I'm working on a (very fun!) research project which involves estimating a pdf of "personal values" -- i.e. how much a certain person values a certain good they can buy.</p>
<p>I wanted to find the functional form of the PDF so that I could... | g61296 | [
0.008830349892377853,
-0.03393647447228432,
-0.009564640931785107,
-0.07135973870754242,
-0.037958428263664246,
-0.013863069005310535,
-0.006736634764820337,
-0.00037230391171760857,
-0.008028038777410984,
-0.02297673001885414,
-0.012383861467242241,
-0.04079371690750122,
0.09027229994535446... |
<p>I am running two different advertisements served up randomly. I monitor how many people respond to each advertisement. I am trying to determine if one ad is better than the other. If I run a Fisher's significance test on the results I can find if the null hypothesis can be rejected at any point in time.</p>
<p>I... | g34207 | [
0.023438749834895134,
-0.005675481166690588,
-0.00013912271242588758,
-0.016247984021902084,
0.026513822376728058,
-0.048346612602472305,
0.033025261014699936,
0.00044002721551805735,
0.03212147206068039,
-0.034755587577819824,
0.02693330869078636,
0.03723478689789772,
-0.00874831061810255,
... |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.