question stringlengths 37 38.8k | group_id stringlengths 2 6 | sentence_embeddings listlengths 768 768 |
|---|---|---|
<p>I see some similar threads, but no answer that I know how to apply to this question. I wish to create a variance matrix for a (pseudo)random matrix $X$ with dimensions $K \times N$, where each row $k$ represents $N$ draws of a random variable with mean $\mu_k$, $\sigma^2_k=10$, and 10 was arbitrarily selected. The g... | g60662 | [
-0.06087470054626465,
0.008782865479588509,
-0.008939984254539013,
-0.05352094769477844,
0.007144968491047621,
-0.009796318598091602,
0.0424342155456543,
-0.010687952861189842,
-0.039644379168748856,
-0.01287858746945858,
-0.05045129731297493,
0.022732770070433617,
0.005658555775880814,
0.... |
<p>From <a href="http://en.wikipedia.org/wiki/Effect_size" rel="nofollow">Wikipedia</a></p>
<blockquote>
<p><strong>Given a sufficiently large sample size, a statistical comparison will always show a significant difference unless the population effect size is exactly zero.</strong></p>
<p>For example, a sample ... | g45404 | [
0.01123731303960085,
0.007949224673211575,
0.022051742300391197,
-0.0460759773850441,
0.0008492805645801127,
-0.015806376934051514,
-0.0025789944920688868,
0.07374110817909241,
-0.025888754054903984,
-0.052839506417512894,
0.03900062292814255,
0.0009205807582475245,
0.02233061194419861,
0.... |
<p>I am trying to determine the factor structure of a set of 84 items. Exploratory factor analysis using varimax rotation was conducted to estimate the underlying factor structure for the sample data. Two rounds of exploratory factor analysis were conducted. Items with loading below the generally accepted 0.60 threshol... | g60663 | [
0.006427690852433443,
0.029733898118138313,
0.01896495930850506,
-0.07475067675113678,
0.020248351618647575,
-0.013669044710695744,
0.03529186546802521,
-0.014254903420805931,
-0.009769582189619541,
0.009454061277210712,
-0.024803072214126587,
-0.010726950131356716,
0.013554985634982586,
-... |
<p>I have started to use the <code>GENLIN</code> procedure in SPSS more than any of the specific dialogues, but I don't understand the Scale parameter or why it has the effects it does on the regression results.</p>
<p>Here's an SPSS example: <em>code block 1</em></p>
<p>Normally, if I wanted to see if <em>set</em> h... | g16880 | [
0.021196559071540833,
-0.012845458462834358,
-0.009646880440413952,
-0.034670233726501465,
0.05800653249025345,
0.027814989909529686,
0.019084544852375984,
0.03253648430109024,
-0.05233268439769745,
0.0049714092165231705,
-0.0031211927998811007,
0.00010228981409454718,
0.06874226778745651,
... |
<p>I have 10 independent locations (separated by at least 5 km) where I have collected abundance data for 17 species of birds. In particular, I want to look for correlations between one particular species and the 16 other species. Each site was sampled multiple times (separated by 2-8 weeks), some only 17 times while o... | g60664 | [
0.004357011057436466,
-0.03368131071329117,
-0.015698576346039772,
-0.039622411131858826,
0.007821719162166119,
-0.005500560626387596,
0.02707560732960701,
0.03460033982992172,
-0.005001605488359928,
-0.011175560764968395,
0.01708223484456539,
-0.031035734340548515,
0.0032536815851926804,
... |
<p>I need to write a report on what is Monte Carlo method suitable for and for what it is not suitable for, however, I can't find a lot of material regarding this information. What is it suitable for apart for integration, physics and travelling salesman problem? And for what it is not?</p> | g60665 | [
0.062084462493658066,
0.08484672755002975,
0.00819938350468874,
-0.06182011216878891,
-0.04931585490703583,
-0.03039374202489853,
0.03923794999718666,
0.04072906821966171,
-0.04336884990334511,
0.033241789788007736,
-0.011425355449318886,
-0.012885690666735172,
0.04801250249147415,
-0.0171... |
<p>I have two test groups that conducted an online task measuring response times (avg, avg(congruent), avg(incongruent)). I expected one group to be faster than the other but it turned out exactly the opposite way (significant). So now I'm trying to find one or more factors that are responsible for this unexpected outc... | g16882 | [
0.039580270648002625,
-0.07553554326295853,
-0.01065915822982788,
-0.07347376644611359,
0.03889553248882294,
-0.013776414096355438,
0.027931218966841698,
0.014692866243422031,
0.016677001491189003,
0.007438326254487038,
0.039201460778713226,
-0.030997484922409058,
0.0022189358714967966,
0.... |
<p>Would there be any problem with using principal component analysis (e.g. for reduction of dimensionality) so that principal components scores could be used as predictors in a mixed-model? For non-mixed models this strategy is frequently applied (principal component regression) but I am not sure if it is applicable i... | g509 | [
-0.020959405228495598,
-0.04938315227627754,
0.023631691932678223,
-0.040245942771434784,
-0.012110902927815914,
-0.0015144076896831393,
0.08738251030445099,
0.035145681351423264,
-0.029083767905831337,
-0.02462107129395008,
0.06172146648168564,
-0.013386139646172523,
-0.00451815826818347,
... |
<p>I have recently been reading a lot on this site (@Aniko, @Dikran Marsupial, @Erik) and elsewhere about the problem of overfitting occuring with cross validation - (Smialowski et al 2010 Bioinformatics, Hastie, Elements of statistical learning).
The suggestion is that <em>any</em> supervised feature selection (using... | g60666 | [
-0.006126757711172104,
-0.024953693151474,
0.028567710891366005,
-0.0022079581394791603,
0.03093944862484932,
0.009470932185649872,
0.08707273751497269,
-0.008263476192951202,
-0.040077995508909225,
0.02642407827079296,
0.027861936017870903,
0.020960835739970207,
0.004063058644533157,
0.04... |
<p>I am just wondering if there is a way to calculate the distances between the centroids generated by Primer 6 in a MDS plot. I am trying to find if the centroid distances change beween samples but I can't find a way to obtain values from the program. </p> | g9621 | [
0.021671520546078682,
-0.0281416904181242,
-0.006891696713864803,
-0.05507614091038704,
-0.0455586314201355,
-0.04050826281309128,
0.007461031898856163,
-0.016803838312625885,
-0.00009968700760509819,
-0.024640128016471863,
-0.036396510899066925,
-0.00618569552898407,
0.07185761630535126,
... |
<p>As per my understanding here's the what/why/when of the following hypotheses tests in a crude sense:</p>
<ul>
<li><strong>t-test</strong>: Used when comparing means between two samples</li>
<li><strong>ANOVA (one way)</strong>: Used when you have one dependent variable and one independent (i.e., categorical) varia... | g60667 | [
0.007948366925120354,
0.0019208420999348164,
0.006382985506206751,
0.0022670805919915438,
-0.016569413244724274,
-0.024692581966519356,
0.0017728022066876292,
0.023754309862852097,
-0.033464059233665466,
-0.021003080531954765,
-0.012299413792788982,
-0.01655283384025097,
0.03029162622988224,... |
<p>This is my first post ever so I beg you please forgive me any mistake (I'm also super newbie in stats).
I have this dataset that comes from interviews filled by users (divers) about their perception on resources (six shark species) population trends across four decades. Every user was asked to state their perceptio... | g60668 | [
0.005964496172964573,
-0.04206410050392151,
0.011538365855813026,
-0.007913384586572647,
0.002542458940297365,
0.005106208845973015,
0.0604705810546875,
0.042493995279073715,
-0.05199945718050003,
0.024220969527959824,
0.03438391163945198,
-0.003919489681720734,
-0.004963807296007872,
0.07... |
<p>I would appreciate if someone could help me in translating the following R command into a mathematical equation:</p>
<pre><code>lme(score ~ factor(timeslot), random=~1|subjectid, data=a)
</code></pre>
<p>For each subject there are observations at 6 different times (timeslots) during a day.</p> | g16889 | [
-0.012122184038162231,
-0.00026646110927686095,
-0.012237699702382088,
-0.05400292947888374,
-0.013993312604725361,
-0.041524920612573624,
0.023085353896021843,
-0.03404994681477547,
-0.07563260197639465,
-0.028393112123012543,
-0.01810692809522152,
0.021438803523778915,
0.012461927719414234... |
<p>I have a group of binary tasks performed by multiple subjects. Every task can be either performed right or wrong (i.e.,1/0). My goal is to predict the accuracy of future task given the performance on previous tasks. As tasks considered to be independent, I thought that it makes sense to average the accuracy by makin... | g60669 | [
0.0024667365942150354,
-0.04445366561412811,
0.02326662465929985,
-0.020469676703214645,
0.007175262086093426,
-0.034976013004779816,
0.03467706963419914,
0.027004459872841835,
-0.04422629252076149,
0.009937492199242115,
0.046515047550201416,
0.0033453693613409996,
-0.0344335213303566,
0.0... |
<p>I have a dataset of some 100 samples, each with >10,000 features, some of which highly correlated. Here's what I am doing currently.</p>
<ol>
<li><p>Split the data set into three folds.</p></li>
<li><p>For each fold,<br>
2.1 Run elastic net for 100 values of lambda. (this returns a nfeatures x 100 matrix)<br>
2... | g60670 | [
-0.02891802042722702,
-0.00020945316646248102,
0.015699416399002075,
-0.033413369208574295,
0.046465978026390076,
-0.03093932941555977,
-0.0044608223251998425,
0.06132468581199646,
-0.040829531848430634,
-0.0038372953422367573,
-0.004148362670093775,
-0.01221324410289526,
0.05157878994941711... |
<p>My question regards statistics as applied to text mining. </p>
<p>I have used substring matching to determine the predicted set of keywords. I then classify those keywords into broader groups. </p>
<p>Given a body of text, I want to draw a single group based on the keywords. I used the Multinomial-Dirichlet to do ... | g60671 | [
-0.0009404250886291265,
0.0015626384411007166,
-0.010290127247571945,
-0.03578490391373634,
-0.023396963253617287,
-0.055378567427396774,
-0.03425581753253937,
-0.015174449421465397,
-0.01614023558795452,
-0.004670746624469757,
0.01854918897151947,
-0.03476991504430771,
0.055137477815151215,... |
<p>I am working with a time series (discrete) that has ideally 1 value per time stamp. In some cases, we are seeing multiples that have a wide range all recorded with the same time stamp. </p>
<p>Up to now, we had been averaging the data but have found quite a few instances of very big ranges. </p>
<p>Should we inste... | g46477 | [
0.004750899504870176,
0.008688544854521751,
-0.008396366611123085,
-0.04325592890381813,
-0.028537027537822723,
-0.011162953451275826,
0.06351590156555176,
-0.015491172671318054,
-0.027835702523589134,
-0.012712095864117146,
-0.021274076774716377,
-0.047100141644477844,
0.04662998765707016,
... |
<p>I'm using 2 kind of logistic regression - one is the simple type, for binary classification, and the other is ordinal logistic regression. For calculating the accuracy of the first, I used cross-validation, where I computed the AUC for each fold and than calculated the mean AUC.
How can I do it for the ordinal logis... | g60672 | [
0.013696621172130108,
-0.013644663617014885,
-0.006277956999838352,
-0.05119043588638306,
0.03713824227452278,
-0.06370285898447037,
0.019331691786646843,
-0.0029289163649082184,
-0.045581310987472534,
-0.006454607006162405,
0.011783472262322903,
0.05801086872816086,
0.0847746953368187,
-0... |
<p>The question is similar to <a href="http://stats.stackexchange.com/questions/7727/how-to-correlate-two-time-series-with-gaps-and-different-time-bases">How to correlate two time series with gaps and different time bases?</a> but with regular sample frequency and identical time base between two time series.</p>
<p>Sa... | g38061 | [
0.02862085960805416,
0.0006507968064397573,
0.01679067313671112,
0.003222568891942501,
0.023053821176290512,
-0.028773989528417587,
0.023469315841794014,
-0.033722665160894394,
0.02284974232316017,
0.011551063507795334,
0.036283910274505615,
-0.04809156060218811,
-0.01413700357079506,
0.03... |
<p>I'm running a 3-factor (Between by Between by Within) ANOVA with the correlation structure modeled using a Random Intercept and Gaussian Serial Correlation. I have the following variables:</p>
<p>Dependent variable: Bodyweight </p>
<p>Independent: </p>
<p>Size - size of the subject (between). 2 levels: normal a... | g60673 | [
0.004955901764333248,
-0.05722065269947052,
-0.01641346886754036,
0.01761329174041748,
-0.0707491859793663,
-0.034286852926015854,
0.00712048914283514,
0.013974475674331188,
-0.03759896010160446,
-0.01720113679766655,
-0.0024716993793845177,
-0.010180188342928886,
-0.057736072689294815,
0.... |
<p>I have a data set with two categorical nominal variables (both with 5 categories). I would like to know if (and how) I am able to identify potential correlations among categories within these variables.</p>
<p>In other words whether for example the results of category 1 in variable 1 show a strong correlation with ... | g16900 | [
-0.0014689085073769093,
-0.036229208111763,
0.01856125146150589,
-0.05559829622507095,
0.01227489486336708,
-0.045494187623262405,
0.03041926585137844,
-0.013886092230677605,
-0.033116620033979416,
-0.022147782146930695,
-0.016912806779146194,
0.01589646190404892,
0.01971898041665554,
0.05... |
<p>I need to select a statistical test in order to answer the question of whether the <code>TASR238</code> genotype is a good predictor of the ability to taste PTC (phenotype)</p>
<p>Here are the data I collected for my lab report:</p>
<pre><code> PTC taster
Genoty Strong Weak Non
T/T 10 4 ... | g16902 | [
-0.029169466346502304,
-0.011278623715043068,
0.019505564123392105,
-0.014908118173480034,
0.010177637450397015,
-0.07054794579744339,
0.04426136985421181,
0.06037779152393341,
-0.012664359994232655,
0.014050938189029694,
0.007384944707155228,
0.03805059939622879,
0.006449279375374317,
0.0... |
<p>I have a simple random sample (SRS) $S$ of size $n$ drawn from a population $D_1$ containing $N_1$ members. A new set $D_2$ with $N_2$ members is added to the population. I would like to create a new set $S'$ that is a SRS from $D_1 \cup D_2$. </p>
<p>One strategy that won't work is to draw a SRS of size $nN_... | g16903 | [
-0.025052377954125404,
0.0237931739538908,
-0.0160340815782547,
-0.036864399909973145,
-0.05287688970565796,
-0.036816392093896866,
-0.01250729151070118,
-0.0291330236941576,
-0.01777574047446251,
-0.010026419535279274,
-0.01334856916218996,
0.014240515418350697,
0.043042171746492386,
0.02... |
<p>Binomial logistic regression has upper and lower asymptotes of 1 and 0 respectively. However, accuracy data (just as an example) may have upper and lower asymptotes vastly different to 1 and/or 0. I can see three potential solutions to this: </p>
<ol>
<li>Don't worry about it if you are getting good fits within th... | g60674 | [
0.029714588075876236,
-0.06593730300664902,
0.01312918309122324,
0.01344401203095913,
0.020408106967806816,
-0.03547896817326546,
0.023487746715545654,
-0.018788499757647514,
-0.04071898013353348,
-0.05019456520676613,
0.042509160935878754,
-0.016667259857058525,
0.0701313391327858,
-0.021... |
<p>I am running a multiple regression of the form <em>Y</em> = $\beta_0$ + $\beta_1$*$X_1$ + $\beta_2$*$X^2_1$ + $\beta_3$*$X_2$ + $\beta_4$*$X_3$ on a time-series dataset. I want to plot the relationship between <em>Y</em> and $X_1$ based on this equation such that I get a curve after taking into account the effects ... | g16905 | [
0.0522012859582901,
-0.0568515807390213,
-0.003104778937995434,
0.01927468180656433,
-0.032790407538414,
-0.026678336784243584,
0.03832399845123291,
0.03290699049830437,
-0.0221328753978014,
-0.0159224234521389,
0.02447742037475109,
0.032209090888500214,
0.02167687937617302,
-0.00017508791... |
<p>Struggling with how to start this question:</p>
<p>A factory processes chickens with masses between 1.5 and 2.5kg. "Natural" chickens have masses equally spread across this range. However, "GM" chickens have masses between 2.3 and 2.4kg.</p>
<p>If a factory produces 10 million chickens per year, how many GM chicke... | g60675 | [
-0.004592313896864653,
0.06398354470729828,
-0.0013692890061065555,
-0.006265685427933931,
-0.011025366373360157,
-0.02590939961373806,
0.05195871368050575,
0.0019261654233559966,
-0.07384388148784637,
-0.012696124613285065,
-0.050513558089733124,
0.009513845667243004,
0.00968784000724554,
... |
<p>I would like to run some two dimensional Kolmogorov-Smironov tests to determine whether a two-dimensional distribution fits with a reference.</p>
<p>Is there any package or application that I could I use in a relatively straightforward fashion? Or is there a different algorithm that is preferrable? I have just a ba... | g60676 | [
0.0621165856719017,
-0.05634625628590584,
-0.008339275605976582,
-0.011835425160825253,
-0.08175324648618698,
-0.004802515730261803,
0.01762428879737854,
0.06003379449248314,
-0.03701498359441757,
0.022962065413594246,
0.008087389171123505,
-0.011769584380090237,
0.042533617466688156,
0.01... |
<p>Given a time series, I am trying to determine whether the underlying stochastic process is a martingale or not. Until now, I have deduced that since I know that the process is always bounded after a deterministic time, if I can prove that it is a Brownian motion, I will be done. Is there a standard test for this?</p... | g60677 | [
0.013922194018959999,
0.001217701705172658,
0.0327407605946064,
0.019249236211180687,
-0.06484019011259079,
-0.034716371446847916,
0.031159665435552597,
0.001896937028504908,
-0.02863761968910694,
-0.04562358185648918,
0.012707552872598171,
0.06046207994222641,
0.015216474421322346,
0.0402... |
<p>For dealing with multiple testing, Benjamini and Hochberg (1995) assume that the tests are independent. Benjamini and Yekutieli (2001) show that (1) the 1995 result also holds under (I think) weaker conditions and that (2) including the factor $\Sigma^m_{i=1}\frac{1}{i}$ makes the procedure applicable for any depend... | g60678 | [
0.08417099714279175,
-0.015361202880740166,
0.0011252048425376415,
0.08057691901922226,
-0.01784362457692623,
-0.044571857899427414,
0.04953464865684509,
0.028053829446434975,
-0.025857551023364067,
-0.032409872859716415,
-0.012679599225521088,
-0.012048427015542984,
-0.0571339949965477,
0... |
<p>The Cox model does not depend on the times itself, instead it only needs an ordering of the events. How come it doesn't need the time, as all of the models I've seen so far are dependent on the exact time point and/or interval?</p> | g393 | [
-0.028826888650655746,
0.018915193155407906,
0.02185184322297573,
0.0043068393133580685,
0.03197392076253891,
-0.02845996804535389,
0.0010796256829053164,
0.02637205831706524,
-0.01915973424911499,
-0.02732500620186329,
-0.007348208222538233,
-0.052725549787282944,
0.053233448415994644,
-0... |
<p>This question is a follow-up from a previous question of mine <a href="http://stats.stackexchange.com/questions/58220/what-distribution-does-my-data-follow/58241#comment111936_58241">here</a>. Thanks to @Glen_b, @gung and @rbatt for teaching me so many new things yesterday. It was mentioned in passing that mixture d... | g48533 | [
-0.0069448743015527725,
-0.07569717615842819,
0.005249824374914169,
-0.07480964809656143,
0.0028108153492212296,
-0.05161884054541588,
0.05226410552859306,
-0.007801169529557228,
-0.014777949079871178,
-0.057876914739608765,
-0.04305470734834671,
-0.014435767196118832,
0.05106401816010475,
... |
<p>I want to learn about Receiver-Operator-Characteristic curves, and metrics. I have read through online webpages with some basics, and I have used MATLAB built-ins to create ROC plots. It tells me about area sums. I have also looked at the JMP module for classification and for Logistic plot which make ROC plots.</... | g60679 | [
0.04530322924256325,
-0.021773645654320717,
-0.009249445050954819,
-0.05713881924748421,
-0.03799596056342125,
-0.038003116846084595,
0.04285737872123718,
-0.015971539542078972,
-0.03850647807121277,
-0.05090329423546791,
0.0008419458754360676,
0.03079904429614544,
0.10431357473134995,
-0.... |
<p>I have a specific problem which I'm surprised I don't find answers on-line and I hope somebody here has a good suggestion for me. I'm working with a large data set which I'm clustering into specific groups using custom cluster densities. So the original space is quite heterogeneous and has a large number of feature.... | g8101 | [
-0.010910087265074253,
0.005444762762635946,
-0.008851069957017899,
-0.02313908375799656,
-0.030230050906538963,
-0.07151084393262863,
0.017990827560424805,
0.011273018084466457,
-0.02970094047486782,
-0.0012803064892068505,
0.08562981337308884,
0.0041275713592767715,
0.11056337505578995,
... |
<p>I'm attempting to run a LCGA and GMM analysis in R, but I'm not sure how to go about it. The data I have is pretty simple, so let me explain that first.</p>
<p>The dataset is provided by a number of patients who have given item responses (on a Likert scale from 0 to 4) to some questionnaire item at five different t... | g16908 | [
-0.0032183791045099497,
-0.046414460986852646,
-0.0012344432761892676,
-0.05304315686225891,
0.007354997098445892,
-0.014254546724259853,
0.07183632999658585,
-0.012130334042012691,
-0.038794662803411484,
-0.029308343306183815,
-0.003375431289896369,
0.009055663831532001,
0.02918029390275478... |
<p>I have a set of data, counts versus time.
The whole data looks like this </p>
<p><img src="http://i.imgur.com/XpBbkab.png" alt="data"></p>
<p>Here is a sample </p>
<pre><code> x y
[ -0.9 0. ]
[ -0.8 4. ]
[ -0.7 5. ]
[ -0.6 1. ]
[ -0.5 9. ]
[ -0.4 8. ]
[ -0.3 10.... | g60680 | [
0.05333586782217026,
0.043834980577230453,
-0.019464772194623947,
-0.05379920080304146,
0.01862182281911373,
-0.02524472028017044,
0.04191988706588745,
-0.03997871279716492,
-0.08269266784191132,
-0.02736092545092106,
-0.0063448077999055386,
0.026620429009199142,
0.017363712191581726,
0.02... |
<p>I am using the famous <a href="http://quanttrader.info/public/testForCoint.html" rel="nofollow">conintegrated pairs</a> tutorial to just different stocks for cointegration. The adf.test yeilds perfect cointegration, which I feel must be incorrect. Here is why:</p>
<p>When I run adf.test() on a cumsum of a random se... | g60681 | [
0.05547218769788742,
-0.03320632502436638,
-0.034299809485673904,
-0.04652570188045502,
0.05713168904185295,
-0.011510848999023438,
0.051998674869537354,
0.011094732210040092,
-0.015391837805509567,
-0.009360448457300663,
0.005069291219115257,
0.02930735982954502,
0.03844435140490532,
-0.0... |
<p>i'm making experiments using app. 5000 labeled dataset.i'm trying different supervised ML algorithm to evaluate the results.The vector size is 13 with the labels (totally 12 features+1 label) and i have 15 vector of labeled "flower" class. experiments consist of all data set using 10k cross validation. All features ... | g9627 | [
0.00693453848361969,
-0.05127425491809845,
0.023028356954455376,
-0.025162244215607643,
0.023598017171025276,
-0.058609914034605026,
0.06541689485311508,
0.025629034265875816,
-0.044822607189416885,
-0.005397537723183632,
-0.0012720429804176092,
0.07898908853530884,
0.0675525888800621,
0.0... |
<p>I have a dataset with 1206 deputies from two different chambers (1998 and 2002, respectively). In addition, there are 18 parties, and some deputies are in both chambers (the ones who were reelected). I am interested in the relation between party discipline (in a scale from 0 to 100) and the probability of geting app... | g60682 | [
0.016191305592656136,
-0.04968418553471565,
0.0004969500587321818,
-0.015502563677728176,
0.012908054515719414,
0.011938782408833504,
0.022494379431009293,
0.027036532759666443,
-0.004790958948433399,
-0.042341042309999466,
-0.010527433827519417,
-0.007570992223918438,
0.019357506185770035,
... |
<p>I am analysing data on events that I have categorized into groups.</p>
<p>So, for instance, say I have 3000 events categorized into 5 groups, which we call A to E.</p>
<p>I will have something like</p>
<pre><code> Event | Group | Time
--------+-------+-------
1 | A | 0
2 | A | ... | g16911 | [
-0.019301757216453552,
0.05027492716908455,
-0.007434913422912359,
-0.03718337044119835,
0.015139765106141567,
-0.07011231780052185,
0.06071769818663597,
0.022565530613064766,
-0.05188088119029999,
0.004145822487771511,
-0.033151429146528244,
0.015493659302592278,
0.02432132512331009,
0.03... |
<p>I have a very simple question to ask, but I can't figure this on my own.
I have two samples: sample A with only three data points, and sample B with hundreds of points. For each sample I measure the median of certain quantity.
Now my question is, what is the error associated to the median?
I can consider the quartil... | g16912 | [
-0.005870044231414795,
-0.06736607849597931,
-0.038882382214069366,
-0.04406118765473366,
0.03777612745761871,
0.03526141121983528,
-0.002823576796799898,
0.02441774494946003,
-0.0485045351088047,
-0.008578556589782238,
0.007884991355240345,
0.055913377553224564,
0.041828304529190063,
0.00... |
<p>I have two images and I am trying to calculate the disparity between them using sum of squared distances and reconstruct disparity in 3D space. Do I need to rectify the image before calculating disparity?</p>
<p>The following are the steps that I have done so far for disparity map computation(I have tried with rect... | g60683 | [
0.03308835253119469,
-0.037972599267959595,
0.00012172837159596384,
0.01004885882139206,
-0.037750400602817535,
-0.0008757984032854438,
0.014920019544661045,
0.08180786669254303,
-0.027356060221791267,
-0.008568202145397663,
0.034566376358270645,
0.05689292401075363,
0.0889386534690857,
-0... |
<p>I have a monthly series of a moving average , and I want to reconstruct their original series from a simple moving average that I have. I happen to know the window of averaging.</p>
<p>Am I able to either reconstruct or estimate the original series from their moving average?</p>
<p>And in the case I don't have all... | g23077 | [
-0.009154108352959156,
-0.050372008234262466,
0.003145369468256831,
0.0063398792408406734,
-0.08028464764356613,
-0.03394924849271774,
-0.0076041747815907,
0.025794975459575653,
-0.02275381237268448,
-0.004266309551894665,
-0.023299070075154305,
0.05108807235956192,
0.034129850566387177,
0... |
<p>I have a time series from which i select a random point. I randomly pick a direction "Up" or "Down" and i place two targets. When i reach either of these targets, i increment the counter for "Target 1 Reached" or "Target 2 Reached" depending on which is reached first.</p>
<p>Target 1 is always set at 1 +/- value at... | g16915 | [
0.013237743638455868,
-0.022020487114787102,
0.007678688038140535,
-0.051195960491895676,
0.012330754660069942,
-0.0019253611098974943,
0.05031195282936096,
0.001578352996148169,
-0.04544554650783539,
-0.01602078601717949,
-0.030482126399874687,
0.08606173098087311,
0.08783263713121414,
0.... |
<p>I'm trying to create a way to link letters from a text to a position between 1 to 255.</p>
<p>For example, the text is : "stackexchange"
I would like to link every letter to a number between 1 and 255. The same word should have the same output and the overall should be uniform (if I give lots of input, I would like... | g60684 | [
-0.028729459270834923,
-0.008100281469523907,
-0.01118967030197382,
-0.15742677450180054,
0.010984721593558788,
-0.041573263704776764,
0.003924846649169922,
0.03557613864541054,
-0.01255470048636198,
-0.04525081813335419,
-0.006601979490369558,
-0.02202618308365345,
-0.03330237790942192,
-... |
<p>Since it has been some time when i looked into support vector machines and i am facing now to implement the classification step of a trained svm model i would like to ask whether someone could point out how the actual classification step is carried out (assuming i would like to port that step to some low level langu... | g16916 | [
-0.003930749371647835,
-0.03181299939751625,
-0.007281457539647818,
0.0038153165951371193,
-0.009297958575189114,
-0.040078483521938324,
0.016779962927103043,
0.043431639671325684,
-0.05177986994385719,
0.006628212984651327,
-0.025924980640411377,
0.0693025216460228,
0.03308502212166786,
0... |
<p>I am interested in comparing the amount of variability within 8 different samples (each from a different population). I am aware that this can be done by several methods with ratio data: F-test equality of variance, Levene test, etc.</p>
<p>However, my data is circular/directional... I have done some research and f... | g60685 | [
0.048462722450494766,
-0.0693204328417778,
-0.006748563144356012,
-0.038393184542655945,
-0.01245624478906393,
-0.03968960419297218,
0.05999278277158737,
-0.026089757680892944,
-0.02131161093711853,
-0.0015188392717391253,
0.03886089473962784,
0.021198241040110588,
0.013592219911515713,
0.... |
<p>I am trying to compare the outputs of k-means algorithm coded by me and the outputs of R's <strong><code>kmeans</code></strong>. Since the objective of the algorithm is to minimize the total within cluster sum of squares (WCSS), I have to look at the <code>withinss</code> output of <strong><code>kmeans</code></stron... | g60686 | [
-0.02812594547867775,
-0.05450810492038727,
-0.013937195762991905,
0.022373421117663383,
-0.01853574812412262,
-0.07095808535814285,
-0.008719857782125473,
-0.009935504756867886,
-0.013575469143688679,
0.013874944299459457,
0.017935607582330704,
0.07012160122394562,
0.06696174293756485,
0.... |
<p>Would $E( E(Y|A) | B) = E(Y|A,B)$? How does one show this? Intuitively, it make sense that conditioning on this one at a time would result in the same thing as conditioning all at once. </p> | g60687 | [
0.020796632394194603,
-0.02372696064412594,
0.0019593865144997835,
0.002058521844446659,
0.07269777357578278,
-0.05902395397424698,
0.10531066358089447,
0.0542316734790802,
0.03502897173166275,
0.017005641013383865,
-0.03620094433426857,
0.032142773270606995,
0.03211513161659241,
0.0850302... |
<p>I'm doing some regression using neural net(using MLP implementation from <a href="http://deeplearning.net/tutorial/mlp.html" rel="nofollow">http://deeplearning.net/tutorial/mlp.html</a>, I used my own but it produced the same results before I opted for this one), standard SGD with backpropagation, learning rate 0.01... | g60688 | [
-0.014909159392118454,
0.030703455209732056,
-0.02901552990078926,
-0.04403526708483696,
0.05656430497765541,
-0.04713812470436096,
0.0702066645026207,
0.04882686212658882,
-0.040686190128326416,
-0.06929347664117813,
-0.026641512289643288,
0.08536826074123383,
0.05847133323550224,
0.00544... |
<p>Throw $x$ dice, each of which has $z$ sides, keep the $y$ highest values rolled, and find their sum $s$. In roleplaying games, this is called a "roll and keep dice mechanic" and notated "$x$d$z$k$y$" or perhaps just "$x$k$y$" if the number of sides $z$ is understood. Let (capital) $S$ be the random variable for the ... | g60689 | [
-0.01417483575642109,
-0.01137289684265852,
-0.01431423332542181,
-0.04962944611907005,
-0.0028853132389485836,
-0.06049249321222305,
0.008159782737493515,
-0.035410623997449875,
0.029136579483747482,
-0.05229943245649338,
-0.04640082269906998,
-0.004674913827329874,
0.03572184965014458,
0... |
<p>this is a somewhat random question: is it possible to find clustered standard errors for first difference regressions? (both theoretically and practically in R or Stata).</p>
<p>Thanks!</p> | g60690 | [
0.026394514366984367,
-0.09438890218734741,
-0.013510802760720253,
-0.03305863216519356,
0.04450773075222969,
-0.037043020129203796,
0.010853094048798084,
0.040989506989717484,
-0.056686028838157654,
-0.015953971073031425,
0.005675035994499922,
0.027464520186185837,
0.016471082344651222,
0... |
<p>Are there any differences between binary choice model and classification problem?</p>
<p>For example, binary choice model may use logistic regression, which is also an widely used approach in classification. </p> | g60691 | [
-0.00339991576038301,
0.01867365837097168,
0.051332294940948486,
0.008975580334663391,
0.03644879162311554,
-0.032298341393470764,
-0.011335503309965134,
-0.005331224761903286,
-0.03460615873336792,
0.014800513163208961,
0.05072648450732231,
0.027361202985048294,
0.07406613230705261,
0.020... |
<p>I am working with the following data (see picture)</p>
<p>I am trying to predict future Y axis values from the X values. As you can tell from the picture and as I discovered, the prediction is going to be horrible based on the data alone.</p>
<p>I am now trying to go row by row through the data and classify each p... | g16924 | [
-0.0034238470252603292,
-0.019034283235669136,
-0.015953168272972107,
-0.047537434846162796,
0.002561702160164714,
-0.06588570773601532,
0.05604502931237221,
0.042239826172590256,
-0.037970203906297684,
0.007883679121732712,
0.028011789545416832,
0.06868193298578262,
0.07386171072721481,
0... |
<p>I want to do a study to examine if there is a correlation between nursing students' confidence & satisfaction, and their intuitiveness. I have two instruments, <em>The Student Satisfaction and Self-Confidence in Learning questionnaire</em> is a 13 item instrument which uses a five point scale to measure self con... | g46505 | [
0.012640644796192646,
-0.022351112216711044,
-0.004689972847700119,
-0.053301721811294556,
0.0219141636043787,
0.0036125790793448687,
-0.02866137959063053,
-0.030971642583608627,
-0.016604559496045113,
0.007621662225574255,
0.034345198422670364,
0.04543395712971687,
-0.0015474657993763685,
... |
<p>I have a 10x10 matrix composed of two variables with 10 brands each. One variable is the brand purchased, the other is the brand considered. My matrix shows a crosstabulation between the two. I need an effective way to clearly visualize these data so that proximities suggest similarities between categories and dista... | g16926 | [
-0.006443120539188385,
-0.01732436567544937,
0.004038382787257433,
-0.06475949287414551,
-0.025925301015377045,
-0.08042484521865845,
0.04893402010202408,
-0.0005320640048012137,
-0.037900954484939575,
0.023786159232258797,
0.021811027079820633,
-0.011515562422573566,
0.11311191320419312,
... |
<p>Can someone help me validate my answer to this question:</p>
<p><img src="http://i.stack.imgur.com/CwlLR.png" alt="enter image description here"></p>
<p>My answers come from the first row, where the significances are 0.0002,0.0011, and 0.0005, respectively. Since they are all below 5%, then the conclusion should ... | g60692 | [
0.041247013956308365,
-0.029999272897839546,
-0.009821888990700245,
-0.03849150985479355,
0.07991699129343033,
0.012107029557228088,
0.07318941503763199,
-0.009823502972722054,
-0.007656451314687729,
-0.0030220714397728443,
-0.03752005100250244,
0.01715400256216526,
0.02864254079759121,
0.... |
<p>I am trying to find specific y value of fitted regression model using specific x value.</p>
<p>for example, in the multiple regression model like below,</p>
<blockquote>
<p>y~ aX+bZ+cW +error</p>
</blockquote>
<p><strong>I fitted the model with data</strong> and
I have the result of fitted glm model like </p>
... | g60693 | [
0.05104641616344452,
-0.017501452937722206,
-0.007210817188024521,
0.018892068415880203,
0.011607141233980656,
-0.035335082560777664,
-0.018596434965729713,
0.015220699831843376,
-0.05450522154569626,
-0.011823151260614395,
0.011789954267442226,
0.058731596916913986,
0.047363851219415665,
... |
<p>How do you derive the expression for the $100(1-\alpha)$% bayesian confidence interval when working with the uniform distribution in the interval $[-\theta,\theta]$?</p> | g60694 | [
-0.012727603316307068,
0.011890468187630177,
-0.04230961203575134,
-0.0026258747093379498,
0.030326135456562042,
-0.004904549103230238,
0.04130967706441879,
0.02619084343314171,
0.0000737309965188615,
-0.01737169548869133,
-0.027978738769888878,
0.03151557967066765,
-0.0019685367587953806,
... |
<p>I implemented decision tree according by Russell and Norvig AIMA (in the 3rd edition, p.704).</p>
<h2>Assumption</h2>
<p>The given formula for calculating entropy does not work for the cases when you have all positives examples, or all negative ones. </p>
<p>For binary outcomes:</p>
<p>$$B(q) = -(q * lg_2(q)+(1-... | g46515 | [
0.005803896114230156,
-0.049341849982738495,
0.011845673434436321,
-0.008606203831732273,
0.015467886812984943,
-0.06596634536981583,
-0.006859722547233105,
0.0651208683848381,
-0.041814349591732025,
0.022736698389053345,
-0.007368193473666906,
0.05041515827178955,
0.06646011024713516,
-0.... |
<p>I am preparing for an exam, I've been reading through Likelihood Ratio Test, but don't get it.</p>
<p>Example 8.2.3 (page 376 in "Statistical Inference" Casella and Berg)</p>
<p>Let ${{x}_{1}},...{{x}_{n}}$ be a random sample from an exponential population with pdf
$$f(x|\theta )=\left\{ \begin{array}{*{35}{l}}
... | g16937 | [
0.01990576833486557,
-0.024321824312210083,
-0.020225990563631058,
-0.04111841693520546,
-0.011526690796017647,
0.008500373922288418,
0.021564824506640434,
0.059214044362306595,
-0.026115890592336655,
0.0015698970528319478,
-0.01592346839606762,
-0.0025292974896728992,
0.053163960576057434,
... |
<p>I need to compare sample distributions with theoretical ones, which is typically done with a chi-squared test. The problem is that I have distributions where one or more cells have low values, and consequently the chi-squared test reports very small p-values.
For example, a typical expected and observed frequencies... | g60695 | [
0.041098762303590775,
0.0010987332789227366,
-0.002971184905618429,
-0.004980281926691532,
0.0004701260186266154,
-0.05587710812687874,
0.0007092491141520441,
0.006253016646951437,
-0.025196025148034096,
0.003141233464702964,
0.016383986920118332,
0.05285586416721344,
0.047030750662088394,
... |
<p>I was looking for some information about curvilinear relationships (quadratic function, to be precise) in logistic regression online, and couldn't really find much about it. </p>
<p>I am interested if that could be done, and if so, how can I do it in SPSS? Do I just square the variable that I want to test for a cur... | g60696 | [
0.034326568245887756,
-0.046117790043354034,
0.005601603537797928,
-0.05891066789627075,
0.036951132118701935,
-0.04121296480298042,
-0.04995917156338692,
-0.025438060984015465,
-0.025260571390390396,
-0.028336824849247932,
0.021699227392673492,
0.014870727434754372,
0.07958491891622543,
-... |
<p>In a Wilcoxon signed-ranks statistical significance test, we came across some data that produces a $p$-value of $0.04993$. With a threshold of $p < 0.05$, is this result enough to reject the null hypothesis, or is it safer to say the test was inconclusive, since if we round the p-value to 3 decimal places it beco... | g16939 | [
0.04532759636640549,
0.02752634696662426,
-0.00017461483366787434,
-0.05517138913273811,
0.019908713176846504,
0.009423657320439816,
0.012198504991829395,
0.017931461334228516,
0.027912607416510582,
-0.0305242408066988,
-0.017521612346172333,
0.040531598031520844,
0.012137590907514095,
-0.... |
<p>I have some percentage data derived from the analysis of grain presence and absence in ears of wheat that have undergone two treatments (control and heat stress). For example, data might be like 10%, 15%, 20% for stress and 80%, 85%, 90% for control.</p>
<p>I understand (not least from the link below) that I need t... | g60697 | [
0.062106408178806305,
-0.030773408710956573,
-0.013823711313307285,
-0.09562400728464127,
0.00741403317078948,
-0.05812936648726463,
0.015854259952902794,
-0.011532257311046124,
-0.009187082760035992,
-0.024915378540754318,
-0.01017198245972395,
0.06634468585252762,
0.06706591695547104,
-0... |
<p>I have a dataframe (of prices) as given below</p>
<pre><code>dat <- data.frame(company = rep(c("A", "B", "C", "D", "index"), each = 5),
prices = c(runif(5, 10, 12), runif(5, 108, 112), runif(5, 500, 510),
runif(5, 40, 50), runif(5, 1000, 1020)))
</code></pre>
<p>I need to find the beta
of A, B, C and D w.r.t in... | g16940 | [
0.013048297725617886,
-0.002470920793712139,
-0.016467906534671783,
-0.0770786702632904,
0.06178824603557587,
-0.06921114027500153,
0.07620102167129517,
-0.03729276731610298,
-0.08597353845834732,
-0.032917119562625885,
-0.026324942708015442,
0.07116591930389404,
-0.008160975761711597,
-0.... |
<p>Suppose $X_1,\ldots,X_n$ is a random sample from the density function </p>
<p>$$f(x,\theta)=\displaystyle\frac{1}{2\theta}e^{\displaystyle-\frac{|x|}{\theta}}, \quad -\infty<x<\infty\,\text{.}$$</p>
<p>If $T_1=\sum_{i=1}^{n} a_i X_i\, $ and $T_2=\sum_{i=1}^{n} |X_i|$, how would I calculate $cov(T_1,T_2)$?</... | g60698 | [
-0.025090420618653297,
0.010640214197337627,
-0.02541646547615528,
-0.06023399159312248,
0.0057601528242230415,
-0.04481026902794838,
0.05647827684879303,
-0.016806066036224365,
-0.033941738307476044,
0.035691291093826294,
-0.045361343771219254,
0.00990295223891735,
0.050712913274765015,
0... |
<p>Usually $r$ is transformed into Fisher $z$ to test difference between two $r$ values. But, when a meta-analysis is to be performed, why we should take such a step? Does it correct for measurement error or non-sampling error and why should we assume that $r$ is an imperfect estimate of population correlation? </p> | g16942 | [
0.010864006355404854,
-0.02731674537062645,
-0.013382199220359325,
-0.01331918966025114,
0.03625471889972687,
-0.021100934594869614,
0.03152571991086006,
0.03871474415063858,
-0.007043491583317518,
-0.006665464024990797,
-0.027173709124326706,
0.01417065691202879,
-0.026821250095963478,
0.... |
<p>Dear statistics community,</p>
<p>I seek your help to understand the jungle of concepts about probability theory. I am struggling to form a coherent understanding of terms like <em>probability mass function</em>, <em>probability distribution</em>, <em>probability function</em>, concepts about random variables and t... | g16943 | [
0.02328380011022091,
0.0032720291055738926,
-0.004351284820586443,
0.0009040528093464673,
0.0031594946049153805,
0.026181302964687347,
0.0009514848934486508,
0.0011839148355647922,
0.0035966187715530396,
-0.07746287435293198,
0.005058891139924526,
-0.032058920711278915,
0.058632493019104004,... |
<p>I asked survey respondents about two points in time, and asked participants the degree to which they "agree", a typical Likert-style question. For example, as if I had asked "Before Obama became president, life was good" and a separate question, "After Obama became President, life has been good". Normally, one would... | g46519 | [
0.010781385004520416,
-0.019416568800807,
-0.004904965870082378,
-0.022625397890806198,
-0.011316424235701561,
0.025448910892009735,
0.022242523729801178,
-0.03294253721833229,
-0.003218734869733453,
0.026619339361786842,
0.025941628962755203,
0.008207417093217373,
-0.009870990179479122,
0... |
<p>I have a question concerning the coefficients of VAR models used on multiple imputed data (high missigness in some variables: up to 40%).
In particular I would like to know how the coefficients are related to the explained variance. </p>
<p>I have used vector autoregression on multiple imputed data (m=10) and have ... | g9631 | [
0.03279981389641762,
-0.03942073509097099,
-0.0031860950402915478,
0.005815660115331411,
0.06317412853240967,
-0.021662157028913498,
0.03321338817477226,
0.041359759867191315,
-0.0158248133957386,
-0.0017586910398676991,
-0.08042455464601517,
0.047136370092630386,
-0.015673469752073288,
0.... |
<p>One of the independent variables for my binomial logit regression is age. In order to make age normal, I transform it to square root age by using ladder options. How I can interpret the transformed square root age using odd ratio.</p>
<p>Thank you!</p> | g60699 | [
-0.01630917750298977,
-0.004482946824282408,
-0.015360232442617416,
-0.054660551249980927,
-0.012715487740933895,
-0.020500019192695618,
0.004537095781415701,
0.017789455130696297,
0.01632830686867237,
-0.019872773438692093,
0.0121078472584486,
0.03012142889201641,
0.020162608474493027,
-0... |
<p>Suppose that $X$ and $Y$ are two i.i.d. uniform random variables on the interval $[0,1]$</p>
<p>Let $Z=X/Y$, I am finding the cdf of $Z$, i.e. $ \Pr(Z\leq z) $.</p>
<p>Now, I came up with two ways of doing this. One produces a correct answer consistent with the pdf here: <a href="http://mathworld.wolfram.com/Unif... | g60700 | [
0.05679578334093094,
-0.09872796386480331,
-0.017812905833125114,
-0.030556000769138336,
0.026632022112607956,
0.00412170821800828,
0.04283131659030914,
0.019859587773680687,
-0.04153430834412575,
-0.01710970513522625,
0.0038733852561563253,
0.01587838865816593,
0.016087885946035385,
0.035... |
<p>Let $X_1$ and $X_2$ be real-valued independent random variables with a standard normal distribution. Let $ Y = X_1X_2$. Find the characteristic function of Y.</p>
<p>Attempt:</p>
<p>$\phi_{Y}(t)$ = $\frac{1}{\sqrt{2\pi}}\int_{-\infty}^{\infty} exp(it(x_1x_2))exp(-1/2(x_1x_2)^2)dx_1dx_2$</p>
<p>I know that the sta... | g49593 | [
0.0167899951338768,
0.004168741405010223,
-0.021586310118436813,
-0.03685295581817627,
-0.02691843919456005,
-0.03283359482884407,
0.029586030170321465,
0.009785366244614124,
0.018174659460783005,
0.025177674368023872,
-0.02892620489001274,
0.058534372597932816,
-0.05142712965607643,
-0.00... |
<p>I'm trying to figure out the derivation of the Euclidean update rule for NMF on page 2 of <a href="http://sig.umd.edu/publications/Tjoa_ICASSP2_201003.pdf" rel="nofollow">http://sig.umd.edu/publications/Tjoa_ICASSP2_201003.pdf</a> but can't seem to eke it out. The end result that they get is:</p>
<p>$$
\frac{\parti... | g60701 | [
0.013239123858511448,
-0.015230649150907993,
-0.016522249206900597,
-0.08724820613861084,
0.007626596838235855,
-0.0906963050365448,
-0.003341593546792865,
0.024637611582875252,
-0.0691387876868248,
-0.00005287411477183923,
-0.0109312254935503,
0.0023754057474434376,
0.05180156230926514,
0... |
<p>I have inherited some legacy code designed to solve the following problem - we are given a set of observable binary variables $Y_1, \dots , Y_N$ that we believe are related to a fixed set of input variables $X_1 ,\dots , X_M$ (N.B. high dimension, $M \sim 100$). For a given input we want to predict which event $Y_i... | g60702 | [
0.007009970489889383,
-0.04621228203177452,
0.015217839740216732,
-0.04767722636461258,
0.00771315349265933,
-0.04338674992322922,
-0.014813791029155254,
-0.007529151625931263,
-0.007537506520748138,
-0.05674094706773758,
0.011991877108812332,
0.05310551077127457,
0.04358021914958954,
0.02... |
<p>I would like to compare the nutrient intake of males with that of females. One of the assumptions of the Mann Whitney test U test is that the two variables must not be normally distributed. The nutrient intake of males is normal but not of females. Would this be a problem? Also, the data is on intake of seven nutrie... | g9633 | [
0.030925801023840904,
-0.0001755047996994108,
0.0005475236685015261,
-0.021073171868920326,
-0.032152898609638214,
0.0028855162672698498,
-0.020309489220380783,
-0.03875035420060158,
-0.037952031940221786,
0.0026302326004952192,
0.05796220153570175,
-0.03571875020861626,
-0.00416177557781338... |
<p>what is a good adjusted R square value for any multiple regression model or it depends? If it depends then what are the conditions?</p> | g16950 | [
-0.003169977804645896,
-0.03926503285765648,
0.012114208191633224,
0.011240837164223194,
-0.01118556596338749,
-0.017998240888118744,
0.014389622025191784,
0.05371125042438507,
0.007913481444120407,
-0.023891959339380264,
0.009502485394477844,
0.010040195658802986,
0.008047087118029594,
0.... |
<p>The mean squared error of an estimator $\hat{\theta}$ with respect
to an unknown parameter $\theta$ is defined as
$$
MSE(\hat{\theta})=E[(\hat{\theta}-\theta)^{2}].
$$
It is well known that there is the following bias-variance decomposition:</p>
<p>$$
MSE(\hat{\theta})=Var(\hat{\theta})+\left(Bias(\hat{\theta},\t... | g60703 | [
0.01905510388314724,
-0.06860664486885071,
-0.010236968286335468,
-0.0226360484957695,
0.037022870033979416,
0.013104206882417202,
0.0297443438321352,
0.024351900443434715,
-0.034235887229442596,
0.01356275100260973,
0.009962473064661026,
0.02658872678875923,
0.0708191767334938,
0.00923103... |
<p>I'm developing a tool to conduct expert elicitations of scientists. As answers to questions are speculative, we like experts to help us understand the range of answers they find plausible, to get some idea of uncertainty.</p>
<p>For one type of question, we have them input a lower-bound, upper-bound, 25th percentil... | g16952 | [
-0.024411631748080254,
0.00751279154792428,
-0.007762307766824961,
-0.08029995858669281,
-0.07709463685750961,
-0.05215932056307793,
-0.020430108532309532,
0.004321614280343056,
-0.020924769341945648,
-0.015366138890385628,
0.09905225038528442,
-0.014071638695895672,
0.06155594065785408,
-... |
<p>Beginner user of R here struggling with a repeated measures ANOVA.</p>
<p>I have a dataset that consists of one between subjects factor with 4 levels (coded in a single variable called 'groups'), and one within subjects factor with 4 levels (coded in four separate variables 'DV1', 'DV2', 'DV3', 'DV4'). </p>
<p>I h... | g49523 | [
-0.01081366091966629,
-0.06000084802508354,
-0.015087553299963474,
-0.041918423026800156,
-0.0314265601336956,
-0.046623241156339645,
-0.011521131731569767,
-0.012790407985448837,
-0.02973502315580845,
-0.024951491504907608,
-0.03280908241868019,
0.03809983283281326,
-0.023314688354730606,
... |
<p>Let $X$ be any distribution with defined mean, $\mu$, and standard deviation, $\sigma$. The central limit theorem says that
$$
\sqrt{n}\frac{\bar{X} - \mu}{\sigma}
$$
converges in distribution to a standard normal distribution. If we replace $\sigma$ by the sample standard deviation $S$, is there a theorem stati... | g60704 | [
0.037479326128959656,
0.043606117367744446,
0.003474530763924122,
-0.05519286170601845,
-0.048506397753953934,
-0.02552611008286476,
-0.007942958734929562,
-0.00413782661780715,
-0.026210464537143707,
0.008811806328594685,
-0.012581571005284786,
-0.02171960473060608,
-0.026776138693094254,
... |
<p>I would like to generate data points with given regression coefficients, where some of the variables may be discrete and some continuous, and I am performing both "direct" and "reverse" regressions.</p>
<p>For example, I would like to generate data points consisting of triples $(x,y,z)$ where $x$ is either 0 or 1 a... | g38067 | [
0.015037601813673973,
-0.04989805445075035,
-0.023159487172961235,
-0.011195670813322067,
0.06097397580742836,
-0.07907997816801071,
0.04425381124019623,
0.04904448986053467,
-0.01593833416700363,
-0.04976020008325577,
-0.05018587037920952,
0.04122765362262726,
0.03453143313527107,
-0.0130... |
<p>I performed the Kruskal-Wallis one-way ANOVA by ranks on five groups of data using Dataplot software. The software corrects for ties and uses Conover's procedure to do pairwise multiple comparisons.</p>
<p>The result of the test is $H=5.62$ and $p=.229$ so the results are not significant ($p$ is not less than $.05... | g10 | [
-0.018537012860178947,
-0.02620047517120838,
0.0016331198858097196,
-0.05463104695081711,
-0.016048436984419823,
-0.02096596546471119,
-0.0076764170080423355,
-0.032778020948171616,
-0.05267447233200073,
-0.024639667943120003,
0.0610065758228302,
0.01801346242427826,
-0.0013502693036571145,
... |
<p>I have binomial frequency data for an allele associated with populations living in mountainous. These mountains run north to south where sites are nearly fixed for this allele and lowland sites to the east that lack the allele. At the south end of the mountains is a hybrid zone. Despite the mountains continuing sout... | g60705 | [
0.013641715981066227,
-0.012081461027264595,
0.004931093659251928,
0.06790872663259506,
-0.025857066735625267,
0.01091049239039421,
0.05296236649155617,
0.041869405657052994,
-0.020452039316296577,
-0.035330116748809814,
0.042448680847883224,
0.01463747676461935,
0.03712015226483345,
-0.00... |
<p>My question is like this.</p>
<p>The regression specification is: </p>
<p>$y=\delta_{1}D_{1}+\delta_{2}D_{2}+\delta_{3}D_{3}+\beta_{1}x_{1}+\beta_{2}x_{2}+\beta_{3}x_{3}+\epsilon$ </p>
<p>where $D_{i}$ denotes dummy for each one of three categories, $x_{i}$ interaction between $D_{i}$ and independent variable $x... | g60706 | [
0.0008738351170904934,
0.00764025654643774,
0.007270365953445435,
-0.03246429190039635,
-0.0020821320358663797,
-0.018392065539956093,
0.060223475098609924,
0.01602591760456562,
-0.04707494378089905,
-0.007085955701768398,
-0.001478748396039009,
0.04783449321985245,
-0.02478904463350773,
-... |
<p>Consider a multivariate random variable $x$ with density function $P_x(\theta)$ for a scalar parameter $\theta$. Assume the Fisher information $J_x(\theta)$ is known.</p>
<p>Now, for a transformation (deterministic mapping) $y=F(x)$ can you express $J_y(\theta)$ in terms of $J_x(\theta)$ and $F$?</p> | g27981 | [
0.0014956959057599306,
-0.011214633472263813,
-0.015962237492203712,
-0.0628516674041748,
0.02607225440442562,
-0.08549617230892181,
-0.027451803907752037,
-0.031186256557703018,
-0.04584294557571411,
0.009152534417808056,
-0.06555602699518204,
0.044799141585826874,
0.044701166450977325,
0... |
<p>The regression specification is:</p>
<p>$y=\delta_{1}D_{1}+\delta_{2}D_{2}+\delta_{3}D_{3}+\beta_{1}D_{1} \cdot X+ \beta_{2}D_{2} \cdot X+\beta_{3}D_{3} \cdot X+\epsilon$</p>
<p>where $D_{i}$ denotes dummy for each one of three groups, $D_{i} \cdot X$ interaction between $D_{i}$ and independent variable $X$.</p>
... | g44124 | [
-0.0285224299877882,
-0.009018000215291977,
-0.006513361819088459,
-0.03008434921503067,
0.014117702841758728,
-0.010259893722832203,
0.04402429237961769,
-0.005184891168028116,
-0.038047805428504944,
-0.016347438097000122,
-0.0211191289126873,
0.04404498264193535,
-0.020255940034985542,
0... |
<p>My model is predicting a binomial dependent variable with a rich feature space of 20,000 independent variables. I am using the penalized logistic regression from the glmnet package, which works for the kind of dataset I have. I am using 10-fold cross-validation and the cross validation error is just 2.4%. I was told... | g60707 | [
0.03958454355597496,
0.009957651607692242,
-0.006081530824303627,
-0.01599109172821045,
0.015005572699010372,
0.012520779855549335,
0.019107822328805923,
-0.016029061749577522,
-0.06030545011162758,
-0.00924866646528244,
0.029749786481261253,
-0.0005370904691517353,
0.00490536168217659,
-0... |
<p>I am working on a binary classification problem with relatively few instances (e.g. ~30 instances out of which ~7 are positives).</p>
<p>I have noticed that when using 2-fold the average classification performance of the best performing model is better than the best performing model with 5-fold. </p>
<p>In fact, <... | g60708 | [
0.04777275398373604,
-0.0032961678225547075,
0.005312945228070021,
-0.02136388048529625,
0.03878270834684372,
-0.021499572321772575,
0.04531509801745415,
-0.004279525019228458,
-0.022754965350031853,
-0.0454244427382946,
0.0405496247112751,
0.023973314091563225,
0.04967300966382027,
0.0031... |
<p>this has been vexing me for a while and I can't seem to solidify an answer beyond vague thoughts about Poisson distributions. I think this is a simple problem and I'm missing something obvious. Any thoughts appreciated, particularly with R snippets :) </p>
<p>Chris</p>
<p>Experiment: 2 replicate assays from each o... | g34059 | [
0.005448109470307827,
-0.012725459411740303,
-0.00943897943943739,
-0.04069855064153671,
-0.0024082527961581945,
-0.008490522392094135,
0.01811041124165058,
0.05909302830696106,
0.009222874417901039,
-0.01613403856754303,
-0.020632155239582062,
-0.002691060770303011,
0.013401278294622898,
... |
<p>I'm doing some work with random forests in R using the <code>randomForest</code> package, and I've run into something that seems odd to me. Even when the data is completely random, the AUC is never less than 0.5. For example, when I run the following:</p>
<pre><code>library(randomForest)
df.sanity <- data.frame(... | g16960 | [
0.02114088088274002,
-0.0413883775472641,
0.007775869220495224,
-0.07288669049739838,
0.03636461868882179,
-0.049085404723882675,
0.03262579068541527,
0.03649483248591423,
-0.022380298003554344,
-0.05330565199255943,
0.013481305912137032,
0.014565777033567429,
0.02003413811326027,
-0.00300... |
<p>Consider an outcome variable that has four clear, ordered categories to it. This seems like a good use of ordinal logistic regression to estimate Odds Ratios for the effect of covariates on moving a subject one "step" up the ladder.</p>
<p>But the subjects are particularly evenly spread throughout the categories, s... | g22002 | [
-0.01509588398039341,
-0.00967217143625021,
-0.01634129136800766,
-0.08167538791894913,
-0.03159104660153389,
-0.04893103986978531,
0.014709576964378357,
-0.0041354927234351635,
-0.036489129066467285,
-0.0002228682569693774,
0.024548189714550972,
0.009810298681259155,
0.03896450251340866,
... |
<p>I'm learning stratified random sampling and I'm having hard time to solve this problem. consider the following population of six units:</p>
<pre><code>x1=1, x2=2, x3=2, x4=4 x5=4 x6=5
</code></pre>
<p>Suppose units 2 3 4 and 5 are in one stratum and units 1 and 6 are in a second stratum. Take a simple random sampl... | g60709 | [
0.03081265091896057,
-0.03817523270845413,
0.0035512722097337246,
-0.04776241257786751,
0.020025519654154778,
0.014707888476550579,
0.007426501251757145,
-0.01139497384428978,
-0.01203651912510395,
0.021776963025331497,
-0.0302741639316082,
-0.03433354198932648,
-0.0159158892929554,
0.0070... |
<p>I'm currently working as a teaching assistant at my University, in an introductory statistics course (for medical students).</p>
<p>Offline, there are many books available with information to aid the teacher. However what I am interested to know is if you might direct me to any (good) <strong>resources that provid... | g16962 | [
0.04859528690576553,
-0.008574771694839,
-0.026599200442433357,
-0.043369341641664505,
-0.04548810422420502,
0.031109921634197235,
0.02686203643679619,
0.030138030648231506,
-0.0017792565049603581,
-0.015591675415635109,
0.019405357539653778,
-0.018131092190742493,
0.055829115211963654,
0.... |
<p>This may be too much of a general question but I hope I can find help here. I am starting a RA job in my university and my topic will be related to Internet Traffic Analysis. I am fairly new to the world of analysis but I guess in the world of research this is what I have to do a lot of.</p>
<p>I've been through a ... | g49784 | [
0.01918725296854973,
0.019426513463258743,
-0.010160247795283794,
-0.06637445837259293,
0.01634293980896473,
-0.03725356236100197,
0.0678376704454422,
0.026932114735245705,
-0.024511639028787613,
-0.010524437762796879,
0.035991013050079346,
-0.03046496771275997,
0.047240108251571655,
-0.01... |
<p>I wasn't able to find one on Google, and was wondering if one exists...</p> | g60710 | [
-0.008870462886989117,
0.03208591789007187,
0.007586311083287001,
-0.07001844793558121,
-0.014420508407056332,
-0.03238028660416603,
-0.06990943104028702,
0.03421110659837723,
-0.048540256917476654,
-0.006714375223964453,
-0.012781647965312004,
0.03891466185450554,
-0.02823629602789879,
-0... |
<p>Let $X \sim \chi^2_k$ be a chi-squared distributed random variable with $k$ degrees of freedom. What are the sharpest known bounds for the following probabilities</p>
<p>$$
\mathbb{P}[X > t] \leq 1 - \delta_1(t, k)
$$
</p>
<p>and</p>
<p>$$
\mathbb{P}[X < z] \leq 1 - \delta_2(z, k)
$$
</p>
<p>where $\de... | g16965 | [
0.013222559355199337,
0.009416368789970875,
-0.022611113265156746,
0.0224598441272974,
0.04489382728934288,
-0.030686255544424057,
0.02448609098792076,
-0.01660630851984024,
-0.01147384662181139,
0.02787625789642334,
-0.03561835736036301,
0.03427257761359215,
0.00899579469114542,
0.0220341... |
<p>I have two LME models with the same interaction, one containing both main effects and one containing only one main effect, say :</p>
<p>$$ H\_CE = Season + Crownlevel + Season:Crownlevel , random = 1|CollectorID $$
and
$$ H\_CE = Season + Season:Crownlevel , random = 1|CollectorID $$</p>
<p>There are 4 levels of e... | g60711 | [
0.0075995041988790035,
-0.04716915264725685,
-0.00797407515347004,
-0.006186753045767546,
0.054297152906656265,
0.01346155907958746,
0.06310977786779404,
0.009742527268826962,
-0.053389858454465866,
0.01721043698489666,
-0.03692879527807236,
0.04685836285352707,
0.049187298864126205,
-0.02... |
<p>So if I fit data to a function you can almost always decrease $\chi_{\nu}^2$ by adding more free parameters. However, this becomes ridiculous if you are fitting a 100-order polynomial to a straight line data set. There is obviously some point where you stop adding parameters!</p>
<p>Is there any quantitative means ... | g60712 | [
0.0006529169622808695,
0.04221981391310692,
-0.009080029092729092,
-0.049131568521261215,
0.047732893377542496,
-0.05071702226996422,
-0.013950587250292301,
-0.016574839130043983,
-0.07349801063537598,
-0.0020684748888015747,
-0.05456876754760742,
0.005707683973014355,
0.02161213383078575,
... |
<p>I have 2 categorical variables that I want to add into one single variable entitled <code>UnhealthyConsumption</code>: </p>
<blockquote>
<p>FastFoodConsumption (1=never, 2=once a month, 3= 1-2 days/week, 4= 3-4/week, 5= 4-5/week, 6= everyday),</p>
<p>SnacksConsumption (1=never, 2=once a month, 3= less than o... | g60713 | [
-0.01223243959248066,
0.04497349262237549,
0.022377990186214447,
-0.03085014410316944,
0.018646467477083206,
-0.09883806109428406,
-0.02178201824426651,
0.02400250919163227,
-0.05412445217370987,
0.014268261380493641,
0.045974817126989365,
-0.012960581108927727,
0.05734928324818611,
0.1090... |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.