question stringlengths 37 38.8k | group_id stringlengths 2 6 | sentence_embeddings listlengths 768 768 |
|---|---|---|
<p>I have a table that contains items. Each day its possible that an incident can occur to some items but equally no incident may happen. I wish to see if its possible to create a prediction for the next day based on the information below</p>
<pre><code>**Date Item 1 Incident Location**
20130701 40 ... | g58648 | [
0.028793692588806152,
-0.04880879074335098,
-0.008204937912523746,
-0.05763018876314163,
-0.02735934406518936,
-0.03603744134306908,
0.03296060487627983,
-0.012476233765482903,
-0.051377855241298676,
-0.03846113756299019,
0.059631556272506714,
0.003934130538254976,
0.06655360758304596,
-0.... |
<p>How do i compare (p-value) regression slopes for 2 groups fitted with the same model but with different sample size?</p>
<p>Model: y=cov_1*X1+...+cov_5*X5+slope_group_1*X6 and similarly for group 2. I followed <a href="http://stats.stackexchange.com/questions/13112/what-is-the-correct-way-to-test-for-significant-di... | g58649 | [
0.012422206811606884,
-0.037945669144392014,
-0.006658683065325022,
0.019645562395453453,
0.06457836180925369,
-0.03314878046512604,
0.02880665846168995,
-0.01285618543624878,
-0.06304851174354553,
-0.014569699764251709,
0.01004563458263874,
0.026915550231933594,
0.0398079939186573,
0.0130... |
<p>I've just been introduced (vaguely) to <a href="https://en.wikipedia.org/wiki/Brownian_covariance">brownian/distance covariance</a>. It seems particularly useful in many non-linear situations, when testing for dependence. But it doesn't seem to be used very often, even though cov/corr is often used for non-linear/ch... | g13801 | [
-0.015658756718039513,
0.007978483103215694,
0.010710571892559528,
-0.008891844190657139,
-0.022430267184972763,
0.01576760970056057,
0.06755448132753372,
-0.006717722862958908,
-0.0320093035697937,
0.0004320766020100564,
0.05624379962682724,
-0.02726912871003151,
0.03912730515003204,
0.02... |
<p>I was trying to fit logistic regression with a binary response variable and a continuous predictor variable. But when I plotted the fitted probabilities vs the predictor, I got an almost straight line instead of the expected sigmoid curve.</p>
<p>What can be the reason for this?</p> | g58650 | [
0.0604223757982254,
-0.042492084205150604,
0.006462160497903824,
-0.010104105807840824,
0.009765055030584335,
-0.006708265747874975,
0.018411921337246895,
0.0393543541431427,
-0.053162407130002975,
-0.07962112128734589,
0.05253944918513298,
0.00791383720934391,
0.025409391149878502,
0.0375... |
<p>I have a state-space model (actually belonging to a Kalman Filter) as in the given graphical model:
<img src="http://i.stack.imgur.com/bJgXb.png" alt="Kalman"></p>
<p>This is a typical 1 dimensional Linear Dynamic System model. The variances $Q$ and $R$ have Inverse Gamma priors and the coefficient $A$ has a Gaussi... | g58651 | [
-0.008263855241239071,
-0.05209868401288986,
-0.01696024276316166,
-0.06533791124820709,
-0.03412681445479393,
0.009524253197014332,
0.015182157047092915,
-0.037109680473804474,
-0.02050665020942688,
-0.03320774435997009,
0.008698123507201672,
0.024799661710858345,
0.002119395649060607,
0.... |
<p>I have implemented the discriminant function and was able to classify the 2D patterns (via Python), but I have troubles thinking about an approach to plot the decision boundaries. Hope anyone has an idea how I can achieve this.</p>
<p>More specifically, I am wondering if I need to derive the separate decision bound... | g13803 | [
-0.009200245141983032,
-0.04149250686168671,
0.010266236960887909,
-0.003637425834313035,
0.005386123899370432,
-0.0218783151358366,
0.046311620622873306,
-0.011892021633684635,
-0.03792737424373627,
-0.03715686872601509,
-0.00279049389064312,
0.08631366491317749,
0.11791903525590897,
0.00... |
<p>How does the expected value of a continuous random variable relate to arithmetic mean, median, etc. in a non-normal distribution (eg. skew-normal)? I'm interested in any common/interesting distributions (eg. log-normal, simple bi/multimodal distributions, anything else weird and wonderful).</p>
<p>I'm looking most... | g42754 | [
-0.035533297806978226,
0.02213534712791443,
-0.028078636154532433,
-0.016238253563642502,
-0.04414399340748787,
-0.0237907562404871,
-0.0020154849626123905,
0.002045994158834219,
-0.008900405839085579,
-0.00653638131916523,
-0.01163675356656313,
-0.010738284327089787,
0.025092482566833496,
... |
<p>I have 10 samples with sample size $N=30$ in each case.</p>
<p>Null Hypothesis = (population mean) $\mu\le14$</p>
<p>Alternative Hypothesis= (population mean) $\mu>14$</p>
<p>confidence level = 0.95</p>
<p>there is an equation for hypothesis testing $Z$
$$
Z=\frac{(\bar{x}-\mu)}{\frac{SD}{\sqrt{N}}}
$$
can ... | g58652 | [
0.020438363775610924,
0.0033151316456496716,
-0.004443268291652203,
-0.042372047901153564,
0.044274672865867615,
-0.028507959097623825,
0.02547452412545681,
0.04497572407126427,
-0.01984219066798687,
-0.004538627341389656,
0.014690021052956581,
0.023083865642547607,
-0.005619837902486324,
... |
<p>I'm working with panel data and want to fit a model of the form:</p>
<p>$y_{ij} = \alpha_{i} + \beta_{1i} x_{1ij} + \beta_{2i} x_{2ij} + \beta_{3} treatment_{ij} + \epsilon_{ij}$ </p>
<p>The data consist of (unbalanced) time series for a number of individuals, each of which received the treatment at a different ti... | g58653 | [
-0.0019376680720597506,
-0.06330549716949463,
-0.006744030397385359,
-0.07329303026199341,
0.00042509628110565245,
-0.031452007591724396,
0.04073960706591606,
-0.02437800168991089,
-0.04984322190284729,
-0.00793757289648056,
-0.02490365505218506,
0.010101319290697575,
-0.014414782635867596,
... |
<p>I am calculating two different $p$ values for the McNemar test and what I believe is the corresponding <em>exact</em> test, even for combined counts larger than 25.</p>
<p>Take, for example the contingency table</p>
<pre><code> Posttest
Pretest Outcome A Outcome B
Outcome A xx ... | g5334 | [
0.010479019023478031,
-0.008665470406413078,
-0.009550121612846851,
0.006282508373260498,
0.03588532283902168,
-0.037408407777547836,
0.066249318420887,
0.025678882375359535,
-0.05166732892394066,
0.007034264039248228,
-0.02931847609579563,
-0.00186437857337296,
0.02598985843360424,
-0.023... |
<p>What is the time and space(memory) complexity of DBNs? given d:number of dimensions(attributes), n:number of records, and l:number of hidden layers.</p> | g58654 | [
0.01849934458732605,
0.09345971792936325,
-0.010007168166339397,
-0.051559560000896454,
-0.04462461173534393,
-0.03961494565010071,
0.06653805077075958,
-0.00648074084892869,
-0.012059721164405346,
-0.021472103893756866,
-0.06608755886554718,
-0.0023963938001543283,
0.018178394064307213,
-... |
<p>I've found a discrepancy between the output of the fitted() function and adding the residuals to the original data set. Is the fitted() function not doing what I think it should be doing?</p> | g13809 | [
0.04387704282999039,
-0.07248089462518692,
-0.011605815030634403,
-0.044254329055547714,
-0.04163818433880806,
0.017724953591823578,
0.006328140385448933,
-0.0003909551305696368,
-0.05977323278784752,
-0.017652584239840508,
-0.018231047317385674,
0.054116491228342056,
-0.006494033616036177,
... |
<p>Is AR(1) process such as
$y_t=\rho y_{t-1}+\varepsilon_t$ a Markov process? </p>
<p>If it is, then VAR(1) is the vector version of Markov process?</p> | g58655 | [
0.035559140145778656,
-0.057630568742752075,
-0.004344957415014505,
0.04706966131925583,
0.00824120081961155,
-0.05597952753305435,
0.04471743479371071,
0.011925444938242435,
0.003775298595428467,
0.035157956182956696,
-0.025941800326108932,
0.052415356040000916,
0.025722447782754898,
0.01... |
<p>I am struggling to find a solution on finding the distribution of following random variable:</p>
<p>$$Y = Z \cdot |X|$$</p>
<p>here, $Z$ is a random variable takes 1 or -1 with equal probability, and $X$ is a standard normal variate, and $|\cdot|$ denotes absolute value.</p>
<p>Can somebody help me with some poi... | g58656 | [
0.04966852441430092,
0.007138323038816452,
-0.025330450385808945,
-0.03416056931018829,
-0.0075112199410796165,
-0.027475208044052124,
0.02402743324637413,
-0.010141680017113686,
0.01257309876382351,
0.00895098689943552,
0.00009690123988548294,
0.04461703822016716,
0.013120909221470356,
0.... |
<p>I was reading this paper <a href="http://www.ist.temple.edu/~vucetic/documents/wang11kdd.pdf" rel="nofollow">http://www.ist.temple.edu/~vucetic/documents/wang11kdd.pdf</a> related to adaptive multi-hyperplane machine for non linear classification</p>
<p>In that paper, they have mentioned about multiclass SVM, with ... | g5352 | [
0.02786833979189396,
-0.020921876654028893,
0.005972851067781448,
0.04586419090628624,
-0.0006268751458264887,
-0.04621893912553787,
0.014960449188947678,
-0.005295217037200928,
-0.030508525669574738,
-0.0026680997107177973,
-0.05350612848997116,
0.026458755135536194,
0.04920564219355583,
... |
<p>I want to draw a QQ plot for Negative Binomial distribution to see if the Generalized linear model fit well or not. But since there is no normality assumption exist in my model, normal QQ plot will not be suitable in this case. What kind of plot should I do? And how can I do it in R?</p>
<p>I can not simply use qqp... | g58657 | [
0.02022746205329895,
-0.03137403726577759,
0.01074035745114088,
-0.013650156557559967,
-0.04777047038078308,
0.035647619515657425,
0.0011339295888319612,
-0.021658392623066902,
-0.0508534200489521,
-0.03633161634206772,
0.018262561410665512,
-0.006941856816411018,
0.00877321045845747,
-0.0... |
<p>If P(A|B) = 95%, then is P(B'|A') also 95%?</p>
<p>The subject is hypothesis testing. If the null hypothesis is true and there is a 95% probability that the data should pass the test, then does failing the test imply the null hypothesis is wrong with 95% chance?</p> | g37819 | [
0.0598902627825737,
-0.006683687213808298,
0.015320324338972569,
0.01766819693148136,
-0.006909178104251623,
0.02212381549179554,
0.00339312176220119,
-0.037807647138834,
-0.01571705937385559,
-0.027169929817318916,
0.05046126991510391,
0.010428217239677906,
-0.003739443141967058,
-0.01514... |
<p>I have 4 levels for a single factor, which is called "Compliance".</p>
<p>Compliance has an ordinal scale (0, 1, 2, 3) and it is computed as the number of rules a team complies with.</p>
<p>My hypothesis is the following: "the more you comply, the more effective you are". Effectiveness is a real positive number.</... | g58658 | [
-0.033675599843263626,
-0.008024425245821476,
-0.005615509580820799,
-0.03170926868915558,
0.01017592940479517,
-0.03312583267688751,
0.04642800986766815,
0.023825230076909065,
-0.02119372971355915,
0.02470492385327816,
-0.009584910236299038,
0.013050234876573086,
0.028718920424580574,
0.0... |
<p>I am trying to select features from paired samples and was wondering if there are methods out there that adapt random Forest or other machine learning algorithms to paired samples i.e. if randomForest was a machine learning analog to a standard FDR-corrected ANOVA approach, what would be the machine learning analog ... | g43574 | [
-0.00982348807156086,
-0.09121042490005493,
0.03112839162349701,
-0.07306335121393204,
-0.04288150742650032,
-0.03564789518713951,
-0.022282907739281654,
0.013697333633899689,
-0.013175240717828274,
0.012948206625878811,
0.032533030956983566,
0.009237593971192837,
0.0598645955324173,
0.056... |
<p>When performing hierarchical clustering, one can use many metrics to measure the distance between clusters. Two such metrics imply calculation of the centroids and means of data points in the clusters.</p>
<p>What is the difference between the mean and the centroid? Aren't these the same point in cluster?</p> | g58659 | [
0.03777885064482689,
0.008152117021381855,
-0.031501855701208115,
0.016584360972046852,
0.057337917387485504,
-0.008773008361458778,
-0.0027287716511636972,
0.03786561265587807,
-0.06253409385681152,
-0.03638533502817154,
-0.03388950228691101,
0.03504346311092377,
0.03635473921895027,
-0.0... |
<p>Can someone generally explain when the area to the right or area to the left is sufficient in solving a statistical problem (using z, t, or chi)? For example, in a chi-squared problem, if we're looking at a table of p-values we are generally interested in the area to the right. Why is this? What is the area to th... | g38583 | [
0.005034798756241798,
0.07782812416553497,
-0.003238172270357609,
-0.06625857204198837,
0.024942820891737938,
-0.029789211228489876,
0.060618992894887924,
0.05066667124629021,
-0.05231039226055145,
0.004844588227570057,
0.007890996523201466,
0.0006314076599664986,
0.061402928084135056,
0.0... |
<p>I have a response variable measured at three time points per individual (week 0, 18, and 36). I am interested in differences in the change of the response over the 36 weeks within some categorical variable X.</p>
<p>I see two ways of modeling this.</p>
<ol>
<li><p>One way ANOVA with response = <code>week_36_score... | g58660 | [
-0.009875797666609287,
-0.0032244990579783916,
-0.025247719138860703,
-0.0655708909034729,
-0.006637850776314735,
-0.013960085809230804,
0.014994107186794281,
-0.011317984201014042,
-0.002955247415229678,
0.016899824142456055,
-0.01428782008588314,
0.022722259163856506,
0.036083001643419266,... |
<p>I ran a small pilot study and computed both a p-value and Cohen's d. Now how do I compute the number of samples needed for the full study if I want a given power (e.g. 95%).</p>
<p>I hoped I could use <a href="http://en.wikipedia.org/wiki/Sample_size_determination#By_tables" rel="nofollow">this table</a>, but I can... | g58661 | [
-0.008572524413466454,
0.030987324193120003,
-0.008125842548906803,
-0.02449052408337593,
-0.031916916370391846,
-0.09970027953386307,
-0.02315111830830574,
0.05668199434876442,
-0.026431072503328323,
-0.035571325570344925,
0.021129194647073746,
-0.01617799513041973,
0.015209219418466091,
... |
<p>I've been working on a bootstrapping problem that's left me a little confused and wondering whether I'm doing things correctly.</p>
<p>We have around 200 samples from a population of about 3,400, we want to bootstrap a value to estimate the total value for the 3,400 cases. Myself and a colleague both took slightly ... | g58662 | [
-0.0004080600629094988,
-0.007825617678463459,
0.019782589748501778,
0.013811211101710796,
-0.02298186533153057,
-0.013446493074297905,
0.039779167622327805,
0.035728465765714645,
-0.05862966552376747,
-0.011270981281995773,
-0.021539393812417984,
-0.011135409586131573,
0.0463370680809021,
... |
<p>I am attempting to use the kernel PCA features in <code>kernlab</code> but am having trouble understanding the output. In particular, it's unclear what scale the results are in when I try to project the original data unto the resulting eigenvectors. Here is an example:</p>
<pre><code>require(kernlab)
x = data.fram... | g39376 | [
0.012622236274182796,
0.0031303807627409697,
0.027680236846208572,
-0.07758842408657074,
-0.0026388491969555616,
-0.028584251180291176,
0.03038131445646286,
-0.00898119155317545,
-0.04627492278814316,
-0.02702140249311924,
0.015238525345921516,
0.02070830948650837,
-0.003864460624754429,
0... |
<p>For a 2 by 2 contingency table, some said <a href="http://en.wikipedia.org/wiki/Fisher%27s_exact_test" rel="nofollow">Fisher's exact test</a> uses the count $X_{1,1}$ in the (1,1) cell in the table as the test statistic, and under null hypothesis, $X_{1,1}$ will have a hypergeometric distribution.</p>
<p>Some said ... | g39390 | [
0.026945754885673523,
-0.004386740271002054,
-0.014091371558606625,
0.0023086389992386103,
0.03506820648908615,
-0.06653109192848206,
0.004546517506241798,
0.041782964020967484,
-0.062445662915706635,
-0.02130206674337387,
-0.008995448239147663,
0.025480540469288826,
0.003991664852946997,
... |
<p>I'd like to ask the SO community for some help in regard to the interpretation of a structural equation model with three groups, featuring a categorical outcome. I have found a lot of sources treating multi-group CFA with categorical factor indicators, but nothing accessible for models with continuous predictors but... | g58663 | [
-0.04636131972074509,
0.005142043810337782,
-0.012051932513713837,
-0.040814269334077835,
0.03852903097867966,
0.009090063162147999,
0.018652690574526787,
0.06488574296236038,
-0.011194110848009586,
-0.0014645595801994205,
-0.03432892635464668,
-0.01929076574742794,
0.012069866992533207,
-... |
<p>I am really new with R and time series. But, I have understood most concept. Part where I am (very) confused is the <code>xreg=</code> argument in <code>arima()</code> from <a href="http://cran.r-project.org/web/packages/tseries/index.html" rel="nofollow">tseries</a> package and <a href="http://cran.r-project.org/we... | g58664 | [
0.030096452683210373,
0.010393981821835041,
-0.016481006518006325,
-0.0024809788446873426,
-0.022018728777766228,
0.004747041501104832,
0.023240406066179276,
0.015652261674404144,
-0.0296730175614357,
0.022998707368969917,
0.019492801278829575,
0.043185699731111526,
0.052685339003801346,
0... |
<p>I am developing a neuroscience-inspired training algorithm for feed-forward neural networks. The natural benchmark for comparison is backpropagation. So I need to know to know what sort of classification problems backpropagation (and thus feed-forward NNs) is most suited for. Also, since I ultimately want to move b... | g42780 | [
0.052217766642570496,
0.017286410555243492,
0.026575252413749695,
-0.03946813941001892,
0.008991401642560959,
-0.07674188911914825,
0.03148142620921135,
0.026514578610658646,
-0.01607358828186989,
0.008084191009402275,
-0.0041473000310361385,
0.028570076450705528,
-0.004601760301738977,
0.... |
<p>Say, I have a normal distribution $ X \sim N(\mu, \sigma)$, where $\mu$ unknown and $\sigma^2$ known</p>
<p>Then, $-E[2/\sigma]=2/\sigma$ or $-2/\sigma$</p>
<p>This is in reference to the Fisher Information where you have $-E(\cdot)$ of something.</p>
<p>Edit:<br>
I was taking expectation of Fisher Information.
... | g58665 | [
-0.008979490958154202,
0.011045916005969048,
-0.03372841328382492,
-0.023137206211686134,
0.049911726266145706,
-0.02372494898736477,
0.019837377592921257,
0.00726018100976944,
-0.04130520671606064,
-0.03398030251264572,
-0.03579993173480034,
0.09632398188114166,
0.035508353263139725,
0.01... |
<p>What are some ways to prepare/pre-process time series data to use the series data as a predictor(s) in a predictive model (classification or regression)? Specifically, what are the methods to be considered in order to </p>
<ul>
<li>Get the most predicatively useful signal from the data?</li>
<li>Reduce the dimensio... | g13828 | [
-0.00639538886025548,
-0.004030848853290081,
0.010548337362706661,
-0.03536495938897133,
-0.025570455938577652,
-0.03740081936120987,
0.06303884834051132,
0.022891104221343994,
-0.010376377031207085,
-0.05198394134640694,
0.009353955276310444,
0.03233451023697853,
0.09556488692760468,
0.00... |
<p>I am analysing data from a small study. There are two treatment groups and for each, one notes success and failures. For one of the groups, the number of successes is 0. I did an exact significance test, but reviewers of the paper want a confidence interval for the relative risk - in other words, a confidence interv... | g58666 | [
0.0004144884296692908,
-0.03802531957626343,
-0.021905921399593353,
0.0019368326757103205,
-0.009910348802804947,
0.034208446741104126,
0.0071360222063958645,
0.016782889142632484,
-0.035163067281246185,
-0.03566437214612961,
0.06766419112682343,
0.04022617265582085,
0.04762101545929909,
-... |
<p>I have 114 vectors with 6 boolean attributes. I saw that might be several distinct clusters in a simple visualization. K-means clustering on the transformed vectors (true = 1, false = 0) results in roughly the clusters that I had seen in the visualization.</p>
<p>However, I am not sure what the most appropriate clu... | g58667 | [
0.037173546850681305,
0.0059891692362725735,
-0.005801625084131956,
-0.036688465625047684,
0.015143039636313915,
-0.056132722645998,
0.013728500343859196,
0.011173167265951633,
-0.003097893437370658,
-0.009369106031954288,
0.05883193761110306,
0.04447789117693901,
0.07021445035934448,
-0.0... |
<p>I'm simulating data from a logistic regression model:</p>
<pre><code>log(p/1-p)= 0 + X
</code></pre>
<p>where $X \sim N(0,\sigma^2)$. After I simulate the data, I fit a logistic regression model to the data and compare the fitted regression coefficients to the actual regression coefficients. </p>
<p>I've noticed ... | g13835 | [
0.023976502940058708,
-0.016579758375883102,
-0.015241064131259918,
-0.013308951631188393,
0.0667148232460022,
0.0024667007382959127,
0.04018837586045265,
0.012858765199780464,
-0.06934331357479095,
-0.01785922423005104,
-0.051466088742017746,
0.036543115973472595,
-0.008330096490681171,
-... |
<p>Based on <a href="http://sas-and-r.blogspot.com/2010/03/example-730-simulate-censored-survival.html" rel="nofollow">this guide</a> to simulating survival times in SAS and R, I used the following code to generate two survival functions:</p>
<pre><code>data simulation;
call streaminit(321);
beta_death = 0.916... | g58668 | [
0.018370049074292183,
-0.05308440700173378,
0.0005637845606543124,
-0.045616257935762405,
0.03606952354311943,
0.027478883042931557,
-0.017761237919330597,
0.0040954723954200745,
-0.06865179538726807,
-0.01772858388721943,
-0.01898263581097126,
0.04828859493136406,
0.05272935330867767,
0.0... |
<p>I need to use the output from certain tests like Factor Analysis to compute additional variable like socioeconomic status. </p> | g13836 | [
-0.002175897127017379,
-0.023440249264240265,
-0.003929602913558483,
-0.034642696380615234,
-0.024624675512313843,
-0.028739066794514656,
0.024358274415135384,
-0.01628013886511326,
0.003712099278345704,
-0.00037486033397726715,
0.007893352769315243,
0.05442013591527939,
-0.01117521431297063... |
<p>In the proof of Theorem 2.2 from the book by <a href="http://www.szit.bme.hu/~gyorfi/pbook.pdf" rel="nofollow" title="A Probabilistic Theory of Pattern Recognition">Devroye et al.</a>, I don't understand why $g(x) \ne g^*(x)$ implies $|\eta(x) - \tilde\eta(x)| \geq |\eta(x) - \dfrac{1}{2}|$.</p>
<p>Note that $\eta(... | g13838 | [
0.02865210548043251,
-0.012691806070506573,
-0.01630689948797226,
-0.025306688621640205,
0.06806201487779617,
-0.012477150186896324,
0.0767923891544342,
-0.014628475531935692,
-0.06293240934610367,
-0.054725565016269684,
0.0008931424818001688,
0.0555407777428627,
0.08917592465877533,
0.014... |
<p>There is a huge literature on time series analysis. My data does not seem to fit into the standard model in that it consists of event times, that is the times at which an event occurs. What is a good way to measure the correlation between two sequences of event times? Is there any literature on analyzing event tim... | g58669 | [
0.05462375655770302,
-0.0026836139149963856,
0.03756847605109215,
-0.031034935265779495,
0.04635096341371536,
-0.021638743579387665,
0.029514865949749947,
0.05141274258494377,
-0.02759207785129547,
0.021819086745381355,
-0.025562016293406487,
-0.0006690744194202125,
0.0006191867869347334,
... |
<p>My understanding of the bootstrap approach is based on Wasserman's framework (almost verbatim):</p>
<blockquote>
<p>Let $T_n = g(X_1, ..., X_n)$ be a statistic ($X_i$ is the iid sample
drawn from distribution $F$). Suppose we want to estimate $V_F(T_n)$ - the
variance of $T_n$ given $F$. </p>
<p>The boot... | g13840 | [
0.02442583069205284,
0.016235845163464546,
0.010272305458784103,
-0.029326181858778,
-0.007536749821156263,
-0.026375478133559227,
0.023316053673624992,
-0.008108146488666534,
-0.08648428320884705,
0.032847292721271515,
0.024164395406842232,
0.036125510931015015,
0.025760844349861145,
0.01... |
<p>I have a full set of sequences (432 observations to be precise) of 4 states $A-D$: eg</p>
<p>$$Y=\left(\begin{array}{c c c c c c c}
A& C& D&D & B & A &C\\
B& A& A&C & A&- &-\\
\vdots&\vdots&\vdots&\vdots&\vdots&\vdots&\vdots\\
B& C& A&... | g58670 | [
-0.02416922152042389,
-0.03129551559686661,
0.01604033075273037,
-0.0323466993868351,
-0.02529008500277996,
-0.04371970146894455,
0.03235074132680893,
0.04974480718374252,
0.0016819093143567443,
0.016642985865473747,
-0.02734064869582653,
0.029990222305059433,
0.0431850329041481,
0.0356620... |
<p>I am aware that multivariate non-normality in SEM can inflate the chi-square statistic and deflate standard errors of parameter estimates. I can deal with the latter (in AMOS) using bootstrapping procedures. But here's my specific question: <strong>while I can't correct for chi-square inflation in AMOS (as far as I ... | g13841 | [
0.003865751437842846,
-0.011773645877838135,
0.01205839216709137,
0.03664878383278847,
-0.009190826676785946,
-0.04785708710551262,
0.013756382279098034,
0.004177239257842302,
-0.002118323929607868,
0.06035127490758896,
0.026614058762788773,
-0.01075595710426569,
0.05614844709634781,
0.052... |
<p>I did a study monitoring the stability of an enzyme exposed to different conditions over time. Each day for 30 days, an aliquot was taken from each storage sample and analyzed in duplicate. I wanted to use statistical analysis to show mean changes during the 30 day experiment between the different conditions for an... | g42803 | [
-0.02202952280640602,
-0.04531377553939819,
-0.00013611212489195168,
-0.058625925332307816,
-0.027918551117181778,
-0.023314211517572403,
0.030350258573889732,
-0.0010155520867556334,
-0.03231831640005112,
0.0007782243774272501,
0.018493428826332092,
0.0362970232963562,
0.04216257482767105,
... |
<p>I am familiar with PCA as a linear transformation in order to align the axis of the IV space with the directions of maximal variance in order to possibly be able to reduce the dimensionality of the problem. Are there similar techniques (or can one use PCA itself) when facing a binary classification problem? Like a l... | g42804 | [
0.02675960585474968,
-0.03208199143409729,
0.019016340374946594,
-0.04807007312774658,
-0.04147832468152046,
-0.07090924680233002,
0.03229757398366928,
0.014538699761033058,
-0.05757589638233185,
-0.044251974672079086,
0.05504244193434715,
0.030238965526223183,
0.03322212025523186,
0.01445... |
<p>I'm reading up on RBMs and this is not obvious to me. I'm imagining RBMs being used for something like the Netflix Prize (since that was one of the papers I read on it). So you have a bunch of movies in the visible nodes, and the genre of those movies in the latent variables. But in the energy function, there are... | g58671 | [
-0.02991502918303013,
-0.011847453191876411,
-0.02026158757507801,
-0.027754133567214012,
0.03750509023666382,
-0.04770473390817642,
-0.018898235633969307,
0.06195339933037758,
-0.00666972016915679,
0.005173728335648775,
-0.014850368723273277,
0.10643210262060165,
0.026805046945810318,
-0.... |
<p>Suppose I have variables $X_j$, $j=1,\ldots,p$, some of which are correlated, and some continuous output $y$.</p>
<p>I want to rank the variables by importance. One way is to do an association test of each variable j with the output (linear regression for each variable). This ignores the correlations between the va... | g37785 | [
0.08247654139995575,
-0.04573377966880798,
-0.0005879088421352208,
-0.015858694911003113,
0.019972292706370354,
-0.07219313085079193,
0.016734033823013306,
-0.0033074438106268644,
-0.0004488046106416732,
0.052435796707868576,
0.017019230872392654,
-0.01937972381711006,
0.07846605777740479,
... |
<p>The objective of fisher linear discriminant analysis can be formulated as maximizing $\frac{Tr[X^TAX]}{Tr[X^TBX]}$ over $X$ where $A$ and $B$ are positive semi-definite with orthonormality constraints over X. </p>
<p>What is the significance of the orthonormality constraint in here? </p>
<p>I am also curious if r... | g106 | [
0.00015584065113216639,
-0.052608031779527664,
-0.00435965321958065,
-0.0422787070274353,
0.021229833364486694,
-0.10046643763780594,
0.01972956769168377,
0.031114233657717705,
-0.05513112246990204,
-0.003954785875976086,
-0.020052503794431686,
0.026183146983385086,
0.032435931265354156,
0... |
<p>I have been asking a number of questions about fitting mixed effects models. Thanks to a number of wonderful statisticians on here I have come far, and I thank you for you continued patience. I was going to ask this question live in chat but when I officially registered my username I lost my reputation and it has re... | g37786 | [
-0.004196082707494497,
-0.07444026321172714,
0.005306124687194824,
-0.02092440240085125,
-0.003113767597824335,
-0.004865074064582586,
0.0698929876089096,
0.010582678020000458,
-0.01985865831375122,
-0.04372362419962883,
0.008989729918539524,
-0.042233336716890335,
0.05480055510997772,
0.0... |
<p>I've been studying the bag of features (BoF) methods. I understand the basics and how it's done but I think I still am not good at the details. So here's my understanding of such methods:</p>
<p>Suppose you have a data base of images and you need to classify them. OK, then you must select local features in the firs... | g58672 | [
-0.01862945593893528,
0.015470294281840324,
0.024666238576173782,
-0.06404295563697815,
0.03907439112663269,
-0.046630118042230606,
0.04931110143661499,
0.06246611848473549,
-0.04818166792392731,
-0.015033258125185966,
-0.025889066979289055,
-0.01157375518232584,
0.08734998106956482,
0.071... |
<p>I was reading a paper by Cui et al., "Discover Breaking Events with Popular Hashtags in Twitter". I was trying to implement their hashtag instability algorithm, </p>
<p><img src="http://i.stack.imgur.com/2dQbs.png" alt="enter image description here"></p>
<p>I do not understand the actual algorithm, can some one pl... | g13842 | [
0.06095796078443527,
0.01675979048013687,
0.016918079927563667,
-0.035942573100328445,
0.023527538403868675,
-0.08904901146888733,
0.024797633290290833,
0.04849306121468544,
-0.044624123722314835,
-0.011457174085080624,
-0.05814099684357643,
-0.00843830406665802,
0.06409856677055359,
0.037... |
<p>I have a data set with tens of thousands of observations of medical cost data. This data is highly skewed to the right and has a lot of zeros. It looks like this for two sets of people (in this case two age bands with > 3000 obs each):</p>
<pre><code> Min. 1st Qu. Median Mean 3rd Qu. Max.
0.0 0... | g21424 | [
-0.013294809497892857,
-0.0015618635807186365,
-0.010084118694067001,
-0.014331325888633728,
-0.0369814857840538,
-0.017772957682609558,
0.021361587569117546,
-0.012237569317221642,
-0.027608251199126244,
0.006825317163020372,
0.009849539957940578,
0.03661911562085152,
0.01228051632642746,
... |
<p>I have been given two sets of data, one with 10,000 observations which is a subset of the other with 100,000 observations. It is <strong>claimed</strong> that the small dataset is a random sample of the large dataset.</p>
<p>How do I verify whether this is true?</p>
<p>I could compare the distributions, e.g. mean/... | g58673 | [
0.04155677556991577,
-0.032000552862882614,
-0.019699279218912125,
-0.05224289000034332,
-0.02775118313729763,
0.0023801373317837715,
-0.032833974808454514,
-0.015616647899150848,
-0.009449619799852371,
-0.0605325885117054,
0.0489567406475544,
0.041498828679323196,
0.034453313797712326,
0.... |
<p>Jerome Cornfield has written:</p>
<blockquote>
<p>One of the finest fruits of the Fisherian revolution was the idea of
randomization, and statisticians who agree on few other things have at
least agreed on this. But despite this agreement and despite the
widespread use of randomized allocation procedures in... | g58674 | [
0.028654182329773903,
0.008145682513713837,
-0.005408393684774637,
-0.048889413475990295,
0.013688935898244381,
-0.03964311257004738,
0.04026264324784279,
-0.024986229836940765,
0.015998810529708862,
-0.010123088955879211,
0.044109053909778595,
0.005236364435404539,
0.03138456121087074,
0.... |
<p>I have read about piecewise aggregate approximation (PAA) <a href="http://www.google.ca/url?sa=t&rct=j&q=&esrc=s&source=web&cd=9&ved=0CF4QFjAI&url=http://www.researchgate.net/publication/227001229_Mining_Time_Series_Data/file/32bfe51188657160b5.pdf&ei=Sdt3UomgMYaZiQL3sYHwCA&usg=AF... | g58675 | [
0.023423708975315094,
-0.015599711798131466,
0.006418945267796516,
0.006558527704328299,
-0.020702192559838295,
-0.016258448362350464,
0.015721529722213745,
0.0012680053478106856,
-0.0307308342307806,
0.0048911673948168755,
0.028109034523367882,
-0.0328715480864048,
0.058008160442113876,
0... |
<p>I'm looking to see if there is first:
- a main effect of the gender of the interviewer
- a main effect of the gender of the interviewee
And then if significant:
- the main effect of each gender interaction/dyad: 4 separate main effects - male/male, male/female, female/female, female/male (bowles)
- the main effect... | g58676 | [
-0.011441953480243683,
0.022697925567626953,
0.005794229451566935,
0.03128611668944359,
0.02175970748066902,
-0.02505478449165821,
-0.0023131459020078182,
-0.009053975343704224,
-0.042845677584409714,
0.011627809144556522,
0.022755686193704605,
-0.021472493186593056,
0.015678564086556435,
... |
<p>Given $ Y_1, Y_2..Y_n$ are iid from a distribution with pmf,<br>
$f(y) = a^{2}$ for $y=0$, </p>
<p>$f(y) = 2a(1-a)$ for $y=1$ , </p>
<p>$f(y) = (1-a)^{2}$ for $y=2$, where $0<a<1$.</p>
<p>For large n, calculate the approximate distribution of </p>
<p>a) $\sqrt {\bar{Y}}$ - Solution to part(a) posted as... | g58677 | [
-0.021454114466905594,
0.004421420861035585,
-0.003169025294482708,
0.005734665784984827,
0.0011480300454422832,
-0.023013891652226448,
-0.015043377876281738,
-0.01519156713038683,
-0.016625843942165375,
0.03022727183997631,
0.0076426053419709206,
0.04185338690876961,
0.028418827801942825,
... |
<p>I regularly see linear regression models written in this notation:</p>
<p>$y = a + \beta X + error$</p>
<p>I've never really pinned down what $error$ actually refers to. In the linear regression plotted below, does $error$ refer to the grey band, therefore the confidence interval for the prediction line?</p>
<p><... | g58678 | [
0.02062244713306427,
-0.02037174068391323,
-0.03132183849811554,
0.03488124907016754,
0.038484763354063034,
0.030276715755462646,
0.030742360278964043,
-0.016703836619853973,
-0.04178684204816818,
-0.07254241406917572,
-0.0054309857077896595,
0.06999248266220093,
0.031010715290904045,
-0.0... |
<p>Is it possible to interpret regression output when omitting the intercept? Can this omission be justified?</p> | g12086 | [
0.009419525973498821,
-0.02834000065922737,
0.0049474891275167465,
-0.0057858615182340145,
-0.016690248623490334,
-0.0018979007145389915,
0.03662134334445,
0.04955305531620979,
-0.025798937305808067,
-0.04451417177915573,
0.012538793496787548,
-0.013428928330540657,
0.018672697246074677,
-... |
<p>I apologise for the silliness of this question. I ran an e-learning experiment using a class of undergrads. Participation was voluntary, so only half of the class participated. </p>
<p>I know that my sample is the people who participated. Is the population all of the students in that class, or is the population all... | g58679 | [
-0.022877762094140053,
-0.02898787334561348,
0.013084999285638332,
-0.0412907637655735,
0.039443641901016235,
0.04813601076602936,
0.0018629074329510331,
-0.009409314021468163,
0.025358382612466812,
-0.018727349117398262,
0.016019636765122414,
0.03584825247526169,
0.04547940194606781,
0.00... |
<p>You have graduated from DePaul with a degree in HCI. Congrats! Your new boss tells you to survey 25 of the company's customers, asking them to rate on a 5-point scale their satisfaction with the website. He wants the margin of error to be 0.25. You know from previous experiments that the standard deviation is 1.0... | g58680 | [
-0.04488079249858856,
0.03552398085594177,
-0.009385746903717518,
0.020718131214380264,
0.003972792532294989,
-0.004744186531752348,
-0.011456076987087727,
-0.00832459982484579,
-0.01836744137108326,
-0.03225385397672653,
0.031554389744997025,
0.011651350185275078,
0.009043465368449688,
0.... |
<p>I'm characterizing a communication channel by measuring bit error rate (ber) as a function of 15 channel settings: ber = Func(settings[1:15]). The dataset is about 100,000 samples.</p>
<p>I wonder if I can use PCA to explore interaction of settings and their effect on the bit error rate. Specifically:</p>
<ol>
<li... | g13851 | [
0.020232951268553734,
-0.007802443578839302,
-0.013851400464773178,
-0.07851841300725937,
0.019130723550915718,
-0.05644119530916214,
0.07489802688360214,
-0.022156665101647377,
-0.06258166581392288,
-0.006330374162644148,
0.04126866161823273,
0.04077647253870964,
-0.0042742579244077206,
0... |
<p><strong>Short version:</strong> calculate variance of estimator of survival for a new subject (new covariates) where the coefficients for the covariates have been calculated from existing data.</p>
<p>Sorry this is so long, not sure quite where I'm going wrong. Feel free to edit if would be easier to have equations... | g58681 | [
0.021219462156295776,
-0.08469997346401215,
0.028069738298654556,
-0.017109422013163567,
-0.007068770006299019,
0.008433271199464798,
0.03682418912649155,
0.005604376085102558,
-0.04579642042517662,
0.015738585963845253,
-0.022160302847623825,
0.05889030173420906,
0.038497813045978546,
0.0... |
<pre><code> #Recursion of Binomial
bino <- function(n,p){
px <- (1-p)^n
X <- 0
Fx <- px
U <- runif(1)
while(Fx<U){
X<- X+1
px <- ((n-X+1)*p*px)/(X*(1-p))
Fx <- Fx+ px
}
return(X)
}
#inputs
N <- ... | g58682 | [
0.0245305597782135,
0.054659727960824966,
-0.021848076954483986,
-0.007865854538977146,
0.0348905511200428,
-0.052534203976392746,
0.06524941325187683,
0.03731445223093033,
-0.0095640504732728,
-0.051440127193927765,
-0.0186505988240242,
0.06724050641059875,
0.031102821230888367,
-0.018311... |
<p>For doing parallel analysis in my real data to determine the number of its dimension, i need to simulate binary data matrix with n(number of case) by k(number of items). the p-values of these simulated data must be equal to the corresponding p-values of items in sample real data with n cases and k items. but unlike ... | g58683 | [
0.06806112825870514,
0.037519555538892746,
0.017049003392457962,
-0.05956849455833435,
0.013212218880653381,
-0.03688916936516762,
0.012645943090319633,
0.03297383710741997,
-0.06369992345571518,
-0.026133328676223755,
-0.0035239586140960455,
0.015021448954939842,
-0.0053280857391655445,
0... |
<p>I'm looking for some kind of function I can compute on a bunch of numbers. The idea is that if I increase <em>all</em> numbers by some coefficient (say 2) the value of this should not change. </p>
<p>e.g. </p>
<p>f(2,4,6,9)= f(4,8,12,18)</p>
<hr>
<p>Edit: I know I can just divide all the numbers by the largest ... | g13856 | [
0.0050711859948933125,
0.009783892892301083,
-0.03143511340022087,
-0.041273247450590134,
-0.021479444578289986,
-0.056570347398519516,
0.025686392560601234,
0.026348868384957314,
-0.07208137959241867,
-0.02839452400803566,
-0.011718515306711197,
0.004587036557495594,
0.0839647725224495,
-... |
<p>I got the data, and plot the distribution of the data, and use the qqnorm function, but is seems doesn't follow a normal distribution, so which distribution should I use to discribe the data?</p>
<p>Empirical cumulative distribution function
<img src="http://i.stack.imgur.com/xnQpe.png" alt="enter image description... | g58684 | [
0.05612311139702797,
-0.03706606850028038,
-0.002642545150592923,
-0.054150521755218506,
-0.03230228275060654,
0.01565929874777794,
0.009496399201452732,
-0.004715207032859325,
-0.027775611728429794,
-0.06805513054132462,
0.05222520977258682,
-0.011998988687992096,
0.07237505912780762,
-0.... |
<p>Actually, I am trying to learn a model using stochastic gradient descent. I am using just a small subset of my entire data at a time to make each iteration. As far as I know, stochastic gradient descent can fluctuate but still moves towards the maximum point. </p>
<p>I am outputting the value of the objective funct... | g13857 | [
0.010762825608253479,
-0.03135552629828453,
0.015776991844177246,
0.01658981665968895,
0.005207679700106382,
0.027004452422261238,
0.039640504866838455,
-0.0015281297964975238,
-0.09693754464387894,
-0.009300745092332363,
-0.032181814312934875,
0.02478599175810814,
0.04475324600934982,
0.0... |
<p>After having found <a href="http://cran.r-project.org/web/packages/coin/index.html" rel="nofollow">the R-package <code>coin</code></a>, I have a question. </p>
<p>For example, to get an exact p-value, I could use the function <code>wilcox.exact</code> in the <code>exactRankTests</code> R package.</p>
<p>But if I d... | g58685 | [
0.006908003706485033,
-0.0169225987046957,
0.004408692475408316,
-0.044756341725587845,
0.07075876742601395,
-0.026802174746990204,
0.0024852959904819727,
-0.011143981479108334,
-0.06297493726015091,
0.010447235777974129,
-0.046125639230012894,
0.03621157258749008,
-0.0071238125674426556,
... |
<p>I am trying to use JAGS to deal with the following multivariate state space model.</p>
<p>$Y_t=X_t\theta_t+\epsilon_t$</p>
<p>$\theta_t=\theta_{t-1}+\nu_t$</p>
<p>JAGS code is neat but JAGS is running too slow when I am monitoring several hundred variables in the model. I decide to use forward filtering backward ... | g58686 | [
-0.0017228970536962152,
0.016543272882699966,
-0.008733795955777168,
-0.06789736449718475,
-0.03359951078891754,
-0.06708432734012604,
0.013759784400463104,
0.013090252876281738,
-0.020091067999601364,
-0.001331452396698296,
0.029437348246574402,
0.00019895713194273412,
0.060278233140707016,... |
<p>Provided I have the value of the Friedman's chi-squared statistic, is there any way to get the corresponding P-value without copying the whole table of critical values in my Python program?</p> | g58687 | [
0.011831499636173248,
0.008639076724648476,
-0.002118726959452033,
-0.022874413058161736,
0.027139537036418915,
-0.035169102251529694,
-0.029144613072276115,
0.027705026790499687,
-0.029706330969929695,
0.0041526625864207745,
-0.03496672213077545,
0.01311188843101263,
0.06130498647689819,
... |
<p>When describing the condition number of a correlation matrix I have seen is described as the ratio of the singular values (from singluar value decomposition).</p>
<p>I have also seen it described as the ratio of the eigenvalues (from PCA analysis).</p>
<p>Can both be correct (under say different norms)?
If so whi... | g58688 | [
0.02733905054628849,
-0.04105251282453537,
-0.0009173066355288029,
-0.0428922176361084,
0.004205772653222084,
-0.002213016152381897,
0.061720676720142365,
0.08075742423534393,
0.007698032073676586,
-0.038833484053611755,
0.06000783294439316,
-0.030361736193299294,
0.03608493506908417,
0.05... |
<p>I have 10 millions of filenames and I need to determine whether filename corresponds to some movie or video game. For this I initially thought to compare filenames using Levenshtein distance with imdb list <a href="ftp://ftp.funet.fi/pub/mirrors/ftp.imdb.com/pub/" rel="nofollow">ftp://ftp.funet.fi/pub/mirrors/ftp.i... | g58689 | [
0.02929697558283806,
-0.018611591309309006,
-0.025814302265644073,
-0.07072310894727707,
-0.03161255642771721,
-0.09683165699243546,
-0.0033663343638181686,
0.014385070651769638,
-0.061917126178741455,
-0.0006188579136505723,
0.0032029179856181145,
-0.046479951590299606,
0.08417709916830063,... |
<p>"Independent" variables: time spent (% at work, % sleeping, % exercising), body mass composition (% fat, % muscle, % bone)</p>
<p>Dependent variable: Smoker (1) or Non-Smoker (0)</p>
<p>What kind of regression model should I use when subsets of the "independent" variables are percentages and are therefore not comp... | g58690 | [
-0.016875075176358223,
-0.03419935703277588,
-0.019629448652267456,
0.03556326404213905,
-0.025663912296295166,
-0.029738880693912506,
0.022075951099395752,
-0.019304819405078888,
-0.010712062940001488,
-0.006926926784217358,
0.027783434838056564,
0.01359570398926735,
-0.0011383079690858722,... |
<p>When I use GLMs I can use the option <code>family="Gamma"</code> for analysing data consisting of positive real numbers. Also package <code>gbm</code> provides a large number of distributions to choose from, but there's none that matches the gamma distribution. Which distribution should I choose?</p> | g58691 | [
0.04610763490200043,
-0.0016450905241072178,
-0.02130751498043537,
-0.02710835449397564,
0.025188392028212547,
-0.0018485230393707752,
-0.0074461218900978565,
-0.021716412156820297,
-0.049461983144283295,
-0.04858296364545822,
0.04254274442791939,
-0.018494516611099243,
0.04840806871652603,
... |
<p>How do you calculate and conceptualize a confidence interval for a binary outcome? </p>
<p>Say I have 100 speakers and 30 speakers fail. If I want to calculate a confidence interval for the failure rate of speakers, which the company tells me is 25 percent, what would I do? Would I have to assume that the failure r... | g49535 | [
0.0036524764727801085,
0.005833342205733061,
-0.017872175201773643,
-0.013859101571142673,
-0.019507087767124176,
0.010337288491427898,
0.001364533556625247,
0.003679454093798995,
-0.06226998195052147,
-0.0784652978181839,
-0.01900492236018181,
0.05754704773426056,
0.014208313077688217,
-0... |
<p>I have a question about model selection when using AIC/BIC. So, if two model structures are totally different, can I still directly apply AIC and BIC?
Also, for a hierarchical model, how to compute the total number of parameters when computing AIC and BIC?
Thanks.</p> | g13859 | [
0.036107033491134644,
-0.025873305276036263,
0.023452933877706528,
0.005739628802984953,
0.04915482923388481,
-0.07879824936389923,
0.06962823867797852,
0.04985297471284866,
-0.039126116782426834,
0.003845901694148779,
-0.03311685100197792,
0.04594598338007927,
0.05732305720448494,
0.00430... |
<p>The <code>ranef</code> function provides a way to extract the random effects coefficients from an <code>lme</code> model.</p>
<p><strong>What is the function to extract random effects for a <code>plm</code> model?</strong></p>
<p>Find below R code from the JSS paper (<a href="http://www.jstatsoft.org/v27/i02/" rel... | g58692 | [
-0.023524805903434753,
-0.029309814795851707,
-0.011855462566018105,
-0.05058162286877632,
0.03193982318043709,
0.016304045915603638,
0.03966982662677765,
-0.004176517017185688,
-0.013872073031961918,
-0.03477175906300545,
-0.06181826815009117,
0.02983124740421772,
-0.012932684272527695,
0... |
<p>I have some concerns regarding factor analysis and especially about combining the factor analysis for an ordinal scale (categorical data) - CATPCA with conventional PCA.
Basically, I need to enter my set of variables in CATPCA, take the transformed variables from CATPCA and introduce them in conventional PCA (becaus... | g58693 | [
-0.026523081585764885,
-0.031110640615224838,
-0.0019050897099077702,
-0.09802653640508652,
0.034520912915468216,
-0.02186596766114235,
0.02880166843533516,
-0.004344898741692305,
-0.044349294155836105,
0.02720748260617256,
-0.008723699487745762,
-0.0007141340174712241,
0.02314268983900547,
... |
<p>I have a Audio time-series, to which I'm trying to detect the most significant parts of the signal, i.e. the voiced parts and forget the unvoiced parts. </p>
<p>$$
T = [0, 0, 1, 1, .....n]
$$</p>
<p>I then compute the Spectral result of the time series, which, gives me a dimensional frequency representation of the... | g58694 | [
-0.013234151527285576,
-0.01900942623615265,
-0.018097957596182823,
-0.05916835740208626,
-0.010985875502228737,
-0.05276783928275108,
0.0047174300998449326,
0.04116657003760338,
-0.053764935582876205,
0.02312433160841465,
-0.021195868030190468,
0.04098374769091606,
0.04369630292057991,
-0... |
<p>Let $D_n$ be the demand for an item at a store on day $n$. Suppose that $D_n$ is a sequence of independent and identically distributed (i.i.d.) random variables with probability mass function:</p>
<p>$p_k = P(D_n = k)$</p>
<p>Suppose the store follows the following inventory management policy. If inventory at
the ... | g58695 | [
-0.021148398518562317,
0.0071069346740841866,
-0.009970435872673988,
0.004049121402204037,
-0.01837364211678505,
0.0299998726695776,
0.023326892405748367,
-0.02201942354440689,
-0.04123875871300697,
-0.013205522671341896,
-0.041816405951976776,
-0.07156047224998474,
0.01567922532558441,
0.... |
<p>I saw that questions regarding sample sizes and PCA are asked here quite frequently. However, I was not able to find exactly the information I need.</p>
<p>I plan to do a psychometric study and conduct a principal component analysis on the data. The data I want to collect will be three-dimensional, e.g. participant... | g13861 | [
-0.0037349367048591375,
0.022021770477294922,
0.006097549106925726,
-0.07417143136262894,
0.012783944606781006,
-0.03022191673517227,
0.015178903937339783,
0.013322585262358189,
-0.049670446664094925,
-0.00782308354973793,
0.06429333984851837,
-0.024050520732998848,
-0.007576156873255968,
... |
<p>I know, I can't use convolution.
I have two random variables A and B and they're dependent.
I need Distributive function of A+B</p> | g58696 | [
0.009012428112328053,
-0.03752022609114647,
-0.0027978334110230207,
-0.06231948733329773,
-0.05090228468179703,
-0.036657899618148804,
0.008890935219824314,
0.01342804916203022,
-0.04169359430670738,
-0.05572826415300369,
-0.021355023607611656,
0.035284798592329025,
0.016998616978526115,
0... |
<p>How can I estimate a model where </p>
<p>Y ~ X1 + X2 + X3</p>
<p>X1 ~ Z1 + Z2</p>
<p>X2 ~ Z1 + Z2</p>
<p>X3 ~ Z1 + Z2</p>
<p>where Y may/may not be correlated with Z1 and Z2. Is there a R procedure that I could use to estimate the model.</p>
<p>Thanks a lot for your help.</p> | g13863 | [
-0.0016623971750959754,
-0.059971921145915985,
0.006799057126045227,
0.006315692327916622,
0.003044446464627981,
-0.027672074735164642,
0.03912433236837387,
0.016538012772798538,
0.0001685204915702343,
0.022095147520303726,
-0.01577659696340561,
-0.0024805357679724693,
0.005383539479225874,
... |
<p>Can anyone answer the question or direct me to the proper resources - ESPECIALLY for sampling error effect on the coefficients? How would the coefficients be affected if the independent variables came from one data set while the dependent variable came from a different data set? </p> | g58697 | [
0.0018988329684361815,
-0.023011375218629837,
-0.004950232338160276,
0.0013891877606511116,
-0.0005036700167693198,
-0.01151764951646328,
0.012778809294104576,
-0.005422593094408512,
-0.05492530018091202,
-0.0012993839336559176,
-0.04079151898622513,
0.06674802303314209,
0.011129504069685936... |
<p>I'm trying to explain a binary outcome (cardiovascular disease) with a categorical predictor (gene level, coded as 0, 1, or 2 depending on the number of risk alleles present).
I'm trying to determine if the effect of the gene on cardiovascular disease is due to its known effect on an additional continuous covariate ... | g58698 | [
0.03352554515004158,
-0.02053222432732582,
0.006767264101654291,
0.026940619572997093,
0.011978968046605587,
-0.03305564448237419,
0.059931881725788116,
0.03529437258839607,
-0.012095932848751545,
-0.015756066888570786,
0.00438051950186491,
0.036168307065963745,
0.042653411626815796,
0.036... |
<p>I have a situation in which that there are 4 cases with a condition per 1000 people surveyed (binary). I am interested in performing a logistic regression to determine the risk factors (binary). Is it possible to perform such an analysis with SPSS? </p> | g13866 | [
0.006545158103108406,
-0.014863911084830761,
0.01345328614115715,
-0.018470361828804016,
-0.009799130260944366,
-0.04982922226190567,
-0.027774760499596596,
0.025558659806847572,
-0.032779913395643234,
-0.042602021247148514,
0.049686793237924576,
0.011143646202981472,
0.029991257935762405,
... |
<p>if there is no plausible sampling frame available for surveying, how will one obtain a representative sample of size n.</p>
<p>In the textbooks they use SRS, stratified, cluster, and systematic but these all imply a sampling frame is available like a telephone book etc.</p>
<p>So say for example, there is a websit... | g58699 | [
-0.012135687284171581,
0.035110972821712494,
0.007124519441276789,
-0.06421610713005066,
-0.016531478613615036,
0.015659986063838005,
-0.018287163227796555,
0.055334825068712234,
0.017038317397236824,
-0.022501789033412933,
0.03353530168533325,
-0.04718133062124252,
0.0557185523211956,
0.0... |
<p>Now I am using MATLAB, and found one of its function named <code>crossvalind</code>, which provides lots of methods for cross validation, including some that I wasn't able to find on this site.</p>
<pre><code>[TRAIN,TEST] = crossvalind('LeaveMOut',N,M), where M is an integer,
returns logical index vectors for cross... | g58700 | [
0.027341477572917938,
-0.0062522427178919315,
0.032016124576330185,
-0.015219592489302158,
-0.003728943644091487,
-0.004328424111008644,
0.05315838009119034,
0.011417237110435963,
-0.07269922643899918,
-0.0031310052145272493,
0.006821383722126484,
-0.0084168566390872,
0.015479828231036663,
... |
<p>I need to perform a two-way ANOVA on my data. My data is from a non-normal population. Apparently there is no two or three factor test for non-normal populations. I realized I need to transform my data, but I'm unsure about which transformation to perform on my data, I don't know which is the most appropriate. I don... | g58701 | [
-0.009719371795654297,
0.015730388462543488,
0.010852700099349022,
-0.010032529011368752,
-0.0014663499314337969,
0.029155369848012924,
0.02487719990313053,
0.025847163051366806,
-0.0075792609713971615,
-0.00464684097096324,
-0.01619371771812439,
0.029828611761331558,
-0.015288421884179115,
... |
<p>I've seen various theoretical treatments of graphics, such as the <a href="http://rads.stackoverflow.com/amzn/click/0387987746">Grammar of Graphics</a>. But I have seen nothing equivalent with regards to tables. Over the while I have developed an informal model of good practice in table design.
However, I'd like to... | g58702 | [
0.02208850160241127,
0.04945719242095947,
0.0078017194755375385,
-0.09289810061454773,
-0.07699954509735107,
-0.028062129393219948,
-0.030369697138667107,
0.05248519405722618,
-0.025464026257395744,
0.02765406109392643,
0.07764919847249985,
-0.009132849983870983,
0.08360262215137482,
0.017... |
<p>I am reading the paper available at this link:
<a href="https://drive.google.com/file/d/0B2_rKFnvrjMARnU1QjB4anR3RDA/edit?usp=sharing" rel="nofollow">https://drive.google.com/file/d/0B2_rKFnvrjMARnU1QjB4anR3RDA/edit?usp=sharing</a> </p>
<p>I am having trouble understanding section 5.1 (page 2741).</p>
<p>Essential... | g58703 | [
0.019712382927536964,
0.009100989438593388,
-0.017427314072847366,
-0.047546520829200745,
0.054776158183813095,
-0.015462730079889297,
0.029582858085632324,
-0.08777030557394028,
-0.0472964346408844,
0.01154064480215311,
-0.032468121498823166,
0.07086414843797684,
-0.010225001722574234,
0.... |
<p>In a multiple linear regression, why is it possible to have a highly significant F statistic (p<.001) but have very high p-values on all the regressor's t tests?</p>
<p>In my model, there are 10 regressors. One has a p-value of 0.1 and the rest are above 0.9</p>
<hr>
<p>For dealing with this problem see the <a... | g49828 | [
0.06071161478757858,
0.023416630923748016,
-0.018492715433239937,
0.02004542574286461,
0.08385555446147919,
-0.011223508045077324,
-0.015667179599404335,
0.06620386987924576,
-0.032153867185115814,
-0.07428598403930664,
-0.0327577218413353,
-0.013578474521636963,
0.0022094217129051685,
0.0... |
<p>Effects of growth hormone (GH) replacement with recombinant human GH on bone and mineral metabolism were studied in 36 GH-deficient children. Several outcomes, including serum ionized calcium levels, were assessed at pretherapy (zero months) and 1, 3, 6, 9 and 12 months after the beginning of therapy. Simple linear ... | g58704 | [
0.02054016850888729,
0.03319904953241348,
-0.0032225975301116705,
0.05173734575510025,
-0.0007721593719907105,
0.009867975488305092,
0.04073697328567505,
-0.009959476999938488,
-0.038626763969659805,
0.022571053355932236,
-0.07126584649085999,
0.006697343662381172,
-0.014477289281785488,
-... |
<p>Anyone got library or code suggestions on how to actually <strong>plot a couple of sample trees</strong> from: </p>
<pre><code>getTree(rfobj, k, labelVar=TRUE)
</code></pre>
<p>(Yes I know you're not supposed to do this operationally, RF is a blackbox, etc etc. I want to visually sanity-check a tree to see if any ... | g43021 | [
-0.017084989696741104,
-0.04049079865217209,
0.003940474707633257,
-0.05039080232381821,
-0.02742917276918888,
-0.06185290962457657,
-0.03245482221245766,
0.009203603491187096,
0.015231175348162651,
0.01648557372391224,
0.07248223572969437,
0.006205984391272068,
0.0376475565135479,
0.02162... |
<p>I am trying to convert state-level poll results for 2012 U.S. presidential election into state-level probabilities of each candidate winning. To achieve that, I am using the logistic function, which conveniently goes to 0 or 1 as poll results deviate from 50%, and also makes the probability of each candidate winning... | g58705 | [
-0.004997179377824068,
-0.009770517237484455,
0.013191969133913517,
-0.024961987510323524,
0.009896638803184032,
-0.019667306914925575,
-0.02106938697397709,
-0.004300128668546677,
0.011877781711518764,
0.01147364266216755,
0.03304312378168106,
0.012169523164629936,
0.07809063792228699,
-0... |
<p>I'm following an undergraduate course on timeseries using OxMetrics and wanted to reproduce som results in R</p>
<p>Estimating an ARMA(3,3) model:</p>
<pre><code>arima(temp,c(3,0,3))
</code></pre>
<p>using stats package and also TSA package results in following error:</p>
<pre><code>Error in arima(temp, c(3, 0... | g58706 | [
0.023781757801771164,
-0.07233916968107224,
-0.004430120810866356,
0.014495350420475006,
0.0248009841889143,
0.004814718384295702,
0.014102696441113949,
0.00486993370577693,
-0.049002308398485184,
0.05243970826268196,
-0.00982232578098774,
-0.003665473312139511,
0.05201636254787445,
0.0433... |
<p>I want to test if two regression coefficients from two separate regressions are significantly different from each other. In particular I want to test from the model
$$
\begin{aligned}
x1_{(t)} &= \mu1 + a*x1_{(t-1)} + b*x2_{(t-1)} + e1 \\
x2_{(t)} &= \mu2 + c*x1_{(t-1)} + d*x2_{(t-1)} + e2
\end{aligned}
$$
... | g42855 | [
0.01035651471465826,
-0.06513747572898865,
-0.008191804401576519,
0.010618952102959156,
0.017850814387202263,
-0.0732601210474968,
0.05891524255275726,
0.04865146428346634,
-0.03398236259818077,
0.017252657562494278,
-0.0028075245209038258,
0.04946589469909668,
0.012251731008291245,
-0.032... |
<blockquote>
<p><strong>Possible Duplicate:</strong><br>
<a href="http://stats.stackexchange.com/questions/26271/comparing-two-classifier-accuracy-results-for-statistical-significance-with-t-te">Comparing two classifier accuracy results for statistical significance with t-test</a> </p>
</blockquote>
<p>I coded ... | g49536 | [
0.01818082667887211,
-0.030368613079190254,
0.014810806140303612,
-0.02049117721617222,
0.02519121766090393,
0.0055992491543293,
0.02899465523660183,
0.04711427167057991,
-0.03729720413684845,
-0.007211234886199236,
0.044556476175785065,
0.00764473108574748,
0.07593413442373276,
0.06668135... |
<p>I'm new to R and statistics in general. My background is in Software Development, and I've tasked myself to solve a problem in a 3rd party application. This application is a Game, and I'd like to measure the existence of a performance problem.</p>
<p>I measure performance in Frames Per Second (FPS), and for some r... | g58707 | [
-0.007307480089366436,
0.0225362591445446,
-0.02182350493967533,
-0.08021111786365509,
0.006105382461100817,
-0.043160565197467804,
0.07664037495851517,
-0.03699713572859764,
-0.04497619718313217,
-0.01568177342414856,
-0.023648902773857117,
0.04344584792852402,
0.007874450646340847,
0.054... |
<p>When does data analysis cease to be statistics ?</p>
<p>Are the following examples all applications of statistics ?: computer vision, face recognition, compressed sensing, lossy data compression, signal processing.</p> | g58708 | [
0.06400425732135773,
-0.007510592695325613,
0.010807384736835957,
0.014350571669638157,
-0.006018121261149645,
-0.05417908728122711,
0.04514346271753311,
-0.02269364893436432,
-0.020867517217993736,
-0.048599131405353546,
-0.006826026365160942,
0.019038598984479904,
0.06037668138742447,
-0... |
<p>I have conducted two user studies and in my studies I didn't have control over the group sizes. In each study users were put in groups and they were asked to perform some group activities. Here is the way the groups were arranged:</p>
<ul>
<li><strong>Study 1 (Control Groups):</strong>
In this study 20 people parti... | g42864 | [
-0.01888224110007286,
0.006001042202115059,
-0.001686768839135766,
-0.036244947463274,
-0.004940147511661053,
-0.010675943456590176,
0.010385346598923206,
-0.032426074147224426,
-0.041877347975969315,
0.000703060592059046,
0.061170823872089386,
-0.02852596901357174,
0.0298891793936491,
0.0... |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.