question stringlengths 37 38.8k | group_id stringlengths 2 6 | sentence_embeddings listlengths 768 768 |
|---|---|---|
<p>Has anyone worked with semi parametric methods like Cosslett (1983) or Ichimura or Klein-Spady for binary outcomes? I was wondering if anyone has any R code that he/she could share?</p> | g64985 | [
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<p>I have the following situation (4 independent treatment groups, each group is tested for 3 dependent variables) and was wondering what would be the best to do:</p>
<ol>
<li>What is the best test to do? I have always done MANOVA with post hoc for each dependent variable. Now someone said it should be repeated measur... | g64986 | [
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<p>I know PSO is intended for optimization, but I saw in an article that survey techniques of ML to the Intrusion detection problem (KDD 99 dataset):</p>
<blockquote>
<p>Chen et al. [55] demonstrated a ‘‘divide-and-conquer’’ approach to incrementally learning a classification rule set using a standard PSO algorithm. ... | g64987 | [
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<p>I have problem with exercise, I didn't solve. Give an example on $\Omega=\{a,b,c\}$ in which</p>
<p>$$E(E(X|F_1)|F_2)\neq E(E(X|F_2)|F_1)$$</p>
<p>Thanks very much for your help.</p> | g64988 | [
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<p>I am trying to find the most appropriate characteristic distribution of repeated measurements data of a certain type.</p>
<p>Essentially, in my branch of geology, we often use radiometric dating of minerals from samples (chunks of rock) in order to find out how long ago an event happened (the rock cooled below a th... | g23349 | [
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<p>Let $X_1,X_2,...,X_n$ be a random sample from a uniform distribution on $(\mu-\sqrt 3\sigma,\mu+\sqrt3\sigma)$.</p>
<p>Here the unknown parameters are two, namely $\mu$ and $\sigma$, which are the population mean and standard deviation.</p>
<p>Find the point estimator of $\mu$ and $\sigma$.</p>
<p>I have tried to... | g23350 | [
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<p>When the point estimator under consideration has a pdf, then </p>
<p>$P[T=\tau(\theta)]=0 $ </p>
<p>where $\tau(.)$ is some function of parameter $\theta$</p>
<p>$T$ is an estimator of $\tau(\theta)$</p>
<p>But I did many exercises to find point estimators of the parameters of density functions.</p>
<p>For exam... | g23353 | [
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<p>My study has 6 continuous predictor variables and a dichotomous criterion variable. The IRB wants me to provide a power analysis, which I take to mean how I decided on number of participants to recruit. </p>
<p><strong>How do I use a power analysis to compute minimum number of participants needed?</strong></p>
<... | g64989 | [
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<p>I want to show that
$$\newcommand{\cov}{\operatorname{cov}}\newcommand{\d}{\mathrm{d}}\cov(x,y) = \iint (F_{X,Y}(x,y) - F_X(x)F_Y(y))\,\d x\,\d y$$
However, I have no idea how to start. I know that
$$\cov(x,y) = \iint (x-\mu_X)(y-\mu_Y)f_{X,Y}(x,y)\,\d x\,\d y = \iint xyf_{X,Y}(x,y)\,\d x\,\d y - \mu_x \mu_y$$
whe... | g64990 | [
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<p>How would I go about estimating the number of active Twitter users that drive to work each morning worldwide?</p>
<p>What data would I need to know, and how would I approach this problem using those data points?</p> | g64991 | [
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<p>I'm writing a series of blog posts on the basics of machine learning, just for fun, mostly to validate my understanding of Andrew Ng's class. As I'm currently studying generalized linear models (GLMs), my method so far is to generate a small 2D dataset for each regression algo, and apply batch gradient descent on th... | g23034 | [
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<p>Let $X$ be a random variable with expected value $\mu$. I need an upper bound on $\Pr( X < \mu )$. All of the bounds I could find deal with something like $\Pr( X < \mu - a)$ and become trivial if $a = 0$.</p>
<p>In the particular case I am interested in $X$ is a finite sum of independent random variables, ... | g43187 | [
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<p>I'm a philosophy undergraduate. I've recently read about analogical inferences. When making inferences by analogy, we observe that many of the properties of the analogues are the same, then infer that the rest of the properties are probably the same. </p>
<p>For example, an analogy between sets of the vital propert... | g64992 | [
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<p>The Gaussian, or squared exponential covariance is $k_{SE}(s,t) = \exp \left\{ -\frac{1}{2l} (s - t)^2 \right\}$. It is a common covariance function used in Gaussian processes. The Karhunen-Loeve expansion is an orthonormal decomposition of sample paths of a Gaussian process. If $g(t)$ is a sample path from a Gaussi... | g64993 | [
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<p>How is "a testing procedure is valid" defined?</p>
<p>For example, in <a href="http://en.wikipedia.org/wiki/Fisher%27s_exact_test" rel="nofollow">Wikipedia</a></p>
<blockquote>
<p>Fisher's exact test is a statistical significance test used in the
analysis of contingency tables. Although in practice it is emplo... | g64994 | [
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<p>I have a random variable $Z$ with some CDF $F(z)$ and quantile $Q(p) \equiv F^{-1}(p)$. I have $Q(p)$ in closed-form but not $F(z)$.</p>
<p>Create a new random variable $\hat{Z}$ defined so that the CDF $\hat{F}(z) \equiv F(z)^{\kappa}$ for some $\kappa > 0$. (it sounds like this is not necessarily the CDF of $... | g64995 | [
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<p>Suppose X is the design matrix of my experiment of which I want to model a linear regression model. Such a design matrix can be created by (in this example it is a full factorial design)</p>
<pre><code>library(BHH2)
Des2 <- ffDesMatrix(5)
</code></pre>
<p>Now, a contrast matrix can be obtained by the following ... | g23364 | [
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<p>I need some help understanding the relation between the maximum likelihood and Gaussian mixture models. I have seen that there is a relationship between the expectation maximization algorithms and these two terms, but I could not quite understand the relation well enough. Could some please give me an example of how ... | g64996 | [
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<p>I am told that wealth follows a Pareto distribution, and that IQ follows a Pearson IV distribution (<a href="http://www.abelard.org/burt/burt-ie.asp" rel="nofollow">http://www.abelard.org/burt/burt-ie.asp</a>). Both Pareto and Pearson IV distributions have long tails. Which one is longer?</p>
<p>In plain language: ... | g64997 | [
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<p>I do not understand why the following equality holds (taken from Cameron & Trivedi 2005: <em>Microeconomtrics</em>):</p>
<p>$\hat{\underline{\beta}}_{OLS}=(\textbf{X}'\textbf{X})^{-1}\textbf{X}'\textbf{y}=(\sum_{i=1}^{n}\textbf{x}_i\textbf{x}_{i}^{'})^{-1}\sum_{i=1}^{n}\textbf{x}_iy_i$</p>
<p>The notation is</... | g64998 | [
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<p>I've done 15 imputations and am now running various tests on the new data, but all I'm really interested in is the pooled results at the end. The long list of imputations (especially in a test like an independent T) is unnecessary and I'd like to just hide all of it/suppress it when I run any tests on imputed data. ... | g64999 | [
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<p><strong>Short version:</strong> I have two time series: steps taken and change in body fat mass. Both are daily data. I am trying the estimate the effect of the number of steps taken on the change in body fat mass. I am especially interested in getting a point estimate and interval for for where the effect goes from... | g23371 | [
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<p>I've seen this question asked before, but I have yet to come across a definitive source answering the specific questions:</p>
<ul>
<li>What's the most appropriate statistical test to apply to a small A/B test?</li>
<li>What's the R code and interpretation to analyze a small A/B test?</li>
</ul>
<p>I'm running a sm... | g65000 | [
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<p>I'm rather evangelistic with regards to the use of likelihood ratios for representing the objective evidence for/against a given phenomenon. However, I recently learned that the Bayes factor serves a similar function in the context of Bayesian methods (i.e. the subjective prior is combined with the objective Bayes f... | g23373 | [
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<p>For my thesis there's a big chance that I will need some sort of mixed-effects specification. I have some (non-syntax) experience with SPSS but feel that it won't suffice for my analysis. I have very basic knowledge in Stata and decided to experiment more with that package. </p>
<p>I decided to try and replicate re... | g65001 | [
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<p>I'm currently looking at a 2x2 Repeated Measure Anova for an undergrad project but I'm struggling to find information about which means to report.</p>
<p>I will be reporting the Within-Subjects Anova,the Interaction and the Between Subjects Anova.</p>
<p>I have a Profile Plot to show the Estimated Marginal Means o... | g65002 | [
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<p>I'm a postgraduate economics student but not of the statistically inclined sort :)</p>
<p>Im running a regression to estimate the likelihood of a patent being litigated. I have two dummies for the patent owner type; let's call them <code>SmallFirm</code> and <code>LargeFirm</code>. The reference category is indivi... | g65003 | [
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<p>Consider the nested logistic regression model’s following interpretation. </p>
<p>A person repeatedly chooses between two different options. These options feature different levels of the same features (e.g. car characteristics). In some cases, the person will choose option 1, in some cases the person will choose op... | g62 | [
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<blockquote>
<p><strong>Possible Duplicate:</strong><br>
<a href="http://stats.stackexchange.com/questions/19891/interpreting-main-effect-and-interaction">Interpreting main effect and interaction</a> </p>
</blockquote>
<p>In a GLM, I had one categorical predictor and one covariate. To ensure the covariate was c... | g49701 | [
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<p>I tried to use random forest to classify microarray data. Basing on research of L.Breiman and Tao Shi, I constructed a synthetic data base using bootstrap methods (Assuming it is a matrix with samples on row and genes on column, for each gene in each sample, values are selected with replacement in the gene column, d... | g43210 | [
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<p>Van der Vaart [1] uses the term Z-estimation for the estimating equations approach.
Is this the first use of the term?</p>
<p>[1] Vaart, A. W. Van Der. Asymptotic Statistics. Cambridge University Press, 2000.</p> | g23379 | [
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0.05567661672830582,
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0.0360906757414341,
0.012973341159522533,
0.017994871363043785,
0.030196724459528923,
... |
<p>What is exactly the difference among <strong>Indicator, Index, Variable and Measure</strong>? I would appreciate some reference.</p> | g23381 | [
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0.0073112500831484795,
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<p>I'm interested in fitting a model to several types of time series that all behave similarly:</p>
<ul>
<li>Depth of a work queue</li>
<li>Disk space available</li>
<li>Idle CPU time available</li>
</ul>
<p>None of these values can go below zero, but otherwise their behavior is relatively independent of value. (e.g.... | g65004 | [
-0.032628025859594345,
0.07785564661026001,
0.0002274646976729855,
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0.003213053336367011,
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0.020049139857292175,
0.03526011481881142,
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<p>I would like to make a NMDS with biomass of different prey groups in stomach content of fish.</p>
<p>I have already made one where the data matrix consists of 0 and 1, and this one went fine but are not able to do it when adding the actual weights.</p>
<p>I have used the MASS and vegan package. When using binomial... | g43224 | [
0.015443050302565098,
-0.015956701710820198,
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0.029801765456795692,
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0.07668139040470123,
... |
<p>I conducted a glm.nb by </p>
<pre><code>glm1<-glm.nb(x~factor(group))
</code></pre>
<p>with group being a categorial and x being a metrical variable. When I try to get the summary of the results, I get slightly different results, depending on if I use <code>summary()</code> or <code>summary.glm</code>. <code>su... | g49638 | [
-0.02253430336713791,
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0.03936740383505821,
0.01234911847859621,
-0... |
<p>We know that the two canonical Levy processes, namely the Wiener process and Poisson process, are both memoryless, so I wonder if there are any Levy process that is not memoryless. Specifically, are these two properties equivalent: </p>
<p><a href="http://en.wikipedia.org/wiki/L%C3%A9vy_process" rel="nofollow">inde... | g23385 | [
0.06878729909658432,
-0.05478593334555626,
0.024584921076893806,
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0.029936591163277626,
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0.012591094709932804,
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0.01987631991505623,
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... |
<p>We know of the fact that zero correlation does not imply independence. I am interested in whether a non-zero correlation implies dependence - i.e. if $\text{Corr}(X,Y)\ne0$ for some random variables $X$ and $Y$, can we say in general that $f_{X,Y}(x,y) \ne f_X(x) f_Y(y)$?</p> | g35104 | [
-0.006581813562661409,
0.004544897936284542,
0.0374307744204998,
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0.0190133024007082,
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-0.01871372014284134,
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0.03... |
<p>In logistic regression, depending on the sign of the coefficient we can say, for example, that when predicting political interest, a coefficient of $1.226$ for following the news indicates that people are more likely to be interested in politics when they are following the news. However, can we say that based on thi... | g23386 | [
-0.03515109792351723,
0.02536098100244999,
0.02388625219464302,
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0.06505231559276581,
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-0.07203749567270279,
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0.050884000957012177,
0.05824152007699013,
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<p>I am trying to train a predictive model on whether a given person is ( male or female) based on behavior cues we've obtained from online surveys. </p>
<ol>
<li><p>The dependant variable will be a binary ( 1 or 0 ). </p></li>
<li><p>For the training data set, I have a list of 150+ numeric variables ranging from is... | g21831 | [
-0.025458339601755142,
0.0056277085095644,
0.010870562866330147,
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0.011117920279502869,
0.0... |
<p>Assume that $X$ is a zero mean random variable and $a$ and $b$ are constants. Show that if $Y = aX + b$ for some $a > 0$ than correlation $(X,Y) = 1$.</p> | g65005 | [
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<p>I am conducting a study in which I want to follow a group of subjects over time. My outcome of interest is continuous and I will measure it at 4 time points. I am trying to calculate the sample size necessary but all The sample size formulae i am finding involve two or more groups. The only table I found for a one g... | g65006 | [
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0.007360092364251614,
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... |
<p>I am running a model (logistic regression) with 20 independent variables in R. </p>
<p>Before running the model I calculated the correlation between all the variables and finally selected my variables by also checking "visually" the histograms of each variable in the case of presence and again in the case of absenc... | g23388 | [
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0.083... |
<p>I am using a powerful analytics tool built by Oracle (Data Miner).
I am trying to determine the probability of death for a patient given the presence of certain diagnosis codes. There will be up to 40 possible codes as column references (covariates) in the model.
Any reason why I must convert the presence indicator ... | g14882 | [
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0.007568382192403078,
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0.0... |
<p>I have around 800 companies for only two years period. However, around 200 of them have only one year observation. Is it still possible to conduct panel data analysis with such data
Thank you </p> | g65007 | [
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0.03471405431628227,
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0... |
<p>Actually, I wanted to ask you how can I define the terminating condition for gradient descent. </p>
<p>Can I stop it based upon the number of iterations, i.e. considering parameter values for, say, 100 iterations?</p>
<p>Or should I wait such that the different in the two parameters values 'new' and 'old' is very ... | g23396 | [
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0.006152135785669088,
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0.04198692739009857,
0.017076121643185616,
0.07... |
<p>Suppose we have two independent Poisson-distributed variables $X_1$ and $X_2$. We want to test whether the Poisson parameters are equal, i.e. whether $\lambda_1=\lambda_2$. </p>
<p>Now we have 4 distinct statistical <em>exact</em> tests to choose:</p>
<ol>
<li>E-test (see Krishnamoorthy and Thomson, <a href="http:... | g23398 | [
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<p>Hello to all the biostatisticians and epidemiologists out there,</p>
<p>I have looked up and down for a standard definition of recurrence-free survival, and the issue I'm having is determining if the standard includes DEATH as an event or not. I have seen some studies censor at death and others include death along... | g23399 | [
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<p>I have several groups of data for time series analysis, and I need some automatic way to do the analysis. I try to find a way in SAS to automatically do the job, but I can't find one corresponding to <code>auto.arima()</code> in R. </p>
<p>I have two questions regarding this:</p>
<ol>
<li><p>The closest one is to ... | g65008 | [
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0.008042432367801666,
0.011290686205029488,
0.03664851188659668,
0.04353722557425499,
0.... |
<p><strong>Please note that I also posted this same question in an SPSS specific forum, however if anyone here can also help, I would appreciate it.</strong></p>
<p>I have a question regarding repeating time-to-events measurements and after a quick search I really did not find anything that directly answered my questi... | g23400 | [
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<p>0 down vote favorite
1</p>
<p>I used nftool in Matlab 2012 and trained a network. I gave the training inputs as x=[250:1] and targets as t=[250:1]. I used 10 hidden layers. I trained the network and got the results and exported the data to workspace. I finally got net as the variable in the workspace. I want to rea... | g65009 | [
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0.0018235337920486927,
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-0.00752489222213625... |
<p>The kurtosis is to measure the peakedness and flatness of a distribution. The density function of the distribution, if it exists, can be viewed as a curve, and has geometric features (such as curvature, convexity, ...) related to its shape.</p>
<p>So I wonder whether the kurtosis of a distribution is related to so... | g65010 | [
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<p>The definition of a sufficient statistic is: Let $X_1,...,X_n$ be a random sample from a distribution indexed by a parameter $\theta$. Let $T$ be a statistic. Suppose that, for every $\theta$ and every possible value $t$ of $T$, the conditional joint distribution of $X_1,...,X_n$ given that $T=t$ depends only on $t$... | g65011 | [
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<p>I want to use log likelihood formula to relate between two items.</p>
<p>The formula is:</p>
<pre><code>LLR = 2 sum(k) (H(k) - H(rowSums(k)) - H(colSums(k)))
</code></pre>
<p>When this is the table:</p>
<blockquote>
<p>...............................|<strong>Event
A............................</strong>|<stro... | g23407 | [
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0.0014912603655830026,
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0.01... |
<p>My aim is to detect a malware by testing it with the extracted features. I have extracted the binary features of 150 malware and 150 benign files by using the hex editor tool for unpacking the files and net beans for generating a dataset into an Excel sheet.</p>
<p>Now I have features of malware and benign datasets... | g65012 | [
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0.034070346504449844,
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0.035567838698625565,
0.03170182183384895,
0.05984131246805191,
0.052... |
<p>I would like to check my understanding of the Chow Forecast test.The test is used to perform a test on the following models: $y_1=\beta X+\epsilon_1$ and $y_2=\beta X+ \nu + \epsilon_2$, with $H_0:\nu=0$ and $H_1: \nu\neq 0$. </p>
<p>Now I wonder whether that means that the following holds true:
\begin{align*}
F&am... | g65013 | [
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0... |
<p>I have a bivariate set of data points which I want to fit to a self-defined distribution (i.e. not standard normal or chi-square or like that, a different, let's say "new" density function). I would wish to fit it via method of maximum likelihood, but my density function has 2 infinite sums in it so strictly speaki... | g65014 | [
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0.004172678105533123,
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0... |
<p>Does anyone know how the values on the z-score table are created, either with R code or anything else?</p>
<p>thank you</p> | g49715 | [
-0.004080324433743954,
0.002660015132278204,
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0.0015658173942938447,
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0.004602622240781784,
0.05088431388139725,
0.0... |
<p>Suppose we have an estimator $\hat{f}(Y_1, \cdots, Y_n)(t)$ for the fixed design nonparametric regression model:</p>
<p>$$
Y_i = f(\frac{i}{n}) + \epsilon_i, \; f \in L^p[0,1].
$$</p>
<p>The estimator at hand might have very good theoretical properties (e.g. achieves certain oracular risk up to a multiplicative fa... | g23410 | [
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... |
<p>I am wondering about how to interpret the coef_ variable in the logistic regression class of sklearn. Given a dataset with m features and n categories, coef_ seems to be a matrix with the size of (n-1, m) -- In Python, it is a list (size n-1) of a list (size m). </p>
<p>In 2 category classification (i.e., the used ... | g23415 | [
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<p>I'm working through a homework assignment and I'm having an inordinately difficult time trying to calculate the MSE of two different estimators. The homework is described as this:
Let $X$ and $Y$ be random variables with joint density:</p>
<p>$p(x,y) = 2$ if $x\in A$</p>
<p>It is $0$ otherwise.</p>
<p>$A$ is a s... | g65015 | [
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<p>I have tried to understand the differences. Just to be clear, I <em>think</em> I understand the two sources of variation in prediction comes from the variation in the distribution of the <em>location</em> of Y and <em>within</em> variation of Y. The thing I do not get is, <em>why</em> we do not use the estimate of t... | g25931 | [
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<p>In a multiple linear regression with highly correlated regressors, what is the best strategy to use? Is it a legitimate approach to add the product of all the correlated regressors?</p> | g49710 | [
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0.004483690485358238,
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-0.05282359570264816,
0.0022341860458254814,
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... |
<p>I would like to apply KDE to inventory replenishment, but I am not sure how to use the analysis to predict future sales based on past sales. Given a set of data and having applied KDE to it (probably using a Gaussian distribution), how do I make a prediction about the future? </p>
<p>Thanks for any help! Please let... | g65016 | [
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<p>This should be a relatively simple question. I'm trying to confirm my understanding of the subscript notation on expectations when the subscript denotes a conditioning. In the example
$$E_{Y|X}[(Y-f(X))^2|X]$$
the subscript denotes the distribution over which you take the expectation, so we would want to use $p_{Y... | g65017 | [
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<p>My dependent variable is categorical (with 3 levels) and my predictor variables are a mix of continuous (age in months, test 1 score, test 2 score, test 3 score) and categorical (gender). I believe I should run a multinomial regression, but when I do the results are really uninterpretable because each age is basical... | g65018 | [
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<p>I would like to know if the following analysis strategy is correct conceptually, if it makes sense. I found difference in fish assemblage structure between two estuarine sectors, through PERMANOVA. I would like to identify what environmental factors are associated with this difference. Then, I used DISTLM (Distance‐... | g65019 | [
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<p>I am having some issues with the derivation of the equation of ridge regression</p>
<p>I know the part without the regularization param like</p>
<p>$\beta = (X^TX)^{-1}X^Ty$</p>
<p>But after adding the L2 term $\lambda||\beta||_2^2$ how come the solution is </p>
<p>$\beta = (X^TX + \lambda I)^{-1}X^Ty$</p>
<p>I... | g65020 | [
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0.01613... |
<p>I have a data set with the following:</p>
<p>N = 60;
x = developmental stage (range 25 to 44);
y = proportion of 10 minute trial performing a behavior (range 0 to 0.81; 30 zeros)</p>
<p>A scatterplot produces a quadratic looking curve where those in mid-development clearly performed the behavior for more time. Mos... | g65021 | [
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<p>I am trying to create the formula object for <code>coxph()</code> manually, as I want to reproduce it in <a href="http://rubygems.org/gems/rsruby" rel="nofollow">RSRuby</a>. Note that the response variable needs to be a <code>Surv</code> object, the output of the <code>Surv()</code> method. The <code>Surv</code> obj... | g65022 | [
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<blockquote>
<p><strong>Possible Duplicate:</strong><br>
<a href="http://stats.stackexchange.com/questions/33547/how-does-the-standard-error-work">How does the standard error work?</a> </p>
</blockquote>
<p>Let's say I have an unbiased estimator, which is the sample mean, to estimate $\theta$. When can you say ... | g49399 | [
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<p>For a long time now, I have been thinking about working with neural networks and genetic algorithms. I have never been able to decide whether it makes sense to start writing my own code, or to reuse the many, many options made by others.</p>
<p>In my experience, assuming the programmer knows what he or she is doin... | g23424 | [
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0.0271... |
<p>There exist an image dataset referred to as <a href="http://www1.cs.columbia.edu/CAVE/publications/pdfs/Nene_TR96.pdf" rel="nofollow">COIL-20</a>. There are several paper that describes different dimensionality reduction methods and apply them to produce a 2d plot of this dataset. These pictures often contain one or... | g23425 | [
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<p>I've been wondering about this one for a while; I find it a little weird how abruptly it happens. Basically, why do we need just three uniforms for $Z_n$ to smooth out like it does? And why does the smoothing-out happen so relatively quickly?</p>
<p>$Z_2$:</p>
<p><img src="http://i.imgur.com/ER5qI.gif" alt="2"> </... | g65023 | [
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<p>There are two Boolean vectors, which contain 0 and 1 only. If I calculate the Pearson or Spearman correlation, are they meaningful or reasonable?</p> | g49727 | [
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<p>The <code>bild</code> package appears to be an excellent package for serial binary responses. But it is for discrete time. I would like to specify a smooth function of time for the odds ratio connection of the current response Y with binary responses measured at earlier times, or at least a first-order Markov vers... | g23426 | [
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<p>I am trying to solve the discriminant functions in R for two, 2-D gaussian distributions and trying to find the decision boundary.</p>
<p>The discriminant function is given by,</p>
<p>$g(x) = -.5x'\sigma^{-1}x + \sigma^{-1}\mu x$</p>
<p>where, $x'$ is $x$ transpose, $\mu$ is the mean and $\sigma$ is the covarianc... | g65024 | [
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0.009473210200667381,
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0.07849252969026566,
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<p>I used the following R script to calculate the Kappa and ICC for a measured done by two raters on 23 subjects:</p>
<pre><code>library(irr)
temp <- structure(list(value.x = c(10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 2, 10, 10, 2),
value.y = c(8, 8, 10, 10... | g43266 | [
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0.06274815648794174,
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0.0077481959015131,
0.024632494896650314,
0.0011833789758384228,
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0.008... |
<p>I have a small number of studies where the same model was calculated and want to infer the typical standard residual deviation. I have the degrees of freedom, the sum of the squares SSR and the mean of the square of the residuals MSR, but not the residuals themselves. My current plan is to do a bayesian meta analysi... | g46409 | [
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... |
<p>I was trying to understand the following result more intuitively (for linearly separable data):</p>
<p>$$ k \leq \frac{R^2}{\gamma_g^2}$$</p>
<p>where:</p>
<p>k = is the number of mistakes the perceptron algorithm does</p>
<p>R = is the distance at which the data points are confined to.</p>
<p>$\gamma_g = \text... | g23429 | [
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0.06166291981935501,
0.0764833316206932,
0.01... |
<p>I used randomForest to classify 6 animal behaviours (eg. Standing, Walking, Swimming etc.) based on 8 variables (different body postures and movement). </p>
<p>The MDSplot in the randomForest package gives me this output and have problems interpreting the result. I did a PCA on the same data and got a nice seperati... | g65025 | [
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-0.08917036652565002,
0.03073301538825035,
0.03853201866149902,
0.032235994935035706,
-0.01... |
<p>I have a GLM and my explanatory variables are a factor of 9 levels (X1) and a numeric variable (X2).</p>
<p>If I have to report the formula:</p>
<p>$Y = B_0 + B_1X_1 + B_2X_2$</p>
<p>I have 1 coefficient for the intercept and 1 coefficient for the numeric variable, that's ok, but I have 8 coefficients for the fac... | g65026 | [
0.0016262048156931996,
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0.0664340928196907,
0.031266387552022934,
0.0... |
<p>With the K Clusters generated using K Means Clustering, how do we calculate the density of each cluster? Is there any formula for it?</p> | g65027 | [
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... |
<p>I have finance data that I need to forecast out for 7 years. My data is generally debits and credits, and those are split into a number of sub-series which share common traits (e.g. similar seasonality and/or trend).</p>
<p>My question is, is it appropriate to </p>
<ol>
<li>split the total series into component p... | g65028 | [
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0.024096066132187843,
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-0.0... |
<p>I have a set of data, which, from an initial test, is expected to be non-normal. My initial test shows a cluster of data gathered around 90, and another cluster gathered around 120. Neither cluster looks particularly normal either (but they both contain a very small amount of values, so it's hard to tell if they fol... | g65029 | [
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0.009637790732085705,
0.010291555896401405,
-0.0... |
<p>I have a dataset of two patient and one healthy control group which I would like to compare (using R) with respect to a continuous outcome variable (each subjects is measured once). However the groups differ in age. In the context of the dataset the age effect is not of interest. My questions are:</p>
<ul>
<li><p>W... | g47068 | [
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0.02553587220609188,
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0.0622885599732399,
0.0004727774066850543,
0.013969827443361282,
0... |
<p>In field of economics (I think) we have ARIMA and GARCH for regularly spaced time series and Poisson, Hawkes for modeling point processes, so how about attempts for modeling irregularly (unevenly) spaced time series - are there (at least) any common practices?</p>
<p>(If you have some knowledge in this topic you c... | g65030 | [
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0.015596088953316212,
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... |
<p>I have over 200 datapoints in my set and I have related my predictors (mostly categorical) to a single continuous response variable in a multiple regression model. The model is to my satisfaction, and now I need help in analyzing one aspect of it.</p>
<p>In my case, each datapoint represents an event, and my respon... | g65031 | [
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... |
<p><a href="http://www.stat.columbia.edu/~gelman/arm/" rel="nofollow">Gelman and Hill 2007</a> present a varying using WinBUGS and R:</p>
<p>Simplifying the data description hugely, the data is from 85 counties,
with log radon level measured in the basement and the first floor of houses in
these counties (multiple h... | g43276 | [
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0.04892028495669365,
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0... |
<p>I'm trying the functions to check the cointegration of a matrix.</p>
<p>I'm using <strong>Phillips & Ouliaris Cointegration Test</strong></p>
<p>The function in <em>tseries</em> package is <strong>po.test</strong> and <strong>ca.po</strong> in <em>urca</em> </p>
<p>The results with <strong>urca</strong> are:<... | g23431 | [
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0.0467715747654438,
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0.05225393921136856,
0.0183996744453907,
-0.07337... |
<p>Let's say that there are a series of physical objects each with properties (round, red, soft, etc.) and each property affects the value of the object. Certain combinations can affect the value as well (round and red are valuable when found together, but not separate).</p>
<p>Given a large list of objects and values... | g65032 | [
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-0.024893643334507942,
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0.006378264632076025,
0.07228747010231018,
0... |
<p>Is it appropriate to do a logistic regression where both the dependent and independent variables are binary? for example the dependent variable is 0 and 1 and the predictors are contrast coded variables -1 and 1 ?</p> | g37680 | [
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... |
<h3>Context:</h3>
<p>I ran 3 experiments comparing in each 2 techniques. In each experiment participants had simply to express a preference about which of the 2 techniques they thought was clearest to understand.</p>
<p>30 participants were involved, 10 in each experiment.
No repeated measures were involved.</p>
<p>... | g38116 | [
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0.02309158444404602,
0.03476424887776375,
0.03203285112977028,
0.02109387330710888,
0.028719... |
<p>I have fitted a model using proc reg, say, using this</p>
<pre><code>proc reg data = mydata;
model a = b;
run;
</code></pre>
<p>But in this particular application it is better to over-estimate than it is to under-estimate. So I actually want to refit this model this time using the residuals as weights so they an... | g65033 | [
0.029755469411611557,
-0.017847608774900436,
-0.02066045254468918,
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-0.01377265527844429,
0.03561856225132942,
0.04165497422218323,
0.02... |
<p>Can observation be used to collect data for hypothesis testing? Can we be confident with the power of the test in those cases?
We know power of the test can be applied with hypothesis testing for data collected through sample.</p> | g23433 | [
0.04270648956298828,
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0.009096836671233177,
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-0.024764686822891235,
0.09936675429344177,
0.0091631431132555,
0.012035719119012356,
0.... |
<p>I found out that my panel data 'suffers' from heteroscedasticity by doing the test described on Stata FAQ, <a href="http://www.stata.com/support/faqs/statistics/panel-level-heteroskedasticity-and-autocorrelation/" rel="nofollow">Testing for panel-level heteroskedasticity and autocorrelation</a>. I understand that t... | g65034 | [
0.03859826922416687,
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0.04432... |
<p><strong>Background:</strong> I am a stakeholder in a research project involving seed germination and viability tests for a number of shrub species. The ultimate goals of this project are to determine best practices for future storage and use of these species' seed. To investigate this, seeds from a variety of access... | g20867 | [
-0.01789912022650242,
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-0.014000854454934597,
0.0012431970098987222,
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0.015791209414601326,
0.013246056623756886,
0.008160942234098911,
0.035241227596998215,
-0.02... |
<p>I have two density functions: $h_{1}(x)$, $h_{2}(x)$. </p>
<p>I want to estimate parameters from one dataset using $ h_{1} $ and $ h_{2} $ andthe GMM estimator or the GEL : from the article "Computing Generalized Method of Moments and Generalized Empirical Likelihood with R"</p>
<p>I want to estimate the parameter... | g23436 | [
-0.03530962020158768,
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-0.01040864922106266,
0.006830975878983736,
-0.017511842772364616,
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0.05795145407319069,
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0.03461360186338425,
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0.039526116102933884,
0.... |
<p>I have been trying to do code this:
For each $\left( x,z\right) \in\left( X,Z\right):$</p>
<p>$r(x,z)=\sum_{i=1}^{n}Y_{i}1\{X_{i}<=x\}1\left\{ Z_{i}<=z\right\}$</p>
<p>So far, the best way I came up to do this is by using a loop. Here an example:</p>
<pre><code>y=rnorm(10)
x=c(1,1,1,2,2,2,3,3,3,4)
z=c(5... | g65035 | [
0.014756389893591404,
0.025022417306900024,
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0.04335185885429382,
0.0438409186899662,
0.049... |
<p>Undirected Graphical Models are usually known as "Markov Networks" and Directed Graphical Models are known as "Bayesian Networks". This is naming is not very clear to me. It might be because of some historical background, though I am just curious to know if there is any concrete reason for this naming. </p> | g65036 | [
0.02431127242743969,
0.018228301778435707,
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0.02586965076625347,
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0.093388132750988,
0.013... |
<p>I am totally new to stats and the field of confidence intervals. So this might be very trivial or even sound stupid. I would appreciate if you could help me understand or point me to some literature/text/blog that explains this better.</p>
<p>I see on various news sites like CNN, Fox news, Politico etc about their ... | g65037 | [
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0.03941456601023674,
0.011422853916883469,
0.027646120637655258,
-0.0... |
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