question stringlengths 37 38.8k | group_id stringlengths 2 6 | sentence_embeddings listlengths 768 768 |
|---|---|---|
<p>The following process $X$ is generated as the sum of a structure $y$ and an $AR(1)$ process with $\phi=0.4$ and $\sigma_{\epsilon}^2=1$:</p>
<pre><code>N=200 # length of time series
t=1:N
A=20 # amplitude of the structure
y = rep(0,N)
a = 30
b = 170
y[a:b] = A * (t[a:b] - a)/ (b-a) # the structure (see the plot... | g62377 | [
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... |
<p>I am trying to find a simple algorithm to measure the probability of the proximity distance between location of randomly placed actual target and subject's guess of its location on an 8 x 8 grid (64 squares). I.e. if the guess is a MISS, what is the probability of the guessed location being located on any given squ... | g19422 | [
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<p>Are there any limitations for using Cohen's kappa with sparse data? I need inter-rater agreement between 2 raters for ~15 items, and the data in the contingency table is quite sparse (0 in some cells, lots of values < 5).</p> | g62378 | [
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<p>What is a good Python framework to use for statistical analysis using Bayes Nets.</p>
<p>The following statistical frameworks in one way or other do not support expected features. </p>
<p>Python Scikit does not have an implementation of Bayes Net.
Looked into other Python implementation such as:
Libpgm - not clea... | g19424 | [
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<p>So, I have a data set of percentages like so:</p>
<pre><code>100 / 10000 = 1% (0.01)
2 / 5 = 40% (0.4)
4 / 3 = 133% (1.3)
1000 / 2000 = 50% (0.5)
</code></pre>
<p>I want to find the standard deviation of the percentages, but weighted for their data volume. ie, the first and las... | g62379 | [
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<p>I have some survival data from which I compute the annual failure rates. The parameter in which I am interested is the mean failure rate. </p>
<p>Now I select certain subjects that have a given characteristic, so the sub-sample is not random. For example, I have very few subjects having the characteristic in the be... | g62380 | [
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<p>I've read that Kolmogorov-Smirnov test should not be used to test the goodness of fit of a distribution whose parameters have been estimated from the sample.</p>
<p>Does make sense to split my sample in two and use the first half for parameter estimation and the second one for KS-test?</p>
<p>Thanks in advance</p> | g62381 | [
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<p>Is there any known Bayesian, ML or MDL interpretation of cross-validation? Can I interpret cross validation as performing the right update on a specifically crafted prior?</p> | g3993 | [
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<p>I'm working with a large dataset consisting of just over 1 million cases. The data are longitudinal covering 14 years and hierarchical with about 500 of the level 2 units. Each case is a criminal sentence outcome (prison vs. no prison) and the level 2 units are the judges handling the cases. I'm trying to quantify... | g3994 | [
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<p><img src="http://i.stack.imgur.com/nLqEA.jpg" alt="enter image description here"></p>
<ul>
<li>Why are there negative values in the range of the plot? </li>
<li>How is the center of the plot (i.e., the $0.0$ point) found? </li>
<li>How did the black-brown points end up in the third quadrant of the plot? </li>
<l... | g49643 | [
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<p>Lets say I have a normal distribution of estimates (e) for a random variable (v). At some point an event occurs where the value of the variable becomes known (v). Now I want to find a new distribution where i calculate the distance of all estimates from the known value (|v-e|). Since this new distribution is bounded... | g49644 | [
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... |
<p>For non-statisticians like me, it is very difficult to capture the idea of <code>VI</code> metric (variation of information) even after reading the relevant paper by Marina Melia "<a href="http://www.sciencedirect.com/science/article/pii/S0047259X06002016" rel="nofollow">Comparing clusterings - An information based ... | g62382 | [
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<p>I have this matrix:</p>
<pre><code>habitats <- matrix(c(0.4,0.1,0.5, 0.2,0.6, 0.2), nrow = 3, ncol = 2,
dimnames = list(c("grassland","intertidal","saltmarsh"),
c("site1","site2")))
habitats
site1 site2
grassland 0.4 0.2
intertidal 0.1 0.6
saltm... | g62383 | [
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... |
<p>Imagine a long, horizontal, transparent acrylic tube which is marked with duct tape every 50 cm in such a way that you can distinguish 10 "sections" of the tube.</p>
<p>I want to study the movements of ants in these plastic tubes, which are under four combinations of two different conditions, namely each tube has d... | g62384 | [
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<p>I have a matrix that is of the shape <code>n_samples</code> by <code>n_features</code>, where <code>n_samples</code> ~ 7000 and <code>n_features</code> ~ 800. To clarify, <code>n_features</code> are categorical labels, each representing an amino acid position.</p>
<p>I'd like to know which columns have amino acid p... | g62385 | [
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... |
<p>I am new to SEM. I am analyzing a dataset with five constructs and 21 indicators. I found there could be two ways to run the structural model in AMOS. One is to include all the measured indicators in the model and the other one is to use the composites imputed by AMOS. Model fit of the model with indicators was poor... | g62386 | [
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<p>First let me describe the situation I'm dealing with:</p>
<p>I'm looking at performance data for a software system. I have data for many versions of the software, including ongoing. For each version I have a series of values for the run-times of tests run against it, usually about 20 (of the same test). These gener... | g19427 | [
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<p>I am about to do a laboratory experiment in the scientific field of soil ecology and hydrology. Beforehand I want to make sure not to make any crucial mistakes, and therefore I would appreciate any hints and comments from your side. The main issue is how to deal with high natural variability (~25%) and a rather smal... | g37620 | [
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<p>I have the following question:</p>
<blockquote>
<p>In a survey, a simple random sample of 1,000 households was drawn to
determine the distribution of household size in a city. Interviewers
were required to visit the house to carry out the survey. Interviewers
could only reach 653 households in the sample. T... | g19428 | [
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<p>When comparing the direction and magnitude of the difference between the original means and the adjusted means what does the change say about the covariate?</p>
<p>For example: IV = Grade, DV = Test Score, Covariate = IQ Score</p>
<p>Am I correct in assuming that if a group's <strong>adjusted mean</strong> is high... | g62387 | [
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<p>I have some census data of 20 urban regions. I want to use them to combine 5 criteria to determine which region is most deprived.
Is it acceptable to use factor analysis?</p> | g62388 | [
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<p>Given a function $f(\mu)$ (satisfying certain properties), it is possible to find a function $g(x)$ such that $f(\mu)=\int_{-\infty}^{\infty} g(x)\phi(x-\mu) dx $, where $\phi$ is the standard normal density. In fact, $g=\widehat{\widehat{f}/\widehat{\phi}}$, where hat denotes the Fourier transform (might be missing... | g62389 | [
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<p>Is there a rule of thumb? How much improvement in accuracy can I expect with extensive grid search? Can it be a HUGE difference?</p>
<p>Does this differ with different kernels? ( linear, polynomial, RBF? )</p>
<p>I am wondering whether it's something I should focus on ( I am using SVMLight so it's really hard to d... | g19430 | [
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<p>I am interested in comparing a non-linear model with up to 12 parameters to many datasets. However, each instance of the model takes a significant amount of time to compute (~1 hour), so I am pre-computing instances of the model for various parameter values and then comparing these to all the different datasets.</p>... | g37661 | [
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<p>I want to integrate user input into clustering algorithm. So that users can control which docs should be in the same cluster. What are some ways to achieve this? Can metric learning do this? </p> | g62390 | [
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<p>I'm relatively new to bayesian statistics and have been using JAGS recently to build hierarchical bayesian models on different datasets. While I'm very satisfied of the results (compared to standard glm models), I need to explain to non-statisticians what the difference with standard statistical models is. Especiall... | g19432 | [
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<p>Consider $\sum_{i=1}^N |X_i|$
where $X_1, \ldots, X_N$ are i.i.d. and the CLT holds.<br>
How many of the biggest terms add up to half the total sum ?<br>
For example, 10 + 9 + 8 $\approx$ (10 + 9 + 8 $\dots$ + 1) / 2:
30 % of the terms reach about half the total.</p>
<p>Define<br>
$ \qquad\text{sumbiggest( j}; X_... | g37614 | [
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<p>Lets assume we only have 2 variables, <code>x</code> and <code>y</code>, and our model (in R code) is <code>lm(y~x)</code>. Given that any 2 points can be used to form a line, I know it doesn't make much sense to try to fit this model if I only have 2 observations.</p>
<p>What about the case where I have 3 observa... | g62391 | [
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... |
<p>I am comparing two power functions in R, a base function <code>stats::power.prop.test</code>, and the function <code>pwr::power.2p.test</code> in the <code>pwr</code> package.</p>
<p>I would think that they would give the same answer, but they are slightly different. And the equations being solved in the source cod... | g62392 | [
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<p>I have two positively correlated variables, Q95 (independent, 95-percentile flow in cumecs from the previous summer) and LIFE (dependent, a score describing the health of some invertebrates). I would like to be able to predict, to some degree of confidence, what value of Q95 is required to attain a given LIFE. From ... | g38467 | [
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<p>I'm currently stuck on this data, trying to figure out what test is needed. I started thinking it needed an ANOVA test but on reading, figured it was a Chi Squared test. On more reading, that doesn't seem right either.</p>
<p>The data I have is in a table as such:</p>
<pre><code>Damage Group 0 minutes 2 min... | g38468 | [
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<p>I am interested in knowing whether or not there is a consensus about the optimal way to analyze hospital length of stay (LOS) data from a RCT. This is typically a very right-skewed distribution, whereby most patients are discharged within a few days to a week, but the rest of the patients have quite unpredictable (a... | g19435 | [
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<p>I have started looking into robust methods of data analysis. In particular, robust regression methods for ANCOVA type models using the <em>"lmRob"</em> function from the <em>"robust"</em> library in R. I'm having a hard time finding what assumptions I need to satisfy in order to use this. I've read that they can be ... | g19436 | [
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<p>I hope this is the right place to post this, I considered posting it on skeptics, but I figure they'd just say the study was statistically wrong. I'm curious about the flip side of the question which is how to do it right.</p>
<p>On the website <a href="http://quantifiedself.com/2009/10/the-false-god-of-coffee/">Qu... | g62393 | [
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<p>I have done some AI projects involving inference, neural networks, etc., but I'm not sure what the right algorithm would be for this problem.</p>
<ul>
<li><p>Say there is a set of pills, where each type is visually unique. So, for example, a pain reliever might be a red pill and an allergy medication might be a blu... | g38155 | [
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<p>Could anyone advise if the following makes sense:</p>
<p>I am dealing with an ordinary linear model with 4 predictors. I am in two minds whether to drop the least significant term. It's $p$-value is a little over 0.05. I have argued in favor of dropping it along these lines:
Multiplying the estimate of this term by... | g19439 | [
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<p>Let's say you have a large random sample of soccer players in Europe but you are only interested in what happens in Spain. Could you reduce your sample to players in Spain and still call it a random sample (but of a different population)?
If not, how would you call that subsample and which specific precautions shoul... | g19440 | [
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<p>If I have two (Pearson) correlation coefficients between Variables A and B (for example .657 for males and .876 for females) and I want to test if there is a difference based on gender (as in this case), which of the following phrases should I use to describe this process?</p>
<ul>
<li>Test for equality of the corr... | g19441 | [
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<p>I have a univariate time series which is an index of susceptibility to failure, and a binary variable which indicates whether a failure actually occurred in a given time window or not. I want to carry out a statistical test that would quantify the performance of the susceptibility index (e.g., compared to a null mod... | g62394 | [
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<p>In a paper I've written I model the random variables $X+Y$ and $X-Y$ rather than $X$ and $Y$ to effectively remove the problems that arise when $X$ and $Y$ are highly correlated and have equal variance (as they are in my application). The referees want me to give a reference. I could easily prove it, but being an ap... | g62395 | [
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<p>Can anybody explain in detail:</p>
<ol>
<li>What does reject inferencing mean?</li>
<li>How can it be used to increase accuracy of my model?</li>
</ol>
<p>I do have idea of reject inferencing in credit card application but struggling with the thought of using it to increase the accuracy of my model.</p> | g62396 | [
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<p>I have learnt that using <code>vif()</code> method of <code>car</code> package, we can compute the degree of multicollinearity of inputs in a model. From <a href="http://en.wikipedia.org/wiki/Variance_inflation_factor">wikipedia</a>, if the <code>vif</code> value is greater than <code>5</code> then we can consider t... | g62397 | [
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<p>I just found out how to run a R script from the R Console under Windows. </p>
<pre><code>source("arrrFile.R")
</code></pre>
<p>The problem is, this command runs "silently".
How can I run the file command-by-command as I would type it in the console? </p> | g39705 | [
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<p>when integrating a function or in complex simulations, I have seen the Monte Carlo method is widely used. I'm asking myself why one doesn't generate a grid of points to integrate a function instead of drawing random points. Wouldn't that bring more exact results?</p> | g62398 | [
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<p>Is it important to scale all the features into a common range (normalized) when using random forests (bagging) in classification. Or can random forests handle features in different ranges without problems (bias to the larger values). Some features may have a value in the 1000-range and others in the 0-1 range. </p> | g62399 | [
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<p><strong>EDIT:</strong>
<em>OK, having spent the last couple of hours checking out some pubs on functional data analysis, I am actually starting to feel a little silly having asked the question in the first place! It's becoming obvious (well. Still a tad -ish but getting there.) - Thanks, @PeterFlom for pointing it o... | g62400 | [
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<p>Is there a way to return a matrix of means for levels of a factor using <code>effect()</code> in R? I see if you simply call an effect object you get the values printed, but I would like a matrix of these values that can be operated on. You can do this for the lower and upper confidence intervals like this:</p>
<pr... | g62401 | [
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<p>Imagine the following scenario: You have an urn with $r$ red balls and $b$ blue balls. The red balls have two hooks, the blue balls have one hook. Consequently, if $r=1$ and $b=1$, you would be twice as likely to fish a red ball rather than a blue ball. </p>
<p>What is the expected fraction of blue balls that you f... | g62402 | [
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<p>Given a joint pdf for 3 random variables (X1, X2, X3) I´ve applied a transformation (Y1, Y2, Y3) and found the joint pdf for the transformed variables. This joint pdf´s domain is 0 < Y1 < Y2 < Y3 < 1. The thing is, I can´t marginalize out enough variables in order to find the marginal pdf for each of the... | g16172 | [
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<p>I've been taught that binning a continuous variable into categories is almost never a good idea, because you lose information in the process. But now I'm facing a situation where I have an age variable that is "mostly continuous", which is to say that about 90% of the values represent age in years, and the remaining... | g37646 | [
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<p><img src="http://i.stack.imgur.com/rmT9d.png" alt="enter image description here"></p>
<p>(a)how can be r/(n+1)? in my lecture notes, Dist. of r-th order statistics is <img src="http://i.stack.imgur.com/sYgFi.png" alt="enter image description here"></p>
<p>but i can't figure out how to come out (a) from this equati... | g62403 | [
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<p>I have a sequence of Bayesian Networks for del with more epochs. For example if i work with trafic on street I can have a BN for morning, one for afternoon e one for evening.</p>
<p>If i collect data for 24h, when end the morning and start the afternoon ? when end the afternoon and start the evening? when end the e... | g62404 | [
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<p>Could you help me prove that For N(θ,1) density, Rao's Score Test is equivalent to UMPU test?</p> | g19448 | [
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<p>If I understand correctly in order to calculate a centroid in PCA I can calculate the mean of X points and Y points (e.g., PC1 and PC2).</p>
<p>When I run a simple PCA (code below) I don’t get the centroid of each group (species). Unfortunately, I do not know how to continue from this point as I am new in R. Theref... | g62405 | [
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<p>This question is similar to</p>
<p><a href="https://stats.stackexchange.com/questions/54498/does-every-log-linear-model-have-a-perfectly-equivalent-logistic-regression">Does every log-linear model have a perfectly equivalent logistic regression?</a></p>
<p>but my problem is understanding the proof.Every proof is v... | g62406 | [
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<p>I'm trying to work around the randomForest package limit of 32 levels for factors. </p>
<p>I have a data set with 100 factors in one of the variables. </p>
<p>I wrote the following code to see what things would look like using sampling WITH replacement and how many tries it would take to get certain % of factors... | g19452 | [
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<p>Any help would be greatly appreciated.</p> | g62407 | [
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<p><strong>Comment:</strong> heavily edited, both to clarify and to fix a mistake. First 7 comments below refer to the previous version.</p>
<p>I have an experiment where 3 raters go over the same data 2 times each, trying to make a diagnosis. The second of these two passes serves as the gold standard, and I want to c... | g38500 | [
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<p>This may be an elementary question which is why I have not been able to find it on Stackexchange or Mathoverflow however I am having problems with the arithmetic involved in updating likelihoods using Bayes theorem for a problem I am working on.</p>
<p><strong>Background:</strong> </p>
<p>I am attempting to give l... | g62408 | [
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<p>I have located references that indicate that a 1-sided confidence band is equivalent to the 95% 2-sided confidence band on a linear regression. Does this equivalence hold true for prediction intervals over a linear regression model?</p>
<p>Example:
Given a set of data with a random sampling of age vs strength valu... | g597 | [
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<p>I want to perform a number of univariate regressions with different symptoms (e.g. fever, cough, sneezing) as the response variable and one categorical variable (which is always the same each time) as an explanatory variable - age group (0-4, 5-14, 15-64, 65+). In total there are 18 symptoms so hence, I want to do 1... | g62409 | [
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<p>Say I want to do a logistic regression on whether it snows on a given month of the year and day of the week. I'd have 12 months and 7 days. My understanding is that this would translate into 17 dummies (11 for months and 6 for days). </p>
<p>First off is this correct? Second, how would I interpret regression re... | g19458 | [
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0.11333571374416351,
... |
<p>If I am correct, the linear regression model is said to be a model where the response is linear in the parameters. That allows the response to be nonlinear in the predictor variables.</p>
<p>I was wondering if there is a name for the model where the response is linear in both the parameters and in the predictor var... | g49491 | [
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<p>Please excuse me if my question is dumb but I am not a Statistics student.
I have a project where I was exploring options for time series analysis where I found some papers on cointegration.
I have 4 variables. One of them response variable. I wanted to to the forecasting using the cointegration technique.... | g38506 | [
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<p>I fitted a linear mixed model with R as follows.</p>
<pre><code>lmme3cs = lme(LAZ ~ group_k + x1 + x2 + x4 + x6 + x1_k + x2_k + x4_k + x6_k, random = ~1|SECTORID/CHILDUID,
correlation = corCompSymm(form = ~1|SECTORID/CHILDUID),data=dat2c)
</code></pre>
<p>It has 50043 observations, but the object 'lmme3cs$... | g62410 | [
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<p>I am doing a lexical study, identifying personality factor structure of the Malay language adjectives.</p>
<p>I have three datasets:
1) The Malay adjective checklist
2) The Big-Five Mini Marker scale
3) The 60 items HEXACO PI</p>
<p>I have 589 respondents who attempted all three checklist and inventories</p>
<p>M... | g19466 | [
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<p>Could someone maybe give an explanation and formulas in terms of sums or matrix operations for the calculation of variance based effects, and total effect indices?</p>
<p>The information given on wikipedia: <a href="http://en.wikipedia.org/wiki/Variance-based_sensitivity_analysis" rel="nofollow">http://en.wikipedia... | g19467 | [
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<p>I am doing a project in which I need to estimate Weibull parameters for car part failures (I know the data follow Weibull). I have data for 1000 cars (part failure data). Now the problem is suppose some part fails after 6 years (from date of manufacturing) . But I have data for only the first three years. Now in thr... | g62411 | [
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<p>We are making algorithm for prediction of Conversion Rate (CR) for CPC advertising.</p>
<p>We have historical (statistical) data that we can analyze in many projections (in many factors).</p>
<p>For example we have such independent variables (factors, projections) as: </p>
<ol>
<li>keyword</li>
<li>date</li>
<li... | g62412 | [
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<p>I am currently in the process of trying to work out a ranking system for players using a dataset of players within the English Premier League. I have a number of statistics to work with but have decided that the following are the ones I want to use: </p>
<ul>
<li>Minutes</li>
<li>Pass %</li>
<li>Goals</li>
<li>Sho... | g19469 | [
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<p>I have this problem and I'd like some pointers to a "standard" method of solving this issue.</p>
<p>I have two time series, with points taken at the same time for each one of them; series A is a poll, of which I know the sample size (and therefore its variance); series B can't be defined with precision: it's a numb... | g62413 | [
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<p>I have two different set of features for which I have a SVM classifier and a Naive Bayes classifier, respectively. If I wanted to combine these two classifiers to get a better prediction, what option do I have?</p> | g62414 | [
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<p>I'd like to use Bayesian updating to form price expectations to be used in another model. I'm very new to this area, so your help would be highly appreciated. </p>
<p>I'm not sure which distribution to use for the prior. When I use normal distribution, I do not get much variability between prior and posterior. Howe... | g19471 | [
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<p>I'm trying to figure out why there is a difference when I run <code>anova(model1, model2)</code>
versus <code>anova(model2, model1)</code> in R. I know which model is nested within the other, but haven't been able to find in the documentation what the difference in syntax is actually doing.</p>
<p>In fact, this is ... | g19473 | [
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<p>I am hoping someone can help with the following: </p>
<ol>
<li><p>I have been trying to use the ltm package in R to get person fit estimates using a 3PL model. The problem I have been having is that I start off with 4947 response patterns (dichotomous) but when I run <code>tpm()</code> I end up with 4851 ability ... | g34449 | [
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<p>It's clear for me to count correlation and regression between two variables, e.g. X and Y.
Assume, that X is a fuel consumption and Y is engine displacement. I've got a data set with 100 pairs X Y, and based on those I can calculate a correlation rate between X and Y which in this case is obvious. So I'm trying to f... | g19477 | [
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... |
<p>I have a data that looks like this</p>
<pre><code> City Sex Rater drink response
1 NY M 1 coke 77
2 NY M 2 coke 72
3 NY F 3 coke 78
...
</code></pre>
<p>There are 3 different cities and 3 different types of drinks, and n=48.</p>
<p>How should I do ANOVA on... | g19480 | [
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0... |
<p>I am trying to estimate covariance components from PROC MIXED and having trouble with convergence problems in the REML approach when I use the NOBOUNDS option. Let me explain why I am using NOBOUNDS in case this is the problem.</p>
<p>I am trying to estimate genetic covariances among 12 traits in a group of self-fe... | g19483 | [
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<p>The question I want to ask is this: how does the proportion of samples within 1 SD of the mean of a normal distribution vary as the number of variates increases?</p>
<p>(Almost) everyone knows that in a 1 dimensional normal distribution, 68% of samples can be found within 1 standard deviation of the mean. What abou... | g19484 | [
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<p>I have a set of positive and negative samples in 2D $(x, y)$, and I would like to fit a curve $f$ to this data set so that $f(x, y_c)$ is increasing in $x$ and $f(x_c, y)$ is increasing in $y$. The function $f(x, y)$ can be thought of as the probability that a new random sample from point $(x, y)$ is positive. The f... | g62415 | [
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<p>I am implementing Newey West covariance matrix in code and wanted to know if anybody knows the matrix definitions and how the lags matrix is defined.</p>
<p>I not sure how to type equations here but the formula I am looking at is on page 53 Chac in this link <a href="http://math.uncc.edu/~zcai/KSU-reading-II.pdf" r... | g46090 | [
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<p>In case of robust estimators, What does <strong>Gaussian efficiency</strong> means? For example $Q_{_n}$ has 82% Gaussian efficiency and 50% breakdown point.</p>
<p>The reference is: Rousseeuw P.J., and Croux, C. (1993). “Alternatives to median absolute deviation.” J. American Statistical Assoc., 88, 1273-1283</p> | g62416 | [
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<p>I want to do a regression where my dependent variable has four categories <code>(1,2,3,4)</code> which represents the number of dependents. Can I do this with logistic regression? I read somewhere that <code>link=glogit</code> option is useful in this, can somebody please shed some light? I am new to this.</p>
<p>W... | g62417 | [
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<p>Suppose I have a large population of data points $(x,y)$ and that the Pearson's correlation is </p>
<p>$$\textrm{corr}(X,Y) = \rho$$</p>
<p>What can I reasonably say about the correlation I expect to observe in a sample of size $n$? If the sample correlation is $\rho_s$, roughly what is the spread is $\rho_s$? I... | g19492 | [
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<p><strong>Proposed Method:</strong></p>
<p>Given a time series $x_i$, I want to compute a weighted moving average with an averaging window of $N$ points, where the weightings favour more recent values over older values.</p>
<p>In choosing the weights, I am using the familiar fact that a geometric series converges to... | g62418 | [
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<p>Can you recommend a text mining package in R that can be used against large volumes of data?<br>
Secondly, is there a GUI available for any of the text mining packages in R?<br>
Thirdly, is there another open source text mining program that is easy and intuitive to use?</p> | g62419 | [
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... |
<p>With respect to a classification problem, I once heard the following comment:</p>
<p>Adding more positive training cases can increase the recall; and adding more negative training cases can increase the precision.</p>
<p>Is this comment correct? And what is the underlying logic if it is correct?</p> | g62420 | [
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<p>Wooldridge (Intro Econometric book) he states that seasonal dummy variables (say a dummy for the calendar month) satisfy the strict exogeneity assumption because "they follow a deterministic pattern. For example, the months do not change based upon whether the explanatory variables or the dependent variable changes ... | g62421 | [
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<p>I have completed Factor Analysis using Varimax rotation model as shown below. I need to be able to interpret/explain the below findings using factor loading with an absolute value of 0.40 or greater. Can somebody help me explain the below findings?</p>
<pre><code>Component Initial Eigenvalues Rotation Sums of Squ... | g62422 | [
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0.05081493407487869,
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<p>In their great book "Wavelet methods for time series analysis" (2006), Percival & Walden state on p. 83 that the first-round pyramid algorithm scaling filter coefficients</p>
<p>$\tilde{V}_{i,t}$</p>
<p>can be approximated by</p>
<p>$\frac{1}{N} \sum_{k=-\frac{N}{4}+1}^{\frac{N}{4}}{\chi_{k}e^{i 2 \pi t k/N}}... | g62423 | [
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0.03320734202861786,
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0.042590413242578506,
0.017203297466039658,
0.0206... |
<p>How should I define a model formula in R, when one (or more) exact linear restrictions binding the coefficients is available. As an example, say that you know that b1 = 2*b0 in a simple linear regression model. </p>
<p>Thank you!</p> | g38533 | [
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<p>A physics application I'm using reports for a first order fit of the three points below as $11.388612x - 301.878$.</p>
<pre><code> x, y
35, 0
430, 4861
656, 7000
</code></pre>
<p>It also shows a field labeled: "RMS: 329.499" </p>
<p>How is that RMS calculated? I tried RMSD as defined <a href="http:/... | g19504 | [
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<p>I built a fixed effects model using time series cross sectional data. The model was built using PROC MIXED in SAS. There are 2 effect coded attributes in the model and inteactions. One dummy variable has 12 levels ($MO$), the other has 16 levels ($MSA$). My question has to do with interpreting and graphing the int... | g62424 | [
0.005720007698982954,
-0.051135096698999405,
-0.006698633078485727,
-0.03785542771220207,
0.05154668167233467,
-0.00901864841580391,
0.04184160381555557,
0.002749080304056406,
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0.0033627122174948454,
-0.022698506712913513,
0.06146535649895668,
0.024510027840733528,
-0.... |
<p>I am going to teach undergraduate laboratory exercises for linear regression models in either Matlab or R.</p>
<p>Is there any book that is not emphasizing a lot in theory but focuses mostly in applications and in examples with any of the above languages?</p>
<p>I want to thank you all for your insights and for ti... | g19505 | [
0.0380825512111187,
-0.04716138169169426,
0.017354100942611694,
-0.012095272541046143,
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-0.004151879344135523,
0.0016154106706380844,
0.017918704077601433,
0.022433873265981674,
... |
<p>Suppose I have data that are generated like this:</p>
<ol>
<li>An argument $i$ comes to $c_i \in \mathbb{N}_0$ conclusions, where $i \in N,|N|=n$.</li>
<li>A respondent assigns $f_{ij} \in \mathbb{N}_0$ fallacies to conclusion $j$ of argument $i$.</li>
<li>I divide the total number of fallacies by the number of con... | g19506 | [
0.04858476296067238,
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0.020949598401784897,
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-0.010926197282969952,
-0... |
<p>The classical case for Multi-Level Models are data domains where each 'individual' belongs to some group, like pupils to school classes. In such a case, the individuals are distributed into disjoint buckets like this:</p>
<pre><code>---------------------------------------------
| Class1 | Class2 | Class3 | C... | g62425 | [
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... |
<p>Answers to a questionnaire - Frequency of activity X</p>
<ul>
<li>1 - 5</li>
<li>6 - 10 </li>
<li>10 - 20</li>
<li>20 or more</li>
</ul>
<p>I have two questions regarding these answers:</p>
<ul>
<li>Uneven bins, the answer 10 to 20 has twice the number of numerical answers, if you were to analyse this data after ... | g19508 | [
-0.028495704755187035,
0.03756483644247055,
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0.034144092351198196,
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0... |
<p>Say I have <strong>two different datasets</strong> with a few hundred cases and 100 predictors each. The dependent variable in both dataset is the class (nominal) to which a case belongs, but in the first dataset, there are 15 such classes, whereas the second dataset only has 10 different classes. In principle, howe... | g62426 | [
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0.012472766451537609,
0.06337710469961166,
-0.00416789622977376,
0.056939687579870224,
0... |
<p>I have this model: </p>
<p>$$4F + 4.8N = a + bM +cP + dH$$</p>
<p>where $F$, $N$, $M$, $P$, $H$ are variables measured on a 7-point Likert's type scale and $b, c, d$, are coefficients and $a$ is a constant. I am using SPSS.</p>
<p>My question: $F$ and $N$ are both measured with 5 items. What formula do I use to ... | g19511 | [
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-0.023942213505506516,
-0.015548636205494404,
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0.049707986414432526,
0.028063587844371796,
0.... |
<p>I'm having some troubles with the implementation in pyMC of my probabilistic model.</p>
<p><strong>Note: you can skip directly to the code section, if you're not interested on the use of the model.</strong></p>
<p>The model itself is going to be used to extrapolate information about different the style of a 3D mod... | g36455 | [
-0.015943560749292374,
-0.048048797994852066,
0.010867234319448471,
-0.04602228105068207,
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-0.05030272156000137,
0.048603374511003494,
-0.02579851821064949,
0.058131925761699677,
0... |
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