# All Questions

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### multiple local optimum solutions when we solve a linear regression?

I read this statement on one old exam that be (True / False). We can get multiple local optimum solutions if we solve a linear regression problem by minimizing the sum of squared errors using ...
25 views

### Replicating SPSS factor analysis/PCA in R [on hold]

I am trying to replicate SPSS factor analysis/principal component analysis results in r using two previously suggested methods, but neither has succeeded. (What are the differences between Factor ...
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### Specifying interaction term within nested factors in lmer [on hold]

I'm trying to understand how to include a nested term within an interaction effect in a mixed model ANOVA. Data: Factor A (Fixed) Factor B (Random) Factor C (Random) Factor D (Random) Model: ...
32 views

### Variance of slope

I have a bunch of data that I fit a linear regression to, and now I need to find the variance of my slope. Is there an analytical way to get this? If an example is necessary, consider this my data in ...
9 views

### Http Server Using Torch7 [on hold]

I'm starting to learn Torch7 to get into the machine learning/ deep learning field and I'm finding it fascinating (and very complicated haha). My main concern, however, is if I can turn this learning ...
7 views

### degrees of freedom for chi squared problem [on hold]

For an equiprobable chi-squared goodness of fit test with an HO of uniformly distributed with the same parameters as the sample for 24 obs., you would have how many degrees of freedom. the answer ...
42 views

### Simple Question about ROC Curve

Motivated by this reference, it states under ROC Space When evaluating a binary classifier, we often use a Confusion Matrix...however here we need only TPR and FPR I'd feel more comfortable if ...
27 views

### Cluster the repeated measure data [on hold]

So I have the data that looks something like this ...
24 views

### ols and multiple regression model wth two variables

My model is as follows: $y=b_1*X+b_2*\max(X,0)+u$ Will I have any problems with the variables $X$ and $\max(X,0)$, concerning any correlation issues? Can I just apply the classic OLS methodology?
18 views

### Jackknife vs. LOOCV

Is there really any difference between the jackknife and leave one out cross validation? The procedure seems identical am I missing something?
20 views

### How to do a stepwise regression in R using Mallows' criterion Cp? [on hold]

I have about 20 variables (interactions included) in my multiple regression analysis. I would like to do a stepwise regression(backward, forward, stepwise) in R using the Mallows criterion. I struggle ...
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### On forecasting, the mean squared error and realized volatity

Say one has finished estimating a correctly specified GARCH(1,1) on a daily time series and now wants to evaluate the accuracy of the one step ahead forecasts what steps or tests could one do? I ...
33 views

### Getting an Excel file with many sheets into R [on hold]

I am importing data from an Excel file that contains 15 sheets. Each sheets represent a year in which there are observations on the same variables. Here is what I would like to do (elgantly) from R: ...
18 views

### Normalized data and regression

Suppose I have eight subjects and measured performance in a time series (outcome measure is a distance measure). I assess learning effects across these time points by expressing the increase in ...