# All Questions

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### Confusion about nonlinear transformation of gamma and inverse-gamma distributions

I have a question about the variance of a transformed random variable, illustrated by a particular example. Let $X_1, ..., X_n$ and $Y_1, ..., Y_n$ be independent random variables drawn from an ...
10 views

### How to fit raw signal

I think this is simple, but somehow it's not working. I'm trying to fit my raw data so that basically I end up with beautiful 1 peak. I tried butterworth filtering, Gaussian fitting, a combination of ...
32 views

### Can I use bootstrapping in this situation?

I'm faced with a situation where there are few observations of a life insurance product in some cells, where the observations are deaths. The problem is that I need to calculate standard deviations ...
13 views

### Benchmarking Software Exercises

I am building a website for practicing programming in various languages. The content is user driven; some users write exercises with test frameworks for validating solutions, and other users write ...
10 views

### Using all the data for a decision tree prediction

When doing regression analysis with training and test sets, I would fit the model to the training data. When happy with the model fit I'd then run it against the test/holdout set to get a true ...
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### Factor analysis: what are the total possible scores for calculated factors based on Likert scale responses?

I have two factors, Peer Social Interaction (PSI) and Sense of Belonging (SB). Four Likert scale questions correspond to each factor. I used the factor loadings for each question to create a ...
13 views

### Discrete optimization with a very large solution neighborhood to explore

I have a problem whose feasible (discrete) solutions can measured by a cost function. I am thinking of using some optimization technique to get better solutions from a rough initial approximation. I ...
35 views

### R- Improving linear regression fit

I am trying to construct a predictive model in R. I am using the glm() in R to fit the model. I am getting a very high residual error after fitting the model. My target values are in the range of ...
14 views

### Category prediction in ordinal regression

This could be a naive question. I have three slabs for my dependent variable and when I run the ordinal regression the predicted responses are in first and third slab but no observation is predicted ...
46 views

### Confidence interval for $\eta^{2}$ for MANOVA in R

I have to report the Confidence Intervals for the $\eta^{2}$ obtained in a MANOVA in R. I use the function etasq of the package heplots to obtain the $\eta^{2}$. ...
21 views

### Best size for control in Control/A/B/C/D split test

I'm doing some split testing on a website, and have multiple tests running along with a control. Say we have control/A/B/C/D. If we only had control/A, then I know I should make them both the same ...
32 views

### Determine if regression results are significantly better with method A or method B

I'm working on a regression case and I am using two methods, lets say method A and B. Due to the randomness in the optimisation techniques of these methods the output will always differ slightly. ...
20 views

### Inverse-variance weighting

I'm writing a Bachelor Thesis in engineering an a small part of it has two deal with assigning weights to independent measurements. This is from the thesis: I am pretty sure that what equations ...
56 views

### Statistical publishing - english majors? [on hold]

This is a statistics question. Really. I have several topics that I would like to publish. While I can get a paper, in technical terms, 100% of the way done I am not an English major. I don't do ...
18 views

### Calculate statistical power on groups with different size

Is it technically possible to calculate the statistical power for a test where the two groups don't have by design the same size. I'm thinking to a 90%-10% split of the population. Namely, is there a ...
24 views

### How to compute RMSE for TBATS

Some forecasting models in R give error terms as their output. But for TBATS, I couldnt find out that how I can see what the RMSE for my data set is. Is there any specific command that I have to use ...
26 views

### Statistical Commute Analysis in Java

I have a rather large commute every day - it ranges between about an hour and about an hour and half of driving. I have been tracking my driving times, and want to continue to do so. I am capturing ...
20 views

### Data with weekly and annually seasonality but the first day in time series is not the begining of a week

I know it might look naive but I have a very basic question. I have a three years of historic data which has weekly and annual seasonality. January first as my first data is on Wednesday so my time ...
30 views

### Is there any difference between consistent statistic (outcome) and consistent estimator? [on hold]

Wikipedia and SE questions talk about consistent estimator. Interestingly, consistent estimator has been preconditioned as sample-size increases. We should talk about consistent estimate (statistic) I ...
30 views

### ROC (Epi library) how to calculate TP, FN,TN, FP

I'm trying to find how to compute the true negative (TN), false negative (FN), true positive (TP), and false positive (FP) if I have a cutpoint like in the following picture: ...
88 views

### What probability distribution best describes my data?

I have a variable whose values are summated scale scores with values ranging from 3 to 21. I considered this variable as a scale variable (though with restricted range). In order to model the relation ...
6 views

### regression test or two bloc PLS model to prove a gene expression matrix relationship

I have two gene expression matrices, matrix A coming from a set of two hypothetically different cells while matrix B is coming (for certain) from only one of them. The structure of a gene expression ...
11 views

### Odds Ratio in 2*3 Table

How can calculate Odds Ratio in 2*3 Table ( Participante [case -control] and marker [genotype])?
25 views

### Distribution of sum of two shifted Poisson

Suppose Y is shifted Poisson at "a", say Y -a ~Poisson (t) and X-b ~ Poisson (r), again a shifted Poisson at "b." Now what is the distribution of Z= X+ Y? Any idea? How to prove it?
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### Selecting variables in an SPSS-file (*.sav) using R [on hold]

I'd like to use a SPSS file (European Values Survey, to be more precise) in R. Specifically, I want to select certain variables (a country, a certain question [trust in armed forces] and the ...
37 views

### Simulate data for 2 x 2 ANOVA with interaction

What is the best way to simulate ANOVA data for a 2 x 2 design with interaction using a regression approach? I want to generate the data so that I know the true regression coefficients of the model ...