# All Questions

2 views

### How to get the Eigenvalues from Multidimensional Scaling?

I am interested in taking a look at the Eigenvalues after performing Multidimensional scaling. What function can do that ? I looked at the documentation, but it does not mention Eigenvalues at all. ...
3 views

### Can anyone suggest some real applications of Induced order statistics

I am working in the field of Order statistics and I need some help in using the concept of induced order statistics in real application. I will be very grateful if anyone can suggest some real life ...
4 views

### regarding the convolutional structure of FCNN

The paper of Fully Convolutional Networks for Semantic Segmentation , gives the following image, . What do those numbers represent, 96, 256, 384, etc? Are them ...
10 views

### How to select the best number of clusters in cluster analysis in SPSS?

When I used SAS for cluster analysis, I used to use some plots of CCC, pseudo F and pseudo T^2 indices to help determine best the number of clusters. Not sure about this in SPSS, not familiar with ...
9 views

### How to change the y axis on MGCV GAM factor plots?

I'd like to adjust the y limits on plots of GAM smoothing functions and factors to more easily compare the effects of two different GAM models for different seasons. When using the ...
13 views

### Can I perform a signed-rank test on a weighted sample in R?

I would like to perform a signed-rank test on two paired, ordinal variables in R. Such a non-parametric test is required, as neither of the variables follow normal distribution. Both variables ...
6 views

### Replying the canonical discriminant analysis on the test set

I run a canonical discriminant analysis following those 2 video lessons on Coursera. Now, I would like to test the accuracy of the clustering methodology on a test set by replicating the canonical ...
7 views

### Bayesian estimation of Dynamic Linear Models with RStan

I'm reading the Dynamic Linear Models with R book, where most of chapter 4 is devoted to bayesian estimation of parameters. They code most of it manually though, and it seems it can get quite tricky ...
14 views

### Variance/distribution of categorical data

I am currently analyzing large data sets with various characteristics (such as city). I wanted to find a measure which would essentially say how much or how little of a variance there was across the ...
12 views

### What is an acceptable R squared range for cross sectional data linear regressions?

May I know an acceptable R squared range for a cross sectional data analysis using linear regression? I think the requirement for this is lower than time series or panel data but would like to know ...
6 views

### factor analysis using Maximum likelihood or Principle axis factor to extract factors for 6 point likert type questions?

We have a questionnaire, which have many questions on 6-point likert scale. So these variables are ordinal, not normally distributed. In performing factor analysis, there are two major methods in ...
6 views

### multiple imputation and propensity scores

I have a dataset with 1300 observations and 30 variables. One of the variables has 10% missing data, another has 5% and a third has 3%. Seeing Propensity score matching after multiple imputation I ...
15 views

### Derive z- or t-statistic from p-values of regression coefficients from a probit/logit model

I have the results from an empirical study reporting the results for a probit and logit model. They just report the p-values of the regression coefficients. I want to derive the corresponding $t$-/$z$-...
10 views

### Elements-wise matrix algebra in R arrays [migrated]

I have two arrays with dimensions: arry1[2,2,n] and array2[2,2,n]. That is, n two by two matrices. I want to produce a third array which is the n-element-wise matrix multiplication (i.e., %*%) of ...
12 views

### drawbacks of woe (weight-of-evidence) transformation

I have read a few posts about woe transformation. It seems that most are about the pros. That makes me think: if woe is that effective in logistic regression, then there is no reason for not doing it. ...
18 views

### The proof of lasso regression solution? In which it shrinks some of coefficents to zero? [duplicate]

I would like to know how the lasso method shrinks some of coefficients exactly to zero, "for example could show me how that works mathematically if there are two parameter". For example, with ridge ...
11 views

### Freeman & Tukey interval

If $Y$ is $\text{Poisson}(λ)$ distributed, how do we obtain this confidence interval for $λ$: $\:l=\frac14 [(\sqrt{Y}+\sqrt{Y+1}-z_{α/2} )^2-1]$ $u=\frac14 [(\sqrt{Y}+\sqrt{Y+1}+z_{α/2} )^2-1]$
15 views

### Observation dependency in logistic regression to learn relevance of search results

I want to predict the most relevant item from a set of search results resulting from a query. Moreover, these items are places; the query is at a lat/long and time; and the search results are ...
10 views

### How to identify parameters of distributions of a mixture when many samples are sum of the samples?

I have a list of values which are samples from 4 different normal distributions. The list also contains sum of two or three sample values. I would like to identify parameters of the distributions. An ...
4 views

### How does the Identity connection in ResNets work

I am currently going through the Research paper "Deep Learning for Image recognition" by Kaiming He. I don't quite understand the concept of shortcut connections. Suppose the input to the residual ...
7 views

### Self Study[HMM for time series, Zucchini, MacDonald]: Compute ordinary pseudo-residual of discrete r.v

I am reading chapter 6 of the book 'Hidden Markov Models for Time Series An Introduction Using R' and I am trying understand how to compute ordinary pseudo-residuals when the distribution is discrete [...
12 views

### How many « degrees of freedom » should a Wilcoxon rank-sum test have?

I would like to perform a Mann-Whitney U Test (also called Wilcoxon rank-sum test) on a weighted sample in R. Such a non-parametric test is required, as neither of the two variables used follow normal ...
6 views

### What are the margin guarantees for decision tree based classifiers? [on hold]

Could someone explain what the margin guarantees are for decision trees? Please share relevant publications. Thanks.
10 views

### What kinds of objective functions can be expressed as frequentist risk functions?

Suppose that the best estimate for some application is the one that minimizes squared bias: $$(\mathbb{E}[\hat\theta(U)]-\theta)^2.$$ It doesn't seem like this objective can be expressed as a (...
27 views

### Distribution of the sum of the two dependent bivariate gaussian distributions and related questions

This is something I was thinking about and I decided to modify a question from a mid-term to ask this. Suppose $X_{1}$ and $X_{2}$ are two bivariate gaussian variables, decribed as  X_{i}=\begin{...
31 views

### Sugest Vaible Research Area in Optimum Block Lenght for Block Time Series Bootstrap [on hold]

I am having something in mind concerning a thesis in Statistics; it is the "optimal block length for block bootstrap". the issue is that much work is also done on it already. Can anyone please guide ...
29 views

### Is there a database for non time series data sets? [duplicate]

I am searching for some data sets that would be suitable for regression analysis that my teacher wants for Statistical Learning lesson's homework. But as I search I only encounter with time series ...
6 views

### for a survey conducted in 3 countries, how to examine the equivalence of factor structure by country?

We conducted a survey in 3 countries, and we want to run factor analysis (EFA) to identify latent factors. With the combined data sets, we can run EFA to develop factors. But to examine the ...
7 views

### Hawthorne effect in clinical research, definition and advice for non-parallel designs

Hawthorne effect is simply described as a bias in performance as a consequence of being under observation. The first study in which it was observed and it's namesake was a study of workers, and they ...
28 views

### How to deal with categorical variables in regression [on hold]

I have 3 levels of categorical variables for different programs. I have run a regression model on them in R with the following modifications: ...
34 views

### how to check missing data is missing at random or not?

I have a survey data, in which there are some missing data (not answered questions). I threw away those where the whole page(s) questions were missed, but there are still some with unanswered ...
21 views

### One question about Owen's book “Empirical Likelihood” [on hold]

I am doing a dissertation which talks about the application of empirical likelihood. In Owen's book, page 39, it talks about how to figure out the confidence intervals for the volatility of the S&...
7 views

### regarding computing output size for convolutional layer

I am following up the lecture notes posted on http://cs231n.github.io/convolutional-networks/ I am sort of confusing about one example given in the notes. It says ...
9 views

### How to plot mean by classes in R? [on hold]

I want a data file as follows: ...
12 views

### Simple syntax spss question [on hold]

I am new to SPSS and I probably have a basic question. I have a syntax on a different file which has the file name .sps and a register with the file name .sav. The syntax should be a variable in my ...
9 views

### Using randomisation of fixed effects for a psuedo-p in mcmc glmm

I'm running generalized linear mixed models in R using the function MCMCglmm(), and with summary this generates p (pMCMC) values. However, pMCMC is, by the authors own admission, not perfect: "...
12 views

### How do I know if a model with a subset of the features of another model has lowest training/test error?

I'm doing the Machine Learning specialization from the University of Washington on Coursera, and I have to answer some questions in a quiz from the Regression course. They ask which model would have ...
7 views

### important service feature types: KDD dataset

I am working with the KDD dataset with too many features for my evaluation. I have a problem in understanding of what some of the attributes of the service features are. I can't find any documentation ...
25 views

### Advantages and disadvantages of EM algorithm vs trust region methods for nonlinear optimization

I have a set of observations X that I believe were generated by a mixture of several probability distributions (specifically, two von mises and one uniform). I'd like to find the maximum likelihood ...
16 views

### Effect of an auditor's experience on client size and client complexity

I am working on a dataset containing a list of auditors, collected in four different years: 2008: 650 auditors 2009: 646 auditors 2010: 635 auditors 2011: 620 auditors (A possibly large number of ...
11 views

### how the interaction between one binary variable with several binary variables modeled in logistic?

I want to assess the interaction among genotype (coded as 0 and 1) and dietary intake {(fat intake ‎‎(coded as 0 and 1), carbohydrate intake (coded as 0 and 1 and also energy intake (coded as 0 and 1)}...
13 views

### Restaurant Transaction Predictions

I'm new with R and have an intermediate background in stats. I'm developing a model that predicts the hourly transactions that a restaurant has. I work for a fast food chain in Latin America (we have ...
28 views

### Understanding the meaning of $n = 1$ in the Bernoulli distribution

I am not very familiar with the Bernoulli distribution and am seeking to understand when to use it rather than other, more common binomial distributions in machine learning models. I began by reading ...
5 views

### PSM with exact matching

I am evaluating and educational program with a PSM in STATA. Suppose that T= variable of treatment X= cofounders Z= variable with exact matching Y = output ...
16 views

### Diff-in-Diff with a small N (N=20) and a small number of treated units (2 or 1), but with large T (T=80). What are the main problems?

What are the main problems one may have when estimating a diff-in-diff model with small N (N=20), small number of treated units (2 units) and a large T (T=80)?
10 views

### How to compare means of 3+ variable within a sample group

Grip strength for 128 athletes was measured at 3 various elbow angle (90, 180, 45) with varying position and arm posture. Now I want to compare means of dependent variables within each elbow ...