# All Questions

51 views

### Differences in edition of advanced statistics books

In general I'm wondering if there's any danger in studying from older edition statistics books. The undergrad material seems to have remained unchanged throughout the last century, but I'm looking for ...
4 views

### How to train input feature weights for a path optimization problem?

I am working on a general path optimization problem. As many of you know, once the weights on all nodes are determined, one may solve this problem in many different means. Unfortunately, my raw input ...
9 views

### Motivation of Projection Pursuit

Given I understand why PCA aims to maximize variance, I wonder why finding non-gaussian projections is interesting for Projection Pursuit, i.e., what is the motivation of this reasoning?
12 views

### Filter algorithm for a system

I have a system with the following structure: $X_{t+1} = X_t + E_{t+1}$ $E_{t+1} \sim N(0, \Sigma)$ $Y_{t+1} = f(X_{t+1})$ $Y_{t+1} \sim {\rm Uniform}(a_{t+1}, b_{t+1})$ So $X$ is a vector of ...
18 views

### ROC curve and its function beginner

I have 3 features of a signal (example: amplitude, frequency, energy). I want to check which feature is the best to represent that particular signal. That signal is classified into two categories ...
18 views

### How to Obtain “Right” Parameters of Multinomial Logit Model (or Other Conditional Models) in R?

I started to use the function multinom of R package nnet in order to fit several conditional ...
22 views

### How would I find the P-Value of this data?

I have the following data (relating to consecutive months at current job): Mean: 45.4 Standard Deviation: 60.89 Sample Size: 48 I am asked to do a one-tailed test at a 1% significance level and ...
90 views

### Do Beta weights from regression have error terms?

I am looking at standardized regression weights (i.e., Beta weights). I was thinking of reporting the errors next to the weights in a figure, but upon some thought I was debating whether such errors ...
60 views

### How to compare whether the coefficients of two independent variables statistically different from each other?

If I have two independent variables and they are dummy variable along with other independent variables and I run a linear probability model, I want to compare whether the coefficients of two dummy ...
22 views

### Probability of Two Samples Containing Overlapping Data

Quick question about sampling a data population that contains non-overlapping data: if I take two samples of 50 from a population of 100,000 unique data points, how would I calculate the probability ...
81 views

### Why do I not get a p-value from this ANOVA in R?

Here's the data: ...
11 views

### Robust variance estimators

Given $N$ data points in $\mathbb{R}^p$ - some of which are outliers (drawn from a different distribution from the inliers) - what sorts of algorithms have been designed to estimate the robust ...
24 views

### Why is the anova p-value on these series of numbers not significant

I have three different samples (three replicates per sample) and lots of variables (1000+) This variable in particular had the largest VIP number from an Orthogonal signal correction PLS-DA of these ...
17 views

### Understanding biplot for compositional data

Say in the biplot of some compositional data, I discovered that the links $\vec{AB}$ and $\vec{CD}$ intersect at roughly 90 degrees. So I can say that $\log {A\over B}$ and $\log{C\over D}$ are ...
10 views

### Simulation from mixture of Weibull distributions

I would like to simulate a random sample from mixture of two Weibull distributions(or three Weibull components) which at the end have a bathtub-shaped hazard function ? I wrote the following code but ...
41 views

### Poisson distribution confidence interval

Edit : this is the data I used for the first part of the problem : \begin{matrix} Rocks & 0& 1& 2& 3& 4& 5& 6 & 7\\ samples & 12& 27& 28& 19& ...
6 views

### Stieltjes transformation for empirical distribution function

If the eigen-decomposition of sample covariance matrix is $S=PDP'$ where $D$ is a diagonal matrix with eigen value of $S$ and $P$ are eigenvectors. If we define the empirical distribution function of ...
4 views

### Combined hypergeometric distribution of exclusive sets

Given the following: a set of numbers, 1 to 20 four sets of five numbers from the set above (each number used once) a draw of five different numbers from the first set How would I determine the ...
24 views

### Plotting fitted values for an nlme model

I just got the output of my lme (nlme) model called shalit5 with syntax: ...
17 views

### Robust standard errors for cross-sectional data: what is a “large” sample size?

I know that others have asked about robust standard errors (Robust standard errors in econometrics and Always Report Robust (White) Standard Errors?). An answer to the latter question made this ...
15 views

### probit two stage least squares

I was told that it's possible to run a 2 stage iv regression where the first stage is a probit and the second stage is an OLS. Is it possible use 2sls if the first stage is a probit but th second ...
10 views

### Construct matrix of stacked variables in VAR regression

I am trying to NOT use packages for the estimation of models in order to have a deeper understanding of how things work. Currently, I am trying to estimate a VAR(1) (vector autoregression of first ...