# Tagged Questions

A matrix (plural matrices) is a rectangular array of numbers, symbols, or expressions arranged in rows and columns. The individual items in a matrix are called its elements or entries.

29 views

### How to get non-negative solutions to matrix in R?

I am trying to solve the equation AX = B in R. I have two matrices, A and B: ...
10 views

### Scaling Variance-Covariance Matrix of daily returns to quarterly

I am trying to convert my variance-covariance computation, which is based on daily returns of 700 points of data, into a different scale/time period. I am trying to basically have the computed result ...
17 views

### Matrix Calculations and Multivariate Bayesian Methods

Suppose I have the matrix given by: $$X = \begin{bmatrix}1 & 0 & 0\\ 1 & 1 & 0 \\ 1 & 1 & 1 \end{bmatrix}$$ This matrix actually represents whether a user interacted with a ...
51 views

### Latent Semantic Analysis- Theme extraction [closed]

I have a large collection of text documents I am trying to group using Singular Value Decomposition for dimension reduction(popularly known as LSA) followed by k-means clustering. To be able to ...
21 views

### Summation constraint matrix

I'm trying to create an assignment script using the R package Rsymphony, but I can't seem to figure out how to convert the summations into an actual constraint matrix. I tried to figure it out based ...
59 views

### Calculate matrix exponential without dedicated software package [closed]

Is it possible to determine the exponential of a square (non-diagonalizable) matrix without a dedicated package: for example, through a series of equations within a spreadsheet?
43 views

### Help understanding p-vector language

Help interpreting this excerpt (annotations (numbers in parentheses) and bullets added) from The Elements of Statistical Learning Matrices are represented by bold uppercase letters; for example, a ...
34 views

### computation of square root of matrix

I am studying the Canonical correlation analysis(CCA) the formula https://en.wikipedia.org/wiki/Canonical_correlation is involving the -1/2 degree of a matrix. My question is: how can i do the ...
33 views

### Asymmetric matrix in Mantel test?

Does anyone know how to set up an asymmetric matrix to do a Mantel test? The reading I've done says the Mantel stat can be calculated from these matrices, but all packages/programs that I use to run ...
41 views

### Doing a “linear regression” with 2d points under a linear transformation

Let's say I have a list of 2D points $\vec v_i = (x_i,y_i)$ and the list of points after some linear transformation $\vec v_i'= A\vec v + b + \epsilon_i$ where $\epsilon_i$ is some deviation assumed ...
114 views

41 views

### Covariance matrix through bootstrapping - close to zero determinant

I have a set of 260 sets of measurements (for each set of measurements there is an amplitude measured as a function of 8 radii). Since I do not get measurement errors and I am interested in the ...
49 views

### Sort Table Rows/Columns to Minimize Distance

I am working on a project where I am given a large table of numbers, in which we are hoping to see certain patterns. For example (using R): ...
36 views

### Chi-square and R: Calculate matrix of statistical significances between results

First of all, I would like to apologize if this is an duplicate of an earlier question. I find it hard to believe that I am the first person to ever have this sort of problem, but I am so far out of ...
27 views

### Interpreting the Structure matrix in Discriminant Analysis

I was trying to do a discriminant analysis in SPSS and I have to interpret the output. But when I come to the table of Structure Matrix, I find difficulty in defining the variables I should use in ...
19 views

### SVD - collaborative based filtering - Prediction matrix

On the movielens dataset, I used SVD to find U, s, and V matrices. Then performed the dimensional reduction by elimination of everything corresponding to lower valued eigen values( upto a threshhold). ...