# Questions tagged [matrix]

Questions on the manipulation of matrices in Mathematica.

2,379 questions
Filter by
Sorted by
Tagged with
177 views

### How can I get all 4x4 submatrices of an nxn matrix?

I have a square matrix, I need to extract all possible combinations of 4x4 submatrices, where n>4. For example in the case of a 6x6 matrix, there are 15 4x4 submatrices. I need the list of all 4x4 ...
321 views

### How to reduce the λ-matrix to Smith Standard Form

A = {{1 - λ, 2 λ - 1, λ}, {λ, λ^2, -λ}, {1 + λ^2, λ^3 + λ - 1, -λ^2}} How to reduce the above λ-matrix to the following Smith standard form: ...
44 views

### Find vectors describing two interconnected pyramids in Euclidean space

I need the help of competent linear algebra specialists in Mathematica. In the Euclidean space, two tetrahedrons are turned at different angles. Their vertices coincide with the beginning of the base ...
30 views

### Exporting column vector as matrix in latex via “Copy as” doesn't always work. Example with vector

I want the simplest way of exporting matrices, and vector from mathematica to Latex. Usually, I display my matrices in MatrixForm and copy as Latex to paste in my latex document. However it seems it ...
120 views

### Cell-adjacency Graph of a Square Mesh

Consider the list of points pts = {{1, 1}, {1, 2}, {2, 1}, {2, 2}} I want to use them to define a 2x2 square mesh using ...
58 views

### Keep important eigenvectors according to the important eigenvalues except one unimportant eigenvalue

I have an iteration whose steps extract a matrix with any possible dimension for example 3*3, 6*6, ...
228 views

### Adjacency Matrix of Sierprinski matrix

how can i make adjacency matrix of sierprinski graphs?
64 views

### Nested For Do Table cycle problems

I got England and German soccer data with the following: ...
43 views

72 views

### Proving the positive semidefiniteness of a 6X6 symbolic matrix

Specifically, I want to check the positive semidefiniteness of the following 6X6 symbolic matrix ...
17 views

### Symbolically invert block matrix [duplicate]

In Mathematica, if I write something like: Inverse[{{a, b}, {c, d}}] I get the inverse: ...
73 views

### Crisis in vector notation [closed]

How to write a vector in Mathematica so that one can perform the common operations such as Transpose and Normalize. For example, {1, 1} can be normalized but not ...
51 views

### How do i transform a Matrix into a List? [duplicate]

Like the title says i want to transform a Matrix into a list so i can use LinearSolve what's the way to do it? ...
115 views

### Create a Vandermonde matrix

I want to create a $n \times n$ Vandermonde matrix. How could I set up a matrix, vMatrix so I can just use ...
121 views

### Minimizing expression over symmetric matrices

I'm trying to solve the following maximization problem over space of symmetric matrices A and positive definite H $$R=\max_{A\in S(R^d)}\frac{\text{tr}(HA)^2+2\text{tr}(HAHA)}{\text{tr}(AHA)}$$ So ...
78 views

### Verifying: How to express a given matrix as the outer product of two vectors? [closed]

The question posed here and here is: Is it possible to decompose a matrix $M_{m\times n}$ as the product of two vectors, i.e. $$M_{m\times n} = \vec{y}_{m\times 1}\times\vec{x}_{1\times n}+const.$$ ...
112 views

### Gaussian elimination for a Hilbert matrix

I have been asked to write the Mathematica code to solve a 25x25 Hilbert matrix. The built-in function LinearSolve would not work. I started my solution by coding ...
54 views

### Error when trying to solve elastic PDEs using FEM: “Compile::argcompten: The comparison, LessEqual, is invalid for tensor arguments.”

I'm trying to solve the following linear elastic problem: The pairs of numbers beside each node is the coordinates in meters. The loads are in Newtons. The part of codes that probably have no ...
I want to create a matrix of the form: $X_\alpha = 1\otimes 1\otimes 1 ...\otimes X \otimes ... \otimes 1$ where $X$ is the Pauli $x$ matrix and is the $\alpha$th factor, and $1$ is the $2\times 2$ ...