# Tag Info

### Nonnegative Least Squares Algorithm (NNLS)

We can compare 6 algorithms based on FindMinimum,NMinimize, ConvexOptimization, ...

### Is it possible to use the DGEEV and DSYEV LAPACK subroutines in Mathematica?

You can use LibraryLink to call LAPACK directly. It involves however quite a lot of boilerplate code. Here is an example: ...
Accepted

### How to obtain independent variables from a set of linear constraints

First one can set up and solve the system. ...

### How to get a rational solution of the linear system efficiently?

Get the same result about four times faster with NMinimize and rationalization. (Using the format for variables, @BobHanlon proposed.) ...

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### How can I generate a tridiagonal block matrix?

It must be many ways to do this,here we provide one way. ...

### How to find the index of a square matrix in Mathematica quickly?

In version 13.0.1, there is a undocumentation function LinearAlgebra`MatrixIndex. But I'm not sure when this is introduced ...

### Solution to a linear equation with minimum rank

Your transposed equation looks like Transpose[M].Transpose[X]==Transpose[A] LeastSquares finds the minimal solution ...

### Solution to a linear equation with minimum rank

We can use Nonnegative Least Squares Algorithm (NNLS) discussed here to solve matrix equation X.M=A with constraints ...