[petsc-users] Creating random matrices and doing Least squares in PETSc

[Gaurish Telang]

Hi, this might be a vague question but is it possible to create a
random rectangular matrix in PETSc of arbitrary specified dimension? More
specifically,  I would like the rectangular matrix to be sparse and have
1.14% non-zeros in the matrix.

If there is no such direct way,  is there a way for MATLAB to do this and
then possibly output it to a text file so that it could be fed to PETSc?

The thing is I want to know how fast PETSc does least squares problems
|Ax-b| for matrices A of dimensions like 2683x1274 where A is sparse with
about 1.14% non-zeros.

If you have any kind of timing studies / weblinks describing how fast PETSc
does least square problems that would be really helpful.

Sincere thanks,

Gaurish.
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