On Jan 16, 2011, at 6:23 PM, Gaurish Telang wrote: > 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?
use $PETSC_DIR/bin/matlab/PetscBinaryWrite.m to save the matrix to a fast binary format then use MatLoad() to load it into PETSc Barry > > 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.
