slepc-3.21.0 2024-03-30
MatNormEstimate
Estimate the 2-norm of a matrix.
Synopsis
#include "slepcsys.h"
PetscErrorCode MatNormEstimate(Mat A,Vec vrn,Vec w,PetscReal *nrm)
Collective
Input Parameters
| A | - the matrix
|
| vrn | - random vector with normally distributed entries (can be NULL)
|
| w | - workspace vector (can be NULL)
|
Output Parameter
Notes
Does not need access to the matrix entries, just performs a matrix-vector product.
Based on work by I. Ipsen and coworkers https://ipsen.math.ncsu.edu/ps/slides_ima.pdf
The input vector vrn must have unit 2-norm.
If vrn is NULL, then it is created internally and filled with VecSetRandomNormal().
See Also
VecSetRandomNormal()
Level
developer
Location
src/sys/mat/matutil.c
Index of all sys routines
Table of Contents for all manual pages
Index of all manual pages