slepc-main 2024-11-09
BVSetRandomSign
Set the entries of a BV to values 1 or -1 with equal probability.
Synopsis
#include "slepcbv.h"
PetscErrorCode BVSetRandomSign(BV bv)
Logically Collective
Input Parameter
Notes
All active columns (except the leading ones) are modified.
This function is used, e.g., in contour integral methods when estimating
the number of eigenvalues enclosed by the contour via an unbiased
estimator of tr(f(A)) [Bai et al., JCAM 1996].
Developer Notes
The current implementation obtains random numbers and then replaces them
with -1 or 1 depending on the value being less than 0.5 or not.
See Also
BVSetRandomContext(), BVSetRandom(), BVSetRandomColumn(), BVSetActiveColumns()
Level
advanced
Location
src/sys/classes/bv/interface/bvops.c
Index of all BV routines
Table of Contents for all manual pages
Index of all manual pages