MatLMVMSymBadBroydenGetPsi#
Get the psi parameter for a Broyden class quasi-Newton update matrix
Synopsis#
#include "petscksp.h"
PetscErrorCode MatLMVMSymBadBroydenGetPsi(Mat B, PetscReal *psi)
Input Parameter#
B - The matrix
Output Parameter#
psi - a number defining an update that is an affine combination of the BFGS update (psi = 1) and DFP update (psi = 0)
Note#
If B does not have a constant value of psi for all iterations this will
return psi = PETSC_DETERMINE = -1, a negative value that psi cannot
attain for a valid general Broyden update.
This is the case if B is a MATLMVMSYMBROYDEN, where psi’s dual value
phi is constant and psi changes from iteration to iteration.
See Also#
KSP: Linear System Solvers,
MATLMVMSYMBROYDEN, MATLMVMSYMBADBROYDEN,
MATLMVMDFP, MATLMVMBFGS,
MatLMVMSymBadBroydenSetPsi(),
MatLMVMSymBroydenGetPhi(), MatLMVMSymBroydenSetPhi()
Level#
advanced
Location#
src/ksp/ksp/utils/lmvm/symbrdn/symbrdn.c
Index of all KSP routines
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Index of all manual pages