slepc-3.23.1 2025-05-01

STMatSetUp

Build the preconditioner matrix used in STMatSolve().

#include "slepcst.h" 
PetscErrorCode STMatSetUp(ST st,PetscScalar sigma,PetscScalar *coeffs)

Collective

	st	- the spectral transformation context
	sigma	- the shift
	coeffs	- the coefficients (may be NULL)

This function is not intended to be called by end users, but by SLEPc solvers that use ST. It builds matrix st->P as follows, then calls KSPSetUp().

    If (coeffs)  st->P = Sum_{i=0..nmat-1} coeffs[i]*sigma^i*A_i
    else         st->P = Sum_{i=0..nmat-1} sigma^i*A_i

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