PCApplyBAorABTranspose#

Applies the transpose of the preconditioner and operator to a vector. That is, applies \(B^T * A^T\) with left preconditioning, NOT \((B*A)^T = A^T*B^T\).

Synopsis#

#include "petscksp.h" 
PetscErrorCode PCApplyBAorABTranspose(PC pc, PCSide side, Vec x, Vec y, Vec work)

Collective

Input Parameters#

  • pc - the preconditioner context

  • side - indicates the preconditioner side, one of PC_LEFT, PC_RIGHT, or PC_SYMMETRIC

  • x - input vector

  • work - work vector

Output Parameter#

  • y - output vector

Note#

This routine is used internally so that the same Krylov code can be used to solve \(A x = b\) and \(A^T x = b\), with a preconditioner defined by \(B^T\). This is why this has the funny form that it computes \(B^T * A^T\)

See Also#

KSP: Linear System Solvers, PC, PCApply(), PCApplyTranspose(), PCApplyBAorAB()

Level#

developer

Location#

src/ksp/pc/interface/precon.c

Index of all PC routines
Table of Contents for all manual pages
Index of all manual pages