KSPSetResidualHistory

Sets the array used to hold the residual history. If set, this array will contain the residual norms computed at each iteration of the solver.

#include "petscksp.h" 
PetscErrorCode PETSCKSP_DLLEXPORT KSPSetResidualHistory(KSP ksp,PetscReal a[],PetscInt na,PetscTruth reset)

Not Collective

	ksp	- iterative context obtained from KSPCreate()
	a	- array to hold history
	na	- size of a
	reset	- PETSC_TRUE indicates the history counter is reset to zero for each new linear solve

Notes: The array is NOT freed by PETSc so the user needs to keep track of it and destroy once the KSP object is destroyed.

If 'na' is PETSC_DECIDE or 'a' is PETSC_NULL, then a default array of length 1000 is allocated.

KSP, set, residual, history, norm