xref: /petsc/src/mat/tutorials/ex6f.F90 (revision a336c15037c72f93cd561f5a5e11e93175f2efd9) 
1!
2!     Demonstrates use of MatShellSetContext() and MatShellGetContext()
3!
4!     Contributed by:  Samuel Lanthaler
5!
6#include "petsc/finclude/petscmat.h"
7module solver_context_ex6f
8  use petscsys
9  implicit none
10  type :: MatCtx
11    PetscReal :: lambda, kappa
12    PetscReal :: h
13  end type MatCtx
14end module solver_context_ex6f
15
16! ----------------------------------------------------
17!                    main program
18! ----------------------------------------------------
19program main
20  use petscmat
21  use solver_context_ex6f
22  implicit none
23
24  Mat :: F
25  type(MatCtx) :: ctxF
26  type(MatCtx), pointer :: ctxF_pt
27  PetscErrorCode :: ierr
28  PetscInt :: n = 128
29
30  PetscCallA(PetscInitialize(ierr))
31  ctxF%lambda = 3.14d0
32  PetscCallA(MatCreateShell(PETSC_COMM_WORLD, n, n, n, n, ctxF, F, ierr))
33  PetscCallA(MatShellSetContext(F, ctxF, ierr))
34  print *, 'ctxF%lambda = ', ctxF%lambda
35
36  PetscCallA(MatShellGetContext(F, ctxF_pt, ierr))
37  print *, 'ctxF_pt%lambda = ', ctxF_pt%lambda
38
39  PetscCallA(MatDestroy(F, ierr))
40  PetscCallA(PetscFinalize(ierr))
41end program main
42
43!/*TEST
44!
45!     build:
46!       requires: double
47!
48!     test:
49!
50!TEST*/
51