#include "petscsnes.h" PetscErrorCode SNESComputeJacobianDefault(SNES snes,Vec x1,Mat J,Mat B,void *ctx)Collective on SNES
snes | - the SNES context | |
x1 | - compute Jacobian at this point | |
ctx | - application's function context, as set with SNESSetFunction() |
J | - Jacobian matrix (not altered in this routine) | |
B | - newly computed Jacobian matrix to use with preconditioner (generally the same as J) |
-snes_fd | - Activates SNESComputeJacobianDefault() | |
-snes_test_err | - Square root of function error tolerance, default square root of machine epsilon (1.e-8 in double, 3.e-4 in single) | |
-mat_fd_type | - Either wp or ds (see MATMFFD_WP or MATMFFD_DS) |
An alternative routine that uses coloring to exploit matrix sparsity is SNESComputeJacobianDefaultColor().
This routine ignores the maximum number of function evaluations set with SNESSetTolerances() and the function evaluations it performs are not counted in what is returned by of SNESGetNumberFunctionEvals().