petsc-3.7.1 2016-05-15
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SNESComputeJacobian

Computes the Jacobian matrix that has been set with SNESSetJacobian().

Synopsis

#include "petscsnes.h"  
PetscErrorCode  SNESComputeJacobian(SNES snes,Vec X,Mat A,Mat B)
Collective on SNES and Mat Many br

Input Parameters

snes - the SNES context Many br
x - input vector Many br

Output Parameters

A - Jacobian matrix Many br
B - optional preconditioning matrix Many br

Options Database Keys

-snes_lag_preconditioner <lag>- . -snes_lag_jacobian <lag> Many br
-snes_compare_explicit - Compare the computed Jacobian to the finite difference Jacobian and output the differences Many br
-snes_compare_explicit_draw - Compare the computed Jacobian to the finite difference Jacobian and draw the result Many br
-snes_compare_explicit_contour - Compare the computed Jacobian to the finite difference Jacobian and draw a contour plot with the result Many br
-snes_compare_operator - Make the comparison options above use the operator instead of the preconditioning matrix Many br
-snes_compare_coloring - Compute the finite difference Jacobian using coloring and display norms of difference Many br
-snes_compare_coloring_display - Compute the finite differece Jacobian using coloring and display verbose differences Many br
-snes_compare_coloring_threshold - Display only those matrix entries that differ by more than a given threshold Many br
-snes_compare_coloring_threshold_atol - Absolute tolerance for difference in matrix entries to be displayed by -snes_compare_coloring_threshold Many br
-snes_compare_coloring_threshold_rtol - Relative tolerance for difference in matrix entries to be displayed by -snes_compare_coloring_threshold Many br
-snes_compare_coloring_draw - Compute the finite differece Jacobian using coloring and draw differences Many br
-snes_compare_coloring_draw_contour - Compute the finite differece Jacobian using coloring and show contours of matrices and differences Many br

Notes

Most users should not need to explicitly call this routine, as it Many bris used internally within the nonlinear solvers. Many br

Many br

Keywords

SNES, compute, Jacobian, matrix

See Also

SNESSetJacobian(), KSPSetOperators(), MatStructure, SNESSetLagPreconditioner(), SNESSetLagJacobian()

Level:developer
Location:
src/snes/interface/snes.c
Index of all SNES routines
Table of Contents for all manual pages
Index of all manual pages

Examples

src/snes/examples/tutorials/ex12.c.html
src/snes/examples/tutorials/ex62.c.html
src/snes/examples/tutorials/ex77.c.html