petsc-3.7.1 2016-05-15
SNESObjectiveComputeFunctionDefaultFD
Computes the gradient of a user provided objective
Synopsis
PetscErrorCode SNESObjectiveComputeFunctionDefaultFD(SNES snes,Vec X,Vec F,void *ctx)
Collective on SNES Many br
Input Parameter
| snes | - the SNES context Many br |
| X | - the state vector Many br |
| ctx | - the (ignored) function context Many br |
Output Parameter
F -the function value Many br
Options Database Key
| -snes_fd_function_eps | - The differencing parameter Many br |
| -snes_fd_function | - Compute function from user provided objective with finite difference Many br |
Notes
SNESObjectiveComputeFunctionDefaultFD is similar in character to SNESComputeJacobianDefault. Many brTherefore, it should be used for debugging purposes only. Using it in conjunction with Many brSNESComputeJacobianDefault is excessively costly and produces a Jacobian that is quite Many brnoisy. This is often necessary, but should be done with a grain of salt, even when debugging Many brsmall problems. Many br
Note that this uses quadratic interpolation of the objective to form each value in the function. Many br
Many br
Keywords
SNES, objective, debugging, finite differences, function
See Also
SNESSetFunction(), SNESComputeObjective(), SNESComputeJacobianDefault()
Level:advanced
Location:src/snes/interface/snesob.c
Index of all SNES routines
Table of Contents for all manual pages
Index of all manual pages