petsc-3.7.5 2017-01-01
TaoDefaultComputeGradient
computes the gradient using finite differences.
Synopsis
#include "petsctao.h"
PetscErrorCode TaoDefaultComputeGradient(Tao tao,Vec X,Vec G,void *dummy)
Collective on Tao
Input Parameters
| tao | - the Tao context
|
| X | - compute gradient at this point
|
| dummy | - not used
|
Output Parameters
G -Gradient Vector
Options Database Key
| -tao_fd_gradient | - Activates TaoDefaultComputeGradient()
|
| -tao_fd_delta <delta> | - change in x used to calculate finite differences
|
Note
This routine is slow and expensive, and is not currently optimized
to take advantage of sparsity in the problem. Although
TaoAppDefaultComputeGradient is not recommended for general use
in large-scale applications, It can be useful in checking the
correctness of a user-provided gradient. Use the tao method TAOTEST
to get an indication of whether your gradient is correct.
Note
This finite difference gradient evaluation can be set using the routine TaoSetGradientRoutine() or by using the command line option -tao_fd_gradient
See Also
TaoSetGradientRoutine()
Level:advanced
Location:src/tao/interface/fdiff.c
Index of all Tao routines
Table of Contents for all manual pages
Index of all manual pages