TaoDefaultComputeGradient#

computes the gradient using finite differences.

Synopsis#

#include "petsctao.h"  
PetscErrorCode TaoDefaultComputeGradient(Tao tao, Vec Xin, Vec G, void *dummy)

Collective

Input Parameters#

tao - the Tao context
Xin - compute gradient at this point
dummy - not used

Output Parameter#

G - Gradient Vector

Options Database Key#

-tao_fd_gradient - activates TaoDefaultComputeGradient()
-tao_fd_delta - change in X used to calculate finite differences

Notes#

This routine is slow and expensive, and is not optimized to take advantage of sparsity in the problem. Although 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. This finite difference gradient evaluation can be set using the routine TaoSetGradient() or by using the command line option -tao_fd_gradient

Level#

advanced

Location#

src/tao/interface/fdiff.c

Index of all Tao routines
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Index of all manual pages