TaoTermComputeGradientFD

Approximate the gradient of a TaoTerm using finite differences

Synopsis

#include "petsctao.h" 
PetscErrorCode TaoTermComputeGradientFD(TaoTerm term, Vec x, Vec params, Vec g)

Collective

Input Parameters

• term - a TaoTerm

• x - a solution vector

• params - parameters vector (may be NULL, see TaoTermParametersMode)

Output Parameter

• g - the computed finite difference approximation to the gradient

Options Database Keys

• -tao_term_fd_delta - change in x used to calculate finite differences

• -tao_term_gradient_use_fd - Use TaoTermComputeGradientFD() in TaoTermComputeGradient()

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. Call TaoTermComputeGradientSetUseFD() to start using this routine in TaoTermComputeGradient().

See Also

TaoTerm: composable objective function terms, TaoTerm, TaoTermGetFDDelta(), TaoTermSetFDDelta(), TaoTermComputeGradientSetUseFD(), TaoTermComputeGradientGetUseFD(), TaoTermComputeHessianFD()

Level

advanced

Location

src/tao/term/utils/taotermfdiff.c

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Index of all TaoTerm routines
Table of Contents for all manual pages
Index of all manual pages