# TaoSetFromOptions

Sets many TAO_SOLVER parameters from the command line arguments. This command does not set the solver type.

## Synopsis

    #include "tao_solver.h"
    int TaoSetFromOptions(TAO_SOLVER solver)

Collective on TAO_SOLVER

## Input Parameter

solver -the TAO_SOLVER solver context

## Options Database Keys

| -tao_stol | - convergence tolerance in terms of the norm of the change in the solution between steps
| -tao_fatol <fatol> | - absolute tolerance of residual norm
| -tao_frtol <frtol> | - relative decrease in tolerance norm from initial
| -tao_max_its <max_its> | - maximum number of iterations
| -tao_max_funcs <max_funcs> | - maximum number of function evaluations
| -tao_trtol <trtol> | - trust region tolerance
| -tao_trust0 <radius> | - initial trust region radius
| -tao_no_convergence_test | - skip convergence test in minimization solver; hence iterations will continue until max_it or some other criterion is reached. Saves expense of convergence test
| -tao_monitor | - prints residual norm at each iteration
| -tao_vecmonitor | - plots solution at each iteration
| -tao_vecmonitor_update | - plots update to solution at each iteration
| -tao_xmonitor | - plots residual norm at each iteration
| -tao_fd | - use finite differences to compute Hessian; very slow, only for testing
| -tao_mf_ksp_monitor | - if using matrix-free multiply then print h at each KSP iteration

## Notes

To see all options, run your program with the -help option or consult the users manual.

## Keywords

options, converence, monitor, view, database

## See Also

TaoSetMethodFromOptions()

Level:developer
Location:src/interface/newsolver.c
TAO Solver Index
Table of Contents