MatFDColoringSetParameters

Synopsis

#include "petscmat.h" 
PetscErrorCode MatFDColoringSetParameters(MatFDColoring matfd,PetscReal error,PetscReal umin)

The Jacobian is estimated with the differencing approximation

       F'(u)_{:,i} = [F(u+h*dx_{i}) - F(u)]/h where
       htype = 'ds':
         h = error_rel*u[i]                 if  abs(u[i]) > umin
           = +/- error_rel*umin             otherwise, with +/- determined by the sign of u[i]
         dx_{i} = (0, ... 1, .... 0)

       htype = 'wp':
         h = error_rel * sqrt(1 + ||u||)

Input Parameters

See Also

Level

Location