> On Jun 26, 2016, at 8:30 PM, Adrian Croucher <[email protected]> > wrote: > > hi > > Sorry, I realise now I was barking up the wrong tree in trying to use > MatMFFDSetType(). > > What I'm actually looking for is just the equivalent of setting the command > line option "-mat_fd_type ds" as default in my code- for an ordinary Jacobian > matrix, not for a matrix-free method. > > The doc page on MatFDColoringSetFromOptions(): > > http://www.mcs.anl.gov/petsc/petsc-current/docs/manualpages/MatFD/MatFDColoringSetFromOptions.html > > mentions setting the fd type to 'wp' or 'ds', and links to pages about > MATMFFD_WP and MATMFFD_DS, which is probably where I started going astray. > > > How do I do the equivalent of setting the option "-mat_fd_type ds" in my > code? There is MatMFFDSetType() for MATMFFD, but doesn't seem to be anything > like a plain MatFDSetType().
Yes, you are correct, there is no MatFDSetType() and in the SetFromOptions we totally cheat http://www.mcs.anl.gov/petsc/petsc-current/src/mat/matfd/fdmatrix.c.html#MatFDColoringSetFromOptions and just stick the value directly into the data structure. For now you can call PetscOptionsSetValue(NULL,"-mat_fd_type","ds") in your code (before you start using the MatFD stuff) and we'll add the routine to the master branch. Barry I didn't think anyone would care about the difference between ds and wp with MatFD. > > - Adrian > -- > Dr Adrian Croucher > Senior Research Fellow > Department of Engineering Science > University of Auckland, New Zealand > email: > [email protected] > > tel: +64 (0)9 923 84611 >
