[petsc-dev] MatSetFromOptions and help

[Smith, Barry F.]

> On Sep 9, 2018, at 4:54 AM, Stefano Zampini <stefano.zampini at gmail.com> wrote:
> 
> I just noticed a strange behaviour in master. Take mat/examples/ex1.c 

   There is no such example and the examples in the tutorials and tests subdirectories don't work with the given arguments so where is this example?


> 
> ./ex1 -h -mat_type mpiaij 
> 
> does not print the help for the specific MPIAIJ options, only the MPIAIJ options header
> 
> ....
> Matrix (Mat) options -------------------------------------------------
>   -mat_block_size <-1>: Set the blocksize used to store the matrix (MatSetBlockSize)
>   -mat_type <aij>: Matrix type (one of) mffd mpimaij seqmaij maij is shell composite mpiaij seqaij mpiaijperm seqaijperm seqaijcrl mpiaijcrl mpibaij seqbaij mpisbaij seqsbaij mpidense seqdense mpiadj scatter blockmat nest mpisell seqsell preallocator dummy hypre (MatSetType)
>   -mat_is_symmetric: Checks if mat is symmetric on MatAssemblyEnd() (MatIsSymmetric)
>   -mat_is_symmetric <0.>: Checks if mat is symmetric on MatAssemblyEnd() (MatIsSymmetric)
>   -mat_null_space_test: <FALSE> Checks if provided null space is correct in MatAssemblyEnd() (MatSetNullSpaceTest)
>   MPIAIJ options
>   -mat_new_nonzero_location_err: <FALSE> Generate an error if new nonzeros are created in the matrix structure (useful to test preallocation) (MatSetOption)
> 
> Instead, if you run e.g. MFFD, it works 
> 
> Matrix (Mat) options -------------------------------------------------
>   -mat_block_size <-1>: Set the blocksize used to store the matrix (MatSetBlockSize)
>   -mat_type <aij>: Matrix type (one of) mffd mpimaij seqmaij maij is shell composite mpiaij seqaij mpiaijperm seqaijperm seqaijcrl mpiaijcrl mpibaij seqbaij mpisbaij seqsbaij mpidense seqdense mpiadj scatter blockmat nest mpisell seqsell preallocator dummy hypre (MatSetType)
>   -mat_is_symmetric: Checks if mat is symmetric on MatAssemblyEnd() (MatIsSymmetric)
>   -mat_is_symmetric <0.>: Checks if mat is symmetric on MatAssemblyEnd() (MatIsSymmetric)
>   -mat_null_space_test: <FALSE> Checks if provided null space is correct in MatAssemblyEnd() (MatSetNullSpaceTest)
> Matrix-free Finite Differencing (MatMFFD) options -------------------------------------------------
>   -mat_mffd_type <(null)>: Matrix free type (one of) ds wp (MatMFFDSetType)
>   -mat_mffd_err <1.49012e-08>: set sqrt relative error in function (MatMFFDSetFunctionError)
>   -mat_mffd_period <1>: how often h is recomputed (MatMFFDSetPeriod)
>   -mat_mffd_check_positivity: <FALSE> Insure that U + h*a is nonnegative (MatMFFDSetCheckh)
>   -mat_new_nonzero_location_err: <FALSE> Generate an error if new nonzeros are created in the matrix structure (useful to test preallocation) (MatSetOption)
>   -mat_new_nonzero_allocation_err: <FALSE> Generate an error if new nonzeros are allocated in the matrix structure (useful to test preallocation) (MatSetOption)
> 
> What is the proper fix? remove the PetscOptionsBegin call and replace PetscOptionsEnd() with PetscOptionsTail()?
> 
> -- 
> Stefano