I'm installing PETSc for complex numbers with the C99 standard. I'd like to have it installed using a higher precision than the default (double, I presume) since that will most likely make the LU preconditioner run better. I've tried several different commands that I could google, but it doesn't work. I've searched the manual but haven't found anything on the subject.
I tried invoking ./configure with the
precision=longdobule
and
precision=__float128
with
download-f-blas-lapack
and
download-f2cblaslapack
in all four different combinations. The one time I used download-f2cblaslapack and precision=__float128 it did configure successfully but at the next stage when I compiled the libraries I got the following error for every library being compiled:
error: unknown type name ‘PetscScalar’
What do I have to write to have it configured at a higher precision?
--with-precision=__float128 --download-f2cblaslapack(as suggested by the PETSc documentation here). – Aron Ahmadia Aug 02 '12 at 12:57