From: bangerth Date: Fri, 21 Mar 2014 01:56:03 +0000 (+0000) Subject: Clarify some language. X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=843844ffb9c127d09579a5e0c590824c993f59b0;p=dealii-svn.git Clarify some language. git-svn-id: https://svn.dealii.org/trunk@32678 0785d39b-7218-0410-832d-ea1e28bc413d --- diff --git a/deal.II/doc/external-libs/petsc.html b/deal.II/doc/external-libs/petsc.html index 43b57575ec..3230d590f5 100644 --- a/deal.II/doc/external-libs/petsc.html +++ b/deal.II/doc/external-libs/petsc.html @@ -4,7 +4,7 @@ The deal.II Readme on interfacing to PETSc - + @@ -44,15 +44,20 @@

- PETSc usually requires you to set the + When you compile and install PETSc, you need to set environment variables PETSC_DIR and PETSC_ARCH to a path to PETSc and denoting the architecture for which PETSc is - compiled (a string you can choose however you like, it is simply - intended to identify one of possibly several different PETSc - installations). If these environment variables are set, then - deal.II will pick them up during - configuration, and store them. It will then also recognize that - PETSc shall be used, and enable the wrapper classes. + compiled. PETSC_ARCH is in reality just a name you give to + your installation, it is a string you can choose however you like. The + point of it is that it allows you to have multiple possibly different + PETSc installations. A consequence of this is that you need to + let deal.II's cmake scripts know which + one of these installations you want it to use, i.e., you need to set the + PETSC_ARCH variable to the same value you used when you + installed PETSc. The same is true for PETSC_DIR. You can + this via environment variables. cmake will then also + recognize that PETSc shall be used, and enable the wrapper classes, + without you having to explicitly say that you want to use PETSc.