From: Luca Heltai <luca.heltai@sissa.it>
Date: Thu, 22 Dec 2022 08:29:44 +0000 (+0100)
Subject: Improve documentation.
X-Git-Tag: v9.5.0-rc1~611^2~2
X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=6102c6b3a2442b1b45aa1ee0aec75c8a117eb8d1;p=dealii.git

Improve documentation.
---

diff --git a/include/deal.II/lac/petsc_block_sparse_matrix.h b/include/deal.II/lac/petsc_block_sparse_matrix.h
index 626974e70a..15db6f4f31 100644
--- a/include/deal.II/lac/petsc_block_sparse_matrix.h
+++ b/include/deal.II/lac/petsc_block_sparse_matrix.h
@@ -296,6 +296,11 @@ namespace PETScWrappers
 
       /**
        * This method assigns the PETSc Mat to the instance of the class.
+       *
+       * Note that the matrix is not copied: instead, the instance of this class
+       * is initialized to use the given matrix. This is useful if you want to
+       * interpret a PETSc Mat object as a deal.II BlockMatrix, and you already
+       * have a BlockMatrix object that you want to use for this purpose.
        */
       void
       assign_petsc_matrix(Mat A);