]> https://gitweb.dealii.org/ - dealii-svn.git/commitdiff
Modified a comment in the Chebyshev preconditioner.
authorkronbichler <kronbichler@0785d39b-7218-0410-832d-ea1e28bc413d>
Tue, 18 Nov 2008 13:26:08 +0000 (13:26 +0000)
committerkronbichler <kronbichler@0785d39b-7218-0410-832d-ea1e28bc413d>
Tue, 18 Nov 2008 13:26:08 +0000 (13:26 +0000)
git-svn-id: https://svn.dealii.org/trunk@17626 0785d39b-7218-0410-832d-ea1e28bc413d

deal.II/lac/include/lac/trilinos_precondition.h

index 7ad20e145aabc99ee07db0b5d0a0fcf16b277735..db81826c6a708db7dfb3b3bff9a744175dc14d93 100755 (executable)
@@ -984,7 +984,11 @@ namespace TrilinosWrappers
        
                                        /**
                                        * This determines the degree of the
-                                       * Chebyshev polynomial.
+                                       * Chebyshev polynomial. The degree
+                                       * of the polynomial gives the number
+                                       * of matrix-vector products to be
+                                       * performed for one application of
+                                       * the vmult() operation.
                                        */
        unsigned int degree;
 
@@ -1021,12 +1025,24 @@ namespace TrilinosWrappers
        double min_diagonal;
 
                                        /**
-                                       * This flag let the preconditioner
-                                       * start at a nonzero value when
-                                       * generating the Chebyshev
-                                       * polynomial.
+                                       * When this flag is set to
+                                       * <tt>true</tt>, it enables the
+                                       * method <tt>vmult(dst, src)</tt> to
+                                       * use non-zero data in the vector
+                                       * <tt>dst</tt>, appending to it the
+                                       * Chebyshev corrections. This can be
+                                       * useful in some situations
+                                       * (e.g. when used for high-frequency
+                                       * error smoothing), but not the way
+                                       * the solver classes expect a
+                                       * preconditioner to work (where one
+                                       * ignores the content in
+                                       * <tt>dst</tt> for the
+                                       * preconditioner application). The
+                                       * user should really know what she
+                                       * is doing when touching this flag.
                                        */
-       double nonzero_starting;
+       bool nonzero_starting;
       };
 
                                        /**

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