1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
|
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML3.2 EN">
<HTML>
<HEAD> <link rel="canonical" href="http://www.mcs.anl.gov/petsc/petsc-current/docs/manualpages/PC/PCMGType.html" />
<META NAME="GENERATOR" CONTENT="DOCTEXT">
<TITLE>PCMGType</TITLE>
</HEAD>
<BODY BGCOLOR="FFFFFF">
<div id="version" align=right><b>petsc-3.7.5 2017-01-01</b></div>
<div id="bugreport" align=right><a href="mailto:petsc-maint@mcs.anl.gov?subject=Typo or Error in Documentation &body=Please describe the typo or error in the documentation: petsc-3.7.5 v3.7.5 docs/manualpages/PC/PCMGType.html "><small>Report Typos and Errors</small></a></div>
<A NAME="PCMGType"><H1>PCMGType</H1></A>
Determines the type of multigrid method that is run.
<H3><FONT COLOR="#CC3333">Synopsis</FONT></H3>
<PRE>
typedef enum { PC_MG_MULTIPLICATIVE,PC_MG_ADDITIVE,PC_MG_FULL,PC_MG_KASKADE } <A HREF="../PC/PCMGType.html#PCMGType">PCMGType</A>;
</PRE>
<P>
<H3><FONT COLOR="#CC3333">Values</FONT></H3>
<TABLE border="0" cellpadding="0" cellspacing="0">
<TR><TD WIDTH=40></TD><TD ALIGN=LEFT VALIGN=TOP><B>PC_MG_MULTIPLICATIVE (default) </B></TD><TD>- traditional V or W cycle as determined by PCMGSetCycles()
</TD></TR>
<TR><TD WIDTH=40></TD><TD ALIGN=LEFT VALIGN=TOP><B>PC_MG_ADDITIVE </B></TD><TD>- the additive multigrid preconditioner where all levels are
smoothed before updating the residual. This only uses the
down smoother, in the preconditioner the upper smoother is ignored
</TD></TR>
<TR><TD WIDTH=40></TD><TD ALIGN=LEFT VALIGN=TOP><B>PC_MG_FULL </B></TD><TD>- same as multiplicative except one also performs grid sequencing,
that is starts on the coarsest grid, performs a cycle, interpolates
to the next, performs a cycle etc. This is much like the F-cycle presented in "Multigrid" by Trottenberg, Oosterlee, Schuller page 49, but that
algorithm supports smoothing on before the restriction on each level in the initial restriction to the coarsest stage. In addition that algorithm
calls the V-cycle only on the coarser level and has a post-smoother instead.
</TD></TR>
<TR><TD WIDTH=40></TD><TD ALIGN=LEFT VALIGN=TOP><B>PC_MG_KASKADE </B></TD><TD>- like full multigrid except one never goes back to a coarser level
from a finer
</TD></TR></TABLE>
<P>
<H3><FONT COLOR="#CC3333">See Also</FONT></H3>
<A HREF="../PC/PCMGSetType.html#PCMGSetType">PCMGSetType</A>()
<BR>
<P>
<P><B><P><B><FONT COLOR="#CC3333">Level:</FONT></B>beginner
<BR><FONT COLOR="#CC3333">Location:</FONT></B><A HREF="../../../src/ksp/pc/../../../include/petscpctypes.h.html#PCMGType">src/ksp/pc/../../../include/petscpctypes.h</A>
<BR><A HREF="./index.html">Index of all PC routines</A>
<BR><A HREF="../../index.html">Table of Contents for all manual pages</A>
<BR><A HREF="../singleindex.html">Index of all manual pages</A>
</BODY></HTML>
|
