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<div id="version" align=right><b>petsc-3.10.3 2018-12-18</b></div>
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<A NAME="PCGAMGSetSquareGraph"><H1>PCGAMGSetSquareGraph</H1></A>
Square the graph, ie. compute A'*A before aggregating it
<H3><FONT COLOR="#CC3333">Synopsis</FONT></H3>
<PRE>
#include "petscpc.h"
<A HREF="../Sys/PetscErrorCode.html#PetscErrorCode">PetscErrorCode</A> <A HREF="../PC/PCGAMGSetSquareGraph.html#PCGAMGSetSquareGraph">PCGAMGSetSquareGraph</A>(<A HREF="../PC/PC.html#PC">PC</A> pc, <A HREF="../Sys/PetscInt.html#PetscInt">PetscInt</A> n)
</PRE>
Not Collective on <A HREF="../PC/PC.html#PC">PC</A>
<P>
<H3><FONT COLOR="#CC3333">Input Parameters</FONT></H3>
<TABLE border="0" cellpadding="0" cellspacing="0">
<TR><TD WIDTH=40></TD><TD ALIGN=LEFT VALIGN=TOP><B>pc </B></TD><TD>- the preconditioner context
</TD></TR>
<TR><TD WIDTH=40></TD><TD ALIGN=LEFT VALIGN=TOP><B>n </B></TD><TD>- <A HREF="../Sys/PETSC_TRUE.html#PETSC_TRUE">PETSC_TRUE</A> or <A HREF="../Sys/PETSC_FALSE.html#PETSC_FALSE">PETSC_FALSE</A>
</TD></TR></TABLE>
<P>
<H3><FONT COLOR="#CC3333">Options Database Key</FONT></H3>
<DT><B>-pc_gamg_square_graph <n,default = 1> </B> -number of levels to square the graph on before aggregating it
<br>
<P>
<H3><FONT COLOR="#CC3333">Notes</FONT></H3>
Squaring the graph increases the rate of coarsening (aggressive coarsening) and thereby reduces the complexity of the coarse grids, and generally results in slower solver converge rates. Reducing coarse grid complexity reduced the complexity of Galerkin coarse grid construction considerably.
<P>
<P>
<P>
<H3><FONT COLOR="#CC3333">See Also</FONT></H3>
<A HREF="../PC/PCGAMGSetSymGraph.html#PCGAMGSetSymGraph">PCGAMGSetSymGraph</A>(), <A HREF="../PC/PCGAMGSetThreshold.html#PCGAMGSetThreshold">PCGAMGSetThreshold</A>()
<BR><P><B></B><H3><FONT COLOR="#CC3333">Level</FONT></H3>intermediate<BR>
<H3><FONT COLOR="#CC3333">Location</FONT></H3>
</B><A HREF="../../../src/ksp/pc/impls/gamg/agg.c.html#PCGAMGSetSquareGraph">src/ksp/pc/impls/gamg/agg.c</A>
<P><H3><FONT COLOR="CC3333">Implementations</FONT></H3><A HREF="../../../src/ksp/pc/impls/gamg/agg.c.html#PCGAMGSetSquareGraph_AGG">PCGAMGSetSquareGraph_AGG in src/ksp/pc/impls/gamg/agg.c</A><BR>
<BR><A HREF="./index.html">Index of all PC routines</A>
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