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<A NAME="PCSPAISetEpsilon"><H1>PCSPAISetEpsilon</H1></A>
Set the tolerance for the SPAI preconditioner
<H3><FONT COLOR="#CC3333">Synopsis</FONT></H3>
<PRE>
#include "petscpc.h"
int PCSPAISetEpsilon(PC pc,double epsilon1)
</PRE>
<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
</TD></TR>
<TR><TD WIDTH=40></TD><TD ALIGN=LEFT VALIGN=TOP><B>eps </B></TD><TD>- epsilon (default .4)
</TD></TR></TABLE>
<P>
Notes: Espilon must be between 0 and 1. It controls the
quality of the approximation of M to the inverse of
A. Higher values of epsilon lead to more work, more
fill, and usually better preconditioners. In many
cases the best choice of epsilon is the one that
divides the total solution time equally between the
preconditioner and the solver.
<P>
<P>
<H3><FONT COLOR="#CC3333">See Also</FONT></H3>
<A HREF="../PC/PCSPAI.html#PCSPAI">PCSPAI</A>, <A HREF="../PC/PCSetType.html#PCSetType">PCSetType</A>()
<BR><P><B><P><B><FONT COLOR="#CC3333">Level:</FONT></B>intermediate
<BR><FONT COLOR="#CC3333">Location:</FONT></B><A HREF="../../../src/ksp/pc/impls/spai/src/ispai.c.html#PCSPAISetEpsilon">src/ksp/pc/impls/spai/src/ispai.c</A>
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