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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML3.2 EN">
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<TITLE>KSPSetDiagonalScale</TITLE>
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<A NAME="KSPSetDiagonalScale"><H1>KSPSetDiagonalScale</H1></A>
Tells <A HREF="../KSP/KSP.html#KSP">KSP</A> to diagonally scale the system before solving. This actually CHANGES the matrix (and right hand side). 
<H3><FONT COLOR="#CC3333">Synopsis</FONT></H3>
<PRE>
#include "petscksp.h" 
int KSPSetDiagonalScale(KSP ksp,PetscTruth scale)
</PRE>
Collective on <A HREF="../KSP/KSP.html#KSP">KSP</A>
<P>
<H3><FONT COLOR="#CC3333">Input Parameter</FONT></H3>
<TABLE border="0" cellpadding="0" cellspacing="0">
<TR><TD WIDTH=40></TD><TD ALIGN=LEFT VALIGN=TOP><B>ksp </B></TD><TD>- the <A HREF="../KSP/KSP.html#KSP">KSP</A> context
</TD></TR>
<TR><TD WIDTH=40></TD><TD ALIGN=LEFT VALIGN=TOP><B>scale </B></TD><TD>- PETSC_TRUE or PETSC_FALSE
</TD></TR></TABLE>
<P>
<H3><FONT COLOR="#CC3333">Notes</FONT></H3>
BE CAREFUL with this routine: it actually scales the matrix and right
hand side that define the system. After the system is solved the matrix
and right hand side remain scaled.
<P>
This routine is only used if the matrix and preconditioner matrix are
the same thing.
<P>
If you use this with the <A HREF="../PC/PCType.html#PCType">PCType</A> Eisenstat preconditioner than you can
use the <A HREF="../PC/PCEisenstatNoDiagonalScaling.html#PCEisenstatNoDiagonalScaling">PCEisenstatNoDiagonalScaling</A>() option, or -pc_eisenstat_no_diagonal_scaling
to save some unneeded, redundant flops.
<P>

<P>
<H3><FONT COLOR="#CC3333">Keywords</FONT></H3>
 <A HREF="../KSP/KSP.html#KSP">KSP</A>, set, options, prefix, database
<BR>
<P>
<H3><FONT COLOR="#CC3333">See Also</FONT></H3>
 <A HREF="../KSP/KSPGetDiagonalScale.html#KSPGetDiagonalScale">KSPGetDiagonalScale</A>(), <A HREF="../KSP/KSPSetDiagonalScaleFix.html#KSPSetDiagonalScaleFix">KSPSetDiagonalScaleFix</A>()
<BR><P><B><P><B><FONT COLOR="#CC3333">Level:</FONT></B>intermediate
<BR><FONT COLOR="#CC3333">Location:</FONT></B><A HREF="../../../src/ksp/ksp/interface/itfunc.c.html#KSPSetDiagonalScale">src/ksp/ksp/interface/itfunc.c</A>
<BR><A HREF="./index.html">Index of all KSP routines</A>
<BR><A HREF="../../index.html">Table of Contents for all manual pages</A>
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