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<div id="version" align=right><b>petsc-3.4.2 2013-07-02</b></div>
<A NAME="TSAlphaSetRadius"><H1>TSAlphaSetRadius</H1></A>
sets the desired spectral radius of the method (i.e. high-frequency numerical damping)
<H3><FONT COLOR="#CC3333">Synopsis</FONT></H3>
<PRE>
#include "petscts.h"
PetscErrorCode TSAlphaSetRadius(TS ts,PetscReal radius)
</PRE>
Logically Collective on <A HREF="../TS/TS.html#TS">TS</A>
<P>
The algorithmic parameters \alpha_m and \alpha_f of the
generalized-\alpha method can be computed in terms of a specified
spectral radius \rho in [0,1] for infinite time step in order to
<H3><FONT COLOR="#CC3333">control high-frequency numerical damping</FONT></H3>
alpha_m = 0.5*(3-\rho)/(1+\rho)
alpha_f = 1/(1+\rho)
<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>ts </B></TD><TD>- timestepping context
</TD></TR>
<TR><TD WIDTH=40></TD><TD ALIGN=LEFT VALIGN=TOP><B>radius </B></TD><TD>- the desired spectral radius
</TD></TR></TABLE>
<P>
<H3><FONT COLOR="#CC3333">Options Database</FONT></H3>
<DT><B>-ts_alpha_radius <radius></B> -
<br>
<P>
<H3><FONT COLOR="#CC3333">See Also</FONT></H3>
<A HREF="../TS/TSAlphaSetParams.html#TSAlphaSetParams">TSAlphaSetParams</A>(), <A HREF="../TS/TSAlphaGetParams.html#TSAlphaGetParams">TSAlphaGetParams</A>()
<BR><P><B><P><B><FONT COLOR="#CC3333">Level:</FONT></B>intermediate
<BR><FONT COLOR="#CC3333">Location:</FONT></B><A HREF="../../../src/ts/impls/implicit/alpha/alpha.c.html#TSAlphaSetRadius">src/ts/impls/implicit/alpha/alpha.c</A>
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