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<div id="version" align=right><b>petsc-3.14.5 2021-03-03</b></div>
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<A NAME="SNESNASM"><H1>SNESNASM</H1></A>
Nonlinear Additive Schwarz
<H3><FONT COLOR="#CC3333">Options Database</FONT></H3>
<TABLE border="0" cellpadding="0" cellspacing="0">
<TR><TD WIDTH=40></TD><TD ALIGN=LEFT VALIGN=TOP><B>-snes_nasm_log </B></TD><TD>- enable logging events for the communication and solve stages
</TD></TR>
<TR><TD WIDTH=40></TD><TD ALIGN=LEFT VALIGN=TOP><B>-snes_nasm_type <basic,restrict> </B></TD><TD>- type of subdomain update used
</TD></TR>
<TR><TD WIDTH=40></TD><TD ALIGN=LEFT VALIGN=TOP><B>-snes_asm_damping <dmp> </B></TD><TD>- the new solution is obtained as old solution plus dmp times (sum of the solutions on the subdomains)
</TD></TR>
<TR><TD WIDTH=40></TD><TD ALIGN=LEFT VALIGN=TOP><B>-snes_nasm_finaljacobian </B></TD><TD>- compute the local and global jacobians of the final iterate
</TD></TR>
<TR><TD WIDTH=40></TD><TD ALIGN=LEFT VALIGN=TOP><B>-snes_nasm_finaljacobian_type <finalinner,finalouter,initial> </B></TD><TD>- pick state the jacobian is calculated at
</TD></TR>
<TR><TD WIDTH=40></TD><TD ALIGN=LEFT VALIGN=TOP><B>-sub_snes_ </B></TD><TD>- options prefix of the subdomain nonlinear solves
</TD></TR>
<TR><TD WIDTH=40></TD><TD ALIGN=LEFT VALIGN=TOP><B>-sub_ksp_ </B></TD><TD>- options prefix of the subdomain Krylov solver
</TD></TR>
<TR><TD WIDTH=40></TD><TD ALIGN=LEFT VALIGN=TOP><B>-sub_pc_ </B></TD><TD>- options prefix of the subdomain preconditioner
</TD></TR></TABLE>
<P>
<P>
Developer Note: This is a non-Newton based nonlinear solver that does not directly require a Jacobian; hence the flag snes->usesksp is set to
false and <A HREF="../SNES/SNESView.html#SNESView">SNESView</A>() and -snes_view do not display a <A HREF="../KSP/KSP.html#KSP">KSP</A> object. However, if the flag nasm->finaljacobian is set (for example, if
NASM is used as a nonlinear preconditioner for KSPASPIN) then <A HREF="../SNES/SNESSetUpMatrices.html#SNESSetUpMatrices">SNESSetUpMatrices</A>() is called to generate the Jacobian (needed by KSPASPIN)
and this utilizes the <A HREF="../KSP/KSP.html#KSP">KSP</A> for storing the matrices, but the <A HREF="../KSP/KSP.html#KSP">KSP</A> is never used for solving a linear system. Note that when <A HREF="../SNES/SNESNASM.html#SNESNASM">SNESNASM</A> is
used by <A HREF="../SNES/SNESASPIN.html#SNESASPIN">SNESASPIN</A> they share the same Jacobian matrices because <A HREF="../SNES/SNESSetUp.html#SNESSetUp">SNESSetUp</A>() (called on the outer <A HREF="../SNES/SNES.html#SNES">SNES</A> KSPASPIN) causes the inner <A HREF="../SNES/SNES.html#SNES">SNES</A>
object (in this case <A HREF="../SNES/SNESNASM.html#SNESNASM">SNESNASM</A>) to inherit the outer Jacobian matrices.
<P>
<H3><FONT COLOR="#CC3333">References</FONT></H3>
<TABLE border="0" cellpadding="0" cellspacing="0">
<TR><TD WIDTH=40></TD><TD ALIGN=LEFT VALIGN=TOP><B>1. </B></TD><TD>- Peter R. Brune, Matthew G. Knepley, Barry F. Smith, and Xuemin Tu, "Composing Scalable Nonlinear Algebraic Solvers",
SIAM Review, 57(4), 2015
</TD></TR></TABLE>
<P>
<H3><FONT COLOR="#CC3333">See Also</FONT></H3>
<A HREF="../SNES/SNESCreate.html#SNESCreate">SNESCreate</A>(), <A HREF="../SNES/SNES.html#SNES">SNES</A>, <A HREF="../SNES/SNESSetType.html#SNESSetType">SNESSetType</A>(), <A HREF="../SNES/SNESType.html#SNESType">SNESType</A> (for list of available types), <A HREF="../SNES/SNESNASMSetType.html#SNESNASMSetType">SNESNASMSetType</A>(), <A HREF="../SNES/SNESNASMGetType.html#SNESNASMGetType">SNESNASMGetType</A>(), <A HREF="../SNES/SNESNASMSetSubdomains.html#SNESNASMSetSubdomains">SNESNASMSetSubdomains</A>(), <A HREF="../SNES/SNESNASMGetSubdomains.html#SNESNASMGetSubdomains">SNESNASMGetSubdomains</A>(), <A HREF="../SNES/SNESNASMGetSubdomainVecs.html#SNESNASMGetSubdomainVecs">SNESNASMGetSubdomainVecs</A>(), <A HREF="../SNES/SNESNASMSetComputeFinalJacobian.html#SNESNASMSetComputeFinalJacobian">SNESNASMSetComputeFinalJacobian</A>(), <A HREF="../SNES/SNESNASMSetDamping.html#SNESNASMSetDamping">SNESNASMSetDamping</A>(), <A HREF="../SNES/SNESNASMGetDamping.html#SNESNASMGetDamping">SNESNASMGetDamping</A>()
<BR><P><B></B><H3><FONT COLOR="#CC3333">Level</FONT></H3>advanced<BR>
<H3><FONT COLOR="#CC3333">Location</FONT></H3>
</B><A HREF="../../../src/snes/impls/nasm/nasm.c.html#SNESNASM">src/snes/impls/nasm/nasm.c</A>
<BR><A HREF="./index.html">Index of all SNES routines</A>
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