1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
|
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML3.2 EN">
<HTML>
<HEAD> <link rel="canonical" href="http://www.mcs.anl.gov/petsc/petsc-current/docs/manualpages/KSP/KSPPIPEFCG.html" />
<META NAME="GENERATOR" CONTENT="DOCTEXT">
<TITLE>KSPPIPEFCG</TITLE>
</HEAD>
<BODY BGCOLOR="FFFFFF">
<div id="version" align=right><b>petsc-3.10.3 2018-12-18</b></div>
<div id="bugreport" align=right><a href="mailto:petsc-maint@mcs.anl.gov?subject=Typo or Error in Documentation &body=Please describe the typo or error in the documentation: petsc-3.10.3 v3.10.3 docs/manualpages/KSP/KSPPIPEFCG.html "><small>Report Typos and Errors</small></a></div>
<A NAME="KSPPIPEFCG"><H1>KSPPIPEFCG</H1></A>
Implements a Pipelined, Flexible Conjugate Gradient method.
<H3><FONT COLOR="#CC3333">Options Database Keys</FONT></H3>
<DT><B>-ksp_pipefcg_mmax <N> </B> -The number of previous search directions to store
<br>
<DT><B>-ksp_pipefcg_nprealloc <N> </B> -The number of previous search directions to preallocate
<br>
<DT><B>-ksp_pipefcg_truncation_type <standard,notay> </B> -which stored search directions to orthogonalize against
<br>
<P>
<H3><FONT COLOR="#CC3333">Notes</FONT></H3>
Supports left preconditioning only.
<P>
The natural "norm" for this method is (u,Au), where u is the preconditioned residual. As with standard CG, this norm is available at no additional computational cost. Choosing preconditioned or unpreconditioned norms involve an extra blocking global reduction, thus removing any benefit from pipelining.
<P>
MPI configuration may be necessary for reductions to make asynchronous progress, which is important for performance of pipelined methods.
See the FAQ on the PETSc website for details.
<P>
<H3><FONT COLOR="#CC3333">Reference</FONT></H3>
P. Sanan, S.M. Schnepp, and D.A. May,
"Pipelined, Flexible Krylov Subspace Methods,"
SIAM Journal on Scientific Computing 2016 38:5, C441-C470,
DOI: 10.1137/15M1049130
<P>
<P>
<H3><FONT COLOR="#CC3333">See Also</FONT></H3>
<A HREF="../KSP/KSPFCG.html#KSPFCG">KSPFCG</A>, <A HREF="../KSP/KSPPIPECG.html#KSPPIPECG">KSPPIPECG</A>, <A HREF="../KSP/KSPPIPECR.html#KSPPIPECR">KSPPIPECR</A>, <A HREF="../KSP/KSPGCR.html#KSPGCR">KSPGCR</A>, <A HREF="../KSP/KSPPIPEGCR.html#KSPPIPEGCR">KSPPIPEGCR</A>, <A HREF="../KSP/KSPFGMRES.html#KSPFGMRES">KSPFGMRES</A>, <A HREF="../KSP/KSPCG.html#KSPCG">KSPCG</A>, <A HREF="../KSP/KSPPIPEFCGSetMmax.html#KSPPIPEFCGSetMmax">KSPPIPEFCGSetMmax</A>(), <A HREF="../KSP/KSPPIPEFCGGetMmax.html#KSPPIPEFCGGetMmax">KSPPIPEFCGGetMmax</A>(), <A HREF="../KSP/KSPPIPEFCGSetNprealloc.html#KSPPIPEFCGSetNprealloc">KSPPIPEFCGSetNprealloc</A>(), <A HREF="../KSP/KSPPIPEFCGGetNprealloc.html#KSPPIPEFCGGetNprealloc">KSPPIPEFCGGetNprealloc</A>(), <A HREF="../KSP/KSPPIPEFCGSetTruncationType.html#KSPPIPEFCGSetTruncationType">KSPPIPEFCGSetTruncationType</A>(), <A HREF="../KSP/KSPPIPEFCGGetTruncationType.html#KSPPIPEFCGGetTruncationType">KSPPIPEFCGGetTruncationType</A>()
<BR>
<P>
<P><B></B><H3><FONT COLOR="#CC3333">Level</FONT></H3>intermediate<BR>
<H3><FONT COLOR="#CC3333">Location</FONT></H3>
</B><A HREF="../../../src/ksp/ksp/impls/fcg/pipefcg/pipefcg.c.html#KSPPIPEFCG">src/ksp/ksp/impls/fcg/pipefcg/pipefcg.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>
<BR><A HREF="../singleindex.html">Index of all manual pages</A>
</BODY></HTML>
|
