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
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
|
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML3.2 EN">
<HTML>
<HEAD> <link rel="canonical" href="https://slepc.upv.es/documentation/current/docs/manualpages/PEP/PEPGetEigenpair.html" />
<META NAME="GENERATOR" CONTENT="DOCTEXT">
<link rel="stylesheet" href="/slepc.css" type="text/css">
<TITLE>PEPGetEigenpair</TITLE>
</HEAD>
<BODY BGCOLOR="FFFFFF">
<div id="version" align=right><b>slepc-3.22.2 2024-12-02</b></div>
<div id="bugreport" align=right><a href="mailto:slepc-maint@upv.es?subject=Typo or Error in Documentation &body=Please describe the typo or error in the documentation: slepc-3.22.2 v3.22.2 docs/manualpages/PEP/PEPGetEigenpair.html "><small>Report Typos and Errors</small></a></div>
<H1>PEPGetEigenpair</H1>
Gets the i-th solution of the eigenproblem as computed by <A HREF="../PEP/PEPSolve.html#PEPSolve">PEPSolve</A>(). The solution consists in both the eigenvalue and the eigenvector.
<H3><FONT COLOR="#883300">Synopsis</FONT></H3>
<PRE>
#include "slepcpep.h"
<A HREF="https://petsc.org/release/manualpages/Sys/PetscErrorCode.html#PetscErrorCode">PetscErrorCode</A> <A HREF="../PEP/PEPGetEigenpair.html#PEPGetEigenpair">PEPGetEigenpair</A>(<A HREF="../PEP/PEP.html#PEP">PEP</A> pep,<A HREF="https://petsc.org/release/manualpages/Sys/PetscInt.html#PetscInt">PetscInt</A> i,<A HREF="https://petsc.org/release/manualpages/Sys/PetscScalar.html#PetscScalar">PetscScalar</A> *eigr,<A HREF="https://petsc.org/release/manualpages/Sys/PetscScalar.html#PetscScalar">PetscScalar</A> *eigi,<A HREF="https://petsc.org/release/manualpages/Vec/Vec.html#Vec">Vec</A> Vr,<A HREF="https://petsc.org/release/manualpages/Vec/Vec.html#Vec">Vec</A> Vi)
</PRE>
Collective
<P>
<H3><FONT COLOR="#883300">Input Parameters</FONT></H3>
<TABLE border="0" cellpadding="0" cellspacing="0">
<TR><TD WIDTH=40></TD><TD ALIGN=LEFT VALIGN=TOP><B>pep </B></TD><TD> - polynomial eigensolver context
</TD></TR>
<TR><TD WIDTH=40></TD><TD ALIGN=LEFT VALIGN=TOP><B>i </B></TD><TD> - index of the solution
</TD></TR></TABLE>
<P>
<H3><FONT COLOR="#883300">Output Parameters</FONT></H3>
<TABLE border="0" cellpadding="0" cellspacing="0">
<TR><TD WIDTH=40></TD><TD ALIGN=LEFT VALIGN=TOP><B>eigr </B></TD><TD> - real part of eigenvalue
</TD></TR>
<TR><TD WIDTH=40></TD><TD ALIGN=LEFT VALIGN=TOP><B>eigi </B></TD><TD> - imaginary part of eigenvalue
</TD></TR>
<TR><TD WIDTH=40></TD><TD ALIGN=LEFT VALIGN=TOP><B>Vr </B></TD><TD> - real part of eigenvector
</TD></TR>
<TR><TD WIDTH=40></TD><TD ALIGN=LEFT VALIGN=TOP><B>Vi </B></TD><TD> - imaginary part of eigenvector
</TD></TR></TABLE>
<P>
<H3><FONT COLOR="#883300">Notes</FONT></H3>
It is allowed to pass NULL for Vr and Vi, if the eigenvector is not
required. Otherwise, the caller must provide valid <A HREF="https://petsc.org/release/manualpages/Vec/Vec.html#Vec">Vec</A> objects, i.e.,
they must be created by the calling program with e.g. <A HREF="https://petsc.org/release/manualpages/Mat/MatCreateVecs.html#MatCreateVecs">MatCreateVecs</A>().
<P>
If the eigenvalue is real, then eigi and Vi are set to zero. If PETSc is
configured with complex scalars the eigenvalue is stored
directly in eigr (eigi is set to zero) and the eigenvector in Vr (Vi is
set to zero). In any case, the user can pass NULL in Vr or Vi if one of
them is not required.
<P>
The index i should be a value between 0 and nconv-1 (see <A HREF="../PEP/PEPGetConverged.html#PEPGetConverged">PEPGetConverged</A>()).
Eigenpairs are indexed according to the ordering criterion established
with <A HREF="../PEP/PEPSetWhichEigenpairs.html#PEPSetWhichEigenpairs">PEPSetWhichEigenpairs</A>().
<P>
<P>
<H3><FONT COLOR="#883300">See Also</FONT></H3>
<A HREF="../PEP/PEPSolve.html#PEPSolve">PEPSolve</A>(), <A HREF="../PEP/PEPGetConverged.html#PEPGetConverged">PEPGetConverged</A>(), <A HREF="../PEP/PEPSetWhichEigenpairs.html#PEPSetWhichEigenpairs">PEPSetWhichEigenpairs</A>()
<BR><P><B></B><H3><FONT COLOR="#883300">Level</FONT></H3>beginner<BR>
<H3><FONT COLOR="#883300">Location</FONT></H3>
</B><A HREF="../../../src/pep/interface/pepsolve.c.html#PEPGetEigenpair">src/pep/interface/pepsolve.c</A>
<P><H3><FONT COLOR="#883300">Examples</FONT></H3>
<A HREF="../../../src/pep/tutorials/ex16.c.html">src/pep/tutorials/ex16.c</A><BR>
<A HREF="../../../src/pep/tutorials/ex40.c.html">src/pep/tutorials/ex40.c</A><BR>
<BR><BR><A HREF="./index.html">Index of all PEP routines</A>
<BR><A HREF="../../../docs/manual.html">Table of Contents for all manual pages</A>
<BR><A HREF="../singleindex.html">Index of all manual pages</A>
</BODY></HTML>
|
