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<div id="version" align=right><b>slepc-3.23.1 2025-05-01</b></div>
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<H1>EPSGetEigenvector</H1>
Gets the i-th right eigenvector as computed by <A HREF="../EPS/EPSSolve.html#EPSSolve">EPSSolve</A>().
<H3><FONT COLOR="#883300">Synopsis</FONT></H3>
<PRE>
#include "slepceps.h"
<A HREF="https://petsc.org/release/manualpages/Sys/PetscErrorCode.html#PetscErrorCode">PetscErrorCode</A> <A HREF="../EPS/EPSGetEigenvector.html#EPSGetEigenvector">EPSGetEigenvector</A>(<A HREF="../EPS/EPS.html#EPS">EPS</A> eps,<A HREF="https://petsc.org/release/manualpages/Sys/PetscInt.html#PetscInt">PetscInt</A> i,<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>eps </B></TD><TD> - 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>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>
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 corresponding eigenvalue is real, then Vi is set to zero. If PETSc is
configured with complex scalars the eigenvector is stored
directly 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="../EPS/EPSGetConverged.html#EPSGetConverged">EPSGetConverged</A>()).
Eigenpairs are indexed according to the ordering criterion established
with <A HREF="../EPS/EPSSetWhichEigenpairs.html#EPSSetWhichEigenpairs">EPSSetWhichEigenpairs</A>().
<P>
The 2-norm of the eigenvector is one unless the problem is generalized
Hermitian. In this case the eigenvector is normalized with respect to the
norm defined by the B matrix.
<P>
<P>
<H3><FONT COLOR="#883300">See Also</FONT></H3>
<A HREF="../EPS/EPSSolve.html#EPSSolve">EPSSolve</A>(), <A HREF="../EPS/EPSGetConverged.html#EPSGetConverged">EPSGetConverged</A>(), <A HREF="../EPS/EPSSetWhichEigenpairs.html#EPSSetWhichEigenpairs">EPSSetWhichEigenpairs</A>(), <A HREF="../EPS/EPSGetEigenpair.html#EPSGetEigenpair">EPSGetEigenpair</A>(), <A HREF="../EPS/EPSGetLeftEigenvector.html#EPSGetLeftEigenvector">EPSGetLeftEigenvector</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/eps/interface/epssolve.c.html#EPSGetEigenvector">src/eps/interface/epssolve.c</A>
<P><H3><FONT COLOR="#883300">Examples</FONT></H3>
<A HREF="../../../src/eps/tutorials/ex7.c.html">src/eps/tutorials/ex7.c</A><BR>
<A HREF="../../../src/eps/tutorials/ex47.c.html">src/eps/tutorials/ex47.c</A><BR>
<A HREF="../../../src/eps/tutorials/ex55.c.html">src/eps/tutorials/ex55.c</A><BR>
<BR><BR><A HREF="./index.html">Index of all EPS routines</A>
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