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<div id="version" align=right><b>slepc-3.23.1 2025-05-01</b></div>
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<H1>EPSGetEigenvalue</H1>
Gets the i-th eigenvalue 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/EPSGetEigenvalue.html#EPSGetEigenvalue">EPSGetEigenvalue</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/Sys/PetscScalar.html#PetscScalar">PetscScalar</A> *eigr,<A HREF="https://petsc.org/release/manualpages/Sys/PetscScalar.html#PetscScalar">PetscScalar</A> *eigi)
</PRE>
Not 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>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></TABLE>
<P>
<H3><FONT COLOR="#883300">Notes</FONT></H3>
If the eigenvalue is real, then eigi is set to zero. If PETSc is
configured with complex scalars the eigenvalue is stored
directly in eigr (eigi is set to zero).
<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>
<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>()
<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#EPSGetEigenvalue">src/eps/interface/epssolve.c</A>
<P><H3><FONT COLOR="#883300">Examples</FONT></H3>
<A HREF="../../../src/svd/tutorials/cnetwork/embedgsvd.c.html">src/svd/tutorials/cnetwork/embedgsvd.c</A><BR>
<BR><BR><A HREF="./index.html">Index of all EPS routines</A>
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