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<div id="version" align=right><b>slepc-3.23.1 2025-05-01</b></div>
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<H1>DSSynchronize</H1>
Make sure that all processes have the same data, performing communication if necessary.
<H3><FONT COLOR="#883300">Synopsis</FONT></H3>
<PRE>
#include "slepcds.h"
<A HREF="https://petsc.org/release/manualpages/Sys/PetscErrorCode.html#PetscErrorCode">PetscErrorCode</A> <A HREF="../DS/DSSynchronize.html#DSSynchronize">DSSynchronize</A>(<A HREF="../DS/DS.html#DS">DS</A> ds,<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>
Collective
<P>
<H3><FONT COLOR="#883300">Input Parameter</FONT></H3>
<TABLE border="0" cellpadding="0" cellspacing="0">
<TR><TD WIDTH=40></TD><TD ALIGN=LEFT VALIGN=TOP><B>ds </B></TD><TD> - the direct solver context
</TD></TR></TABLE>
<P>
<H3><FONT COLOR="#883300">Input/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> - (optional) array with the computed eigenvalues (real part)
</TD></TR>
<TR><TD WIDTH=40></TD><TD ALIGN=LEFT VALIGN=TOP><B>eigi </B></TD><TD> - (optional) array with the computed eigenvalues (imaginary part)
</TD></TR></TABLE>
<P>
<H3><FONT COLOR="#883300">Notes</FONT></H3>
When the <A HREF="../DS/DS.html#DS">DS</A> has been created with a communicator with more than one process,
the internal data, especially the computed matrices, may diverge in the
different processes. This happens when using multithreaded BLAS and may
cause numerical issues in some ill-conditioned problems. This function
performs the necessary communication among the processes so that the
internal data is exactly equal in all of them.
<P>
Depending on the parallel mode as set with <A HREF="../DS/DSSetParallel.html#DSSetParallel">DSSetParallel</A>(), this function
will either do nothing or synchronize the matrices computed by <A HREF="../DS/DSSolve.html#DSSolve">DSSolve</A>()
and <A HREF="../DS/DSSort.html#DSSort">DSSort</A>(). The arguments eigr and eigi are typically those used in the
calls to <A HREF="../DS/DSSolve.html#DSSolve">DSSolve</A>() and <A HREF="../DS/DSSort.html#DSSort">DSSort</A>().
<P>
<P>
<H3><FONT COLOR="#883300">See Also</FONT></H3>
<A HREF="../DS/DSSetParallel.html#DSSetParallel">DSSetParallel</A>(), <A HREF="../DS/DSSolve.html#DSSolve">DSSolve</A>(), <A HREF="../DS/DSSort.html#DSSort">DSSort</A>()
<BR><P><B></B><H3><FONT COLOR="#883300">Level</FONT></H3>developer<BR>
<H3><FONT COLOR="#883300">Location</FONT></H3>
</B><A HREF="../../../src/sys/classes/ds/interface/dsops.c.html#DSSynchronize">src/sys/classes/ds/interface/dsops.c</A>
<BR><BR><A HREF="./index.html">Index of all DS routines</A>
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