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<A NAME="VecStrideGather"><H1>VecStrideGather</H1></A>
Gathers a single component from a multi-component vector into another vector.
<H3><FONT COLOR="#CC3333">Synopsis</FONT></H3>
<PRE>
#include "petscvec.h"
int VecStrideGather(Vec v,int start,Vec s,InsertMode addv)
</PRE>
Collective on <A HREF="../Vec/Vec.html#Vec">Vec</A>
<P>
<H3><FONT COLOR="#CC3333">Input Parameter</FONT></H3>
<TABLE border="0" cellpadding="0" cellspacing="0">
<TR><TD WIDTH=40></TD><TD ALIGN=LEFT VALIGN=TOP><B>v </B></TD><TD>- the vector
</TD></TR>
<TR><TD WIDTH=40></TD><TD ALIGN=LEFT VALIGN=TOP><B>start </B></TD><TD>- starting point of the subvector (defined by a stride)
</TD></TR>
<TR><TD WIDTH=40></TD><TD ALIGN=LEFT VALIGN=TOP><B>addv </B></TD><TD>- one of ADD_VALUES,INSERT_VALUES,MAX_VALUES
</TD></TR></TABLE>
<P>
<H3><FONT COLOR="#CC3333">Output Parameter</FONT></H3>
<DT><B>s </B> -the location where the subvector is stored
<br>
<P>
<H3><FONT COLOR="#CC3333">Notes</FONT></H3>
One must call <A HREF="../Vec/VecSetBlockSize.html#VecSetBlockSize">VecSetBlockSize</A>() before this routine to set the stride
information, or use a vector created from a multicomponent <A HREF="../DA/DA.html#DA">DA</A>.
<P>
If x is the array representing the vector x then this gathers
the array (x[start],x[start+stride],x[start+2*stride], ....)
<P>
The parallel layout of the vector and the subvector must be the same;
i.e., nlocal of v = stride*(nlocal of s)
<P>
Not optimized; could be easily
<P>
<P>
<P>
<H3><FONT COLOR="#CC3333">See Also</FONT></H3>
<A HREF="../Vec/VecStrideNorm.html#VecStrideNorm">VecStrideNorm</A>(), <A HREF="../Vec/VecStrideScatter.html#VecStrideScatter">VecStrideScatter</A>(), <A HREF="../Vec/VecStrideMin.html#VecStrideMin">VecStrideMin</A>(), <A HREF="../Vec/VecStrideMax.html#VecStrideMax">VecStrideMax</A>(), <A HREF="../Vec/VecStrideGatherAll.html#VecStrideGatherAll">VecStrideGatherAll</A>(),
<BR><A HREF="../Vec/VecStrideScatterAll.html#VecStrideScatterAll">VecStrideScatterAll</A>()
<P><B><P><B><FONT COLOR="#CC3333">Level:</FONT></B>advanced
<BR><FONT COLOR="#CC3333">Location:</FONT></B><A HREF="../../../src/vec/utils/vinv.c.html#VecStrideGather">src/vec/utils/vinv.c</A>
<BR><A HREF="./index.html">Index of all Vec 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>
<P><H3><FONT COLOR="#CC3333">Examples</FONT></H3>
<A HREF="../../../src/vec/examples/tutorials/ex12.c.html">src/vec/examples/tutorials/ex12.c.html</A><BR>
<A HREF="../../../src/vec/examples/tutorials/ex16.c.html">src/vec/examples/tutorials/ex16.c.html</A><BR>
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