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
|
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML3.2 EN">
<HTML>
<HEAD> <link rel="canonical" href="http://www.mcs.anl.gov/petsc/petsc-current/docs/manualpages/Vec/VecSetOption.html" />
<META NAME="GENERATOR" CONTENT="DOCTEXT">
<TITLE>VecSetOption</TITLE>
</HEAD>
<BODY BGCOLOR="FFFFFF">
<div id="version" align=right><b>petsc-3.10.3 2018-12-18</b></div>
<div id="bugreport" align=right><a href="mailto:petsc-maint@mcs.anl.gov?subject=Typo or Error in Documentation &body=Please describe the typo or error in the documentation: petsc-3.10.3 v3.10.3 docs/manualpages/Vec/VecSetOption.html "><small>Report Typos and Errors</small></a></div>
<A NAME="VecSetOption"><H1>VecSetOption</H1></A>
Sets an option for controling a vector's behavior.
<H3><FONT COLOR="#CC3333">Synopsis</FONT></H3>
<PRE>
#include "petscvec.h"
<A HREF="../Sys/PetscErrorCode.html#PetscErrorCode">PetscErrorCode</A> <A HREF="../Vec/VecSetOption.html#VecSetOption">VecSetOption</A>(<A HREF="../Vec/Vec.html#Vec">Vec</A> x,VecOption op,<A HREF="../Sys/PetscBool.html#PetscBool">PetscBool</A> flag)
</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>x </B></TD><TD>- the vector
</TD></TR>
<TR><TD WIDTH=40></TD><TD ALIGN=LEFT VALIGN=TOP><B>op </B></TD><TD>- the option
</TD></TR>
<TR><TD WIDTH=40></TD><TD ALIGN=LEFT VALIGN=TOP><B>flag </B></TD><TD>- turn the option on or off
</TD></TR></TABLE>
<P>
<H3><FONT COLOR="#CC3333">Supported Options</FONT></H3>
<TABLE border="0" cellpadding="0" cellspacing="0">
<TR><TD WIDTH=40></TD><TD ALIGN=LEFT VALIGN=TOP><B>VEC_IGNORE_OFF_PROC_ENTRIES, which causes <A HREF="../Vec/VecSetValues.html#VecSetValues">VecSetValues</A>() to ignore</B></TD><TD>- entries destined to be stored on a separate processor. This can be used
to eliminate the global reduction in the VecAssemblyXXXX() if you know
that you have only used <A HREF="../Vec/VecSetValues.html#VecSetValues">VecSetValues</A>() to set local elements
</TD></TR>
<TR><TD WIDTH=40></TD><TD ALIGN=LEFT VALIGN=TOP><B>VEC_IGNORE_NEGATIVE_INDICES, which means you can pass negative indices</B></TD><TD>- in ix in calls to <A HREF="../Vec/VecSetValues.html#VecSetValues">VecSetValues</A>() or <A HREF="../Vec/VecGetValues.html#VecGetValues">VecGetValues</A>(). These rows are simply
ignored.
</TD></TR>
<TR><TD WIDTH=40></TD><TD ALIGN=LEFT VALIGN=TOP><B>VEC_SUBSET_OFF_PROC_ENTRIES, which causes <A HREF="../Vec/VecAssemblyBegin.html#VecAssemblyBegin">VecAssemblyBegin</A>() to assume that the off</B></TD><TD>- process
entries will always be a subset (possibly equal) of the off-process entries set on the
first assembly. This reuses the communication pattern, thus avoiding a global reduction.
Subsequent assemblies setting off-process values should use the same <A HREF="../Sys/InsertMode.html#InsertMode">InsertMode</A> as the
first assembly.
</TD></TR></TABLE>
<P>
<H3><FONT COLOR="#CC3333">Developer Note</FONT></H3>
The <A HREF="../Sys/InsertMode.html#InsertMode">InsertMode</A> restriction could be removed by packing the stash messages out of place.
<P>
<P>
<P><B></B><H3><FONT COLOR="#CC3333">Level</FONT></H3>intermediate<BR>
<H3><FONT COLOR="#CC3333">Location</FONT></H3>
</B><A HREF="../../../src/vec/vec/interface/vector.c.html#VecSetOption">src/vec/vec/interface/vector.c</A>
<P><H3><FONT COLOR="CC3333">Implementations</FONT></H3><A HREF="../../../src/vec/vec/impls/mpi/pbvec.c.html#VecSetOption_MPI">VecSetOption_MPI in src/vec/vec/impls/mpi/pbvec.c</A><BR>
<A HREF="../../../src/vec/vec/impls/seq/bvec2.c.html#VecSetOption_Seq">VecSetOption_Seq in src/vec/vec/impls/seq/bvec2.c</A><BR>
<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>
</BODY></HTML>
|
