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
58
59
60
61
62
63
64
65
66
67
68
|
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML3.2 EN">
<HTML>
<HEAD> <link rel="canonical" href="http://www.mcs.anl.gov/petsc/petsc-current/docs/manualpages/TS/TSSetForcingFunction.html" />
<META NAME="GENERATOR" CONTENT="DOCTEXT">
<TITLE>TSSetForcingFunction</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/TS/TSSetForcingFunction.html "><small>Report Typos and Errors</small></a></div>
<A NAME="TSSetForcingFunction"><H1>TSSetForcingFunction</H1></A>
Provide a function that computes a forcing term for a ODE or PDE
<H3><FONT COLOR="#CC3333">Synopsis</FONT></H3>
<PRE>
#include "petscts.h"
<A HREF="../Sys/PetscErrorCode.html#PetscErrorCode">PetscErrorCode</A> <A HREF="../TS/TSSetForcingFunction.html#TSSetForcingFunction">TSSetForcingFunction</A>(<A HREF="../TS/TS.html#TS">TS</A> ts,TSForcingFunction func,void *ctx)
</PRE>
Logically Collective on <A HREF="../TS/TS.html#TS">TS</A>
<P>
<H3><FONT COLOR="#CC3333">Input Parameters</FONT></H3>
<TABLE border="0" cellpadding="0" cellspacing="0">
<TR><TD WIDTH=40></TD><TD ALIGN=LEFT VALIGN=TOP><B>ts </B></TD><TD>- the <A HREF="../TS/TS.html#TS">TS</A> context obtained from <A HREF="../TS/TSCreate.html#TSCreate">TSCreate</A>()
</TD></TR>
<TR><TD WIDTH=40></TD><TD ALIGN=LEFT VALIGN=TOP><B>func </B></TD><TD>- routine for evaluating the forcing function
</TD></TR>
<TR><TD WIDTH=40></TD><TD ALIGN=LEFT VALIGN=TOP><B>ctx </B></TD><TD>- [optional] user-defined context for private data for the
function evaluation routine (may be NULL)
</TD></TR></TABLE>
<P>
<H3><FONT COLOR="#CC3333">Calling sequence of func</FONT></H3>
<pre>
func (<A HREF="../TS/TS.html#TS">TS</A> ts,<A HREF="../Sys/PetscReal.html#PetscReal">PetscReal</A> t,<A HREF="../Vec/Vec.html#Vec">Vec</A> f,void *ctx);
</pre>
<P>
<TABLE border="0" cellpadding="0" cellspacing="0">
<TR><TD WIDTH=40></TD><TD ALIGN=LEFT VALIGN=TOP><B>t </B></TD><TD>- current timestep
</TD></TR>
<TR><TD WIDTH=40></TD><TD ALIGN=LEFT VALIGN=TOP><B>f </B></TD><TD>- output vector
</TD></TR>
<TR><TD WIDTH=40></TD><TD ALIGN=LEFT VALIGN=TOP><B>ctx </B></TD><TD>- [optional] user-defined function context
</TD></TR></TABLE>
<P>
<H3><FONT COLOR="#CC3333">Notes</FONT></H3>
This routine is useful for testing accuracy of time integration schemes when using the Method of Manufactured Solutions to
create closed-form solutions with a non-physical forcing term. It allows you to use the Method of Manufactored Solution without directly editing the
definition of the problem you are solving and hence possibly introducing bugs.
<P>
This replaces the ODE F(u,u_t,t) = 0 the <A HREF="../TS/TS.html#TS">TS</A> is solving with F(u,u_t,t) - func(t) = 0
<P>
This forcing function does not depend on the solution to the equations, it can only depend on spatial location, time, and possibly parameters, the
parameters can be passed in the ctx variable.
<P>
For low-dimensional problems solved in serial, such as small discrete systems, <A HREF="../TS/TSMonitorLGError.html#TSMonitorLGError">TSMonitorLGError</A>() can be used to monitor the error history.
<P>
<P>
<H3><FONT COLOR="#CC3333">Keywords</FONT></H3>
<A HREF="../TS/TS.html#TS">TS</A>, timestep, set, right-hand-side, function
<BR>
<P>
<H3><FONT COLOR="#CC3333">See Also</FONT></H3>
<A HREF="../TS/TSSetRHSJacobian.html#TSSetRHSJacobian">TSSetRHSJacobian</A>(), <A HREF="../TS/TSSetIJacobian.html#TSSetIJacobian">TSSetIJacobian</A>(), <A HREF="../TS/TSComputeSolutionFunction.html#TSComputeSolutionFunction">TSComputeSolutionFunction</A>(), <A HREF="../TS/TSSetSolutionFunction.html#TSSetSolutionFunction">TSSetSolutionFunction</A>()
<BR><P><B></B><H3><FONT COLOR="#CC3333">Level</FONT></H3>beginner<BR>
<H3><FONT COLOR="#CC3333">Location</FONT></H3>
</B><A HREF="../../../src/ts/interface/ts.c.html#TSSetForcingFunction">src/ts/interface/ts.c</A>
<BR><A HREF="./index.html">Index of all TS 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>
|
