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
|
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML3.2 EN">
<HTML>
<HEAD> <link rel="canonical" href="https://slepc.upv.es/documentation/current//Users/jroman/tmp/slepc-3.23.1/docs/manualpages/BV/BVMult.html" />
<META NAME="GENERATOR" CONTENT="DOCTEXT">
<link rel="stylesheet" href="/slepc.css" type="text/css">
<TITLE>BVMult</TITLE>
</HEAD>
<BODY BGCOLOR="FFFFFF">
<div id="version" align=right><b>slepc-3.23.1 2025-05-01</b></div>
<div id="bugreport" align=right><a href="mailto:slepc-maint@upv.es?subject=Typo or Error in Documentation &body=Please describe the typo or error in the documentation: slepc-3.23.1 v3.23.1 /Users/jroman/tmp/slepc-3.23.1/docs/manualpages/BV/BVMult.html "><small>Report Typos and Errors</small></a></div>
<H1>BVMult</H1>
Computes Y = beta*Y + alpha*X*Q.
<H3><FONT COLOR="#883300">Synopsis</FONT></H3>
<PRE>
#include "slepcbv.h"
<A HREF="https://petsc.org/release/manualpages/Sys/PetscErrorCode.html#PetscErrorCode">PetscErrorCode</A> <A HREF="../BV/BVMult.html#BVMult">BVMult</A>(<A HREF="../BV/BV.html#BV">BV</A> Y,<A HREF="https://petsc.org/release/manualpages/Sys/PetscScalar.html#PetscScalar">PetscScalar</A> alpha,<A HREF="https://petsc.org/release/manualpages/Sys/PetscScalar.html#PetscScalar">PetscScalar</A> beta,<A HREF="../BV/BV.html#BV">BV</A> X,<A HREF="https://petsc.org/release/manualpages/Mat/Mat.html#Mat">Mat</A> Q)
</PRE>
Logically 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>Y </B></TD><TD> - first basis vectors context (modified on output)
</TD></TR>
<TR><TD WIDTH=40></TD><TD ALIGN=LEFT VALIGN=TOP><B>alpha </B></TD><TD> - first scalar
</TD></TR>
<TR><TD WIDTH=40></TD><TD ALIGN=LEFT VALIGN=TOP><B>beta </B></TD><TD> - second scalar
</TD></TR>
<TR><TD WIDTH=40></TD><TD ALIGN=LEFT VALIGN=TOP><B>X </B></TD><TD> - second basis vectors context
</TD></TR>
<TR><TD WIDTH=40></TD><TD ALIGN=LEFT VALIGN=TOP><B>Q </B></TD><TD> - (optional) sequential dense matrix
</TD></TR></TABLE>
<P>
<H3><FONT COLOR="#883300">Notes</FONT></H3>
X and Y must be different objects. The case X=Y can be addressed with
<A HREF="../BV/BVMultInPlace.html#BVMultInPlace">BVMultInPlace</A>().
<P>
If matrix Q is NULL, then an AXPY operation Y = beta*Y + alpha*X is done
(i.e. results as if Q = identity). If provided,
the matrix Q must be a sequential dense <A HREF="https://petsc.org/release/manualpages/Mat/Mat.html#Mat">Mat</A>, with all entries equal on
all processes (otherwise each process will compute a different update).
The dimensions of Q must be at least m,n where m is the number of active
columns of X and n is the number of active columns of Y.
<P>
The leading columns of Y are not modified. Also, if X has leading
columns specified, then these columns do not participate in the computation.
Hence, only rows (resp. columns) of Q starting from lx (resp. ly) are used,
where lx (resp. ly) is the number of leading columns of X (resp. Y).
<P>
<P>
<H3><FONT COLOR="#883300">See Also</FONT></H3>
<A HREF="../BV/BVMultVec.html#BVMultVec">BVMultVec</A>(), <A HREF="../BV/BVMultColumn.html#BVMultColumn">BVMultColumn</A>(), <A HREF="../BV/BVMultInPlace.html#BVMultInPlace">BVMultInPlace</A>(), <A HREF="../BV/BVSetActiveColumns.html#BVSetActiveColumns">BVSetActiveColumns</A>()
<BR><P><B></B><H3><FONT COLOR="#883300">Level</FONT></H3>intermediate<BR>
<H3><FONT COLOR="#883300">Location</FONT></H3>
</B><A HREF="../../../src/sys/classes/bv/interface/bvops.c.html#BVMult">src/sys/classes/bv/interface/bvops.c</A>
<BR><BR><A HREF="./index.html">Index of all BV routines</A>
<BR><A HREF="../../../docs/manual.html">Table of Contents for all manual pages</A>
<BR><A HREF="../singleindex.html">Index of all manual pages</A>
</BODY></HTML>
|
