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
69
70
71
72
73
74
75
76
77
78
79
80
81
82
|
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN">
<!--Converted with LaTeX2HTML 98.2 beta6 (August 14th, 1998)
original version by: Nikos Drakos, CBLU, University of Leeds
* revised and updated by: Marcus Hennecke, Ross Moore, Herb Swan
* with significant contributions from:
Jens Lippmann, Marek Rouchal, Martin Wilck and others -->
<HTML>
<HEAD>
<TITLE>LWORK Query</TITLE>
<META NAME="description" CONTENT="LWORK Query">
<META NAME="keywords" CONTENT="lug_l2h">
<META NAME="resource-type" CONTENT="document">
<META NAME="distribution" CONTENT="global">
<META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=iso-8859-1">
<LINK REL="STYLESHEET" HREF="lug_l2h.css">
<LINK REL="next" HREF="node119.html">
<LINK REL="previous" HREF="node117.html">
<LINK REL="up" HREF="node110.html">
<LINK REL="next" HREF="node119.html">
</HEAD>
<BODY >
<!--Navigation Panel-->
<A NAME="tex2html5873"
HREF="node119.html">
<IMG WIDTH="37" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="next"
SRC="next_motif.png"></A>
<A NAME="tex2html5867"
HREF="node110.html">
<IMG WIDTH="26" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="up"
SRC="up_motif.png"></A>
<A NAME="tex2html5861"
HREF="node117.html">
<IMG WIDTH="63" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="previous"
SRC="previous_motif.png"></A>
<A NAME="tex2html5869"
HREF="node1.html">
<IMG WIDTH="65" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="contents"
SRC="contents_motif.png"></A>
<A NAME="tex2html5871"
HREF="node152.html">
<IMG WIDTH="43" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="index"
SRC="index_motif.png"></A>
<BR>
<B> Next:</B> <A NAME="tex2html5874"
HREF="node119.html">Error Handling and the</A>
<B> Up:</B> <A NAME="tex2html5868"
HREF="node110.html">Design and Documentation of</A>
<B> Previous:</B> <A NAME="tex2html5862"
HREF="node117.html">Work Arrays</A>
  <B> <A NAME="tex2html5870"
HREF="node1.html">Contents</A></B>
  <B> <A NAME="tex2html5872"
HREF="node152.html">Index</A></B>
<BR>
<BR>
<!--End of Navigation Panel-->
<H2><A NAME="SECTION03518000000000000000"></A> <A NAME="lworkquery"></A>
<BR>
LWORK Query
</H2>
If in doubt about the amount of workspace to supply to an LAPACK
routine, the user may choose to supply <B><I>LWORK</I>=-1</B><A NAME="19559"></A>
and use the returned value in <B><I>WORK</I>(1)</B> as the correct value
for <B><I>LWORK</I></B>. Setting <B><I>LWORK</I>=-1</B> does not invoke an error message
from <TT>XERBLA</TT> and is defined as a global
query<A NAME="19561"></A><A NAME="19562"></A><A NAME="19563"></A>.
<P>
The routines xGEESX and xGGESX are the only exceptions to this rule.
For these routines, the value of LWORK is dependent upon the dimension
of the invariant subspace (SDIM), and is not known on entry to the routine.
<P>
<BR><HR>
<ADDRESS>
<I>Susan Blackford</I>
<BR><I>1999-10-01</I>
</ADDRESS>
</BODY>
</HTML>
|
