<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN">

<!--Converted with LaTeX2HTML 2008 (1.71)
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>psb_spall -- Allocates a sparse matrix</TITLE>
<META NAME="description" CONTENT="psb_spall -- Allocates a sparse matrix">
<META NAME="keywords" CONTENT="userhtml">
<META NAME="resource-type" CONTENT="document">
<META NAME="distribution" CONTENT="global">

<META NAME="Generator" CONTENT="LaTeX2HTML v2008">
<META HTTP-EQUIV="Content-Style-Type" CONTENT="text/css">

<LINK REL="STYLESHEET" HREF="userhtml.css">

<LINK REL="next" HREF="node52.html">
<LINK REL="previous" HREF="node50.html">
<LINK REL="up" HREF="node44.html">
<LINK REL="next" HREF="node52.html">
</HEAD>

<BODY >
<!--Navigation Panel-->
<A NAME="tex2html829"
  HREF="node52.html">
<IMG WIDTH="37" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="next" SRC="next.png"></A> 
<A NAME="tex2html825"
  HREF="node44.html">
<IMG WIDTH="26" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="up" SRC="up.png"></A> 
<A NAME="tex2html819"
  HREF="node50.html">
<IMG WIDTH="63" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="previous" SRC="prev.png"></A> 
<A NAME="tex2html827"
  HREF="node1.html">
<IMG WIDTH="65" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="contents" SRC="contents.png"></A>  
<BR>
<B> Next:</B> <A NAME="tex2html830"
  HREF="node52.html">psb_spins   Insert</A>
<B> Up:</B> <A NAME="tex2html826"
  HREF="node44.html">Data management routines</A>
<B> Previous:</B> <A NAME="tex2html820"
  HREF="node50.html">psb_cdbldext   Build</A>
 &nbsp; <B>  <A NAME="tex2html828"
  HREF="node1.html">Contents</A></B> 
<BR>
<BR>
<!--End of Navigation Panel-->

<H2><A NAME="SECTION00077000000000000000">
psb_spall -- Allocates a sparse matrix</A>
</H2>

<P>
<PRE>
call psb_spall(a, desc_a, info, nnz)
</PRE>

<P>
<DL>
<DT><STRONG>Type:</STRONG></DT>
<DD>Synchronous.
</DD>
<DT><STRONG><B>On Entry</B></STRONG></DT>
<DD>
</DD>
<DT><STRONG>desc_a</STRONG></DT>
<DD>the communication descriptor.
<BR>
Scope:<B>local</B>.
<BR>
Type:<B>required</B>.
<BR>
Intent: <B>in</B>.
<BR>
Specified as: a structured data of type descdata<TT>psb_desc_type</TT>.
</DD>
<DT><STRONG>nnz</STRONG></DT>
<DD>An estimate of the number of nonzeroes in the local
  part of the assembled matrix.
<BR>
Scope: <B>global</B>.
<BR>
Type: <B>optional</B>.
<BR>
Intent: <B>in</B>.
<BR>
Specified as: an integer value. 
</DD>
</DL>

<P>
<DL>
<DT><STRONG><B>On Return</B></STRONG></DT>
<DD>
</DD>
<DT><STRONG>a</STRONG></DT>
<DD>the matrix to be allocated.
<BR>
Scope:<B>local</B>
<BR>
Type:<B>required</B>
<BR>
Intent: <B>out</B>.
<BR>
Specified as: a structured data of type spdata<TT>psb_spmat_type</TT>.
</DD>
<DT><STRONG>info</STRONG></DT>
<DD>Error code.
<BR>
Scope: <B>local</B> 
<BR>
Type: <B>required</B> 
<BR>
Intent: <B>out</B>.
<BR>
An integer value; 0 means no error has been detected. 
</DD>
</DL>
<FONT SIZE="+1"><B>Notes</B></FONT>

<OL>
<LI>On exit from this routine the sparse matrix  is in the build
  state.
</LI>
<LI>The descriptor may be in either the build or assembled state.
</LI>
<LI>Providing a good estimate for the number of nonzeroes <IMG
 WIDTH="32" HEIGHT="14" ALIGN="BOTTOM" BORDER="0"
 SRC="img102.png"
 ALT="$nnz$"> in
  the assembled matrix may substantially improve performance in the
  matrix build phase, as it will reduce or eliminate the need for
  (potentially multiple) data reallocations. 
</LI>
</OL>

<P>
<HR>
<!--Navigation Panel-->
<A NAME="tex2html829"
  HREF="node52.html">
<IMG WIDTH="37" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="next" SRC="next.png"></A> 
<A NAME="tex2html825"
  HREF="node44.html">
<IMG WIDTH="26" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="up" SRC="up.png"></A> 
<A NAME="tex2html819"
  HREF="node50.html">
<IMG WIDTH="63" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="previous" SRC="prev.png"></A> 
<A NAME="tex2html827"
  HREF="node1.html">
<IMG WIDTH="65" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="contents" SRC="contents.png"></A>  
<BR>
<B> Next:</B> <A NAME="tex2html830"
  HREF="node52.html">psb_spins   Insert</A>
<B> Up:</B> <A NAME="tex2html826"
  HREF="node44.html">Data management routines</A>
<B> Previous:</B> <A NAME="tex2html820"
  HREF="node50.html">psb_cdbldext   Build</A>
 &nbsp; <B>  <A NAME="tex2html828"
  HREF="node1.html">Contents</A></B> 
<!--End of Navigation Panel-->

</BODY>
</HTML>