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<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_Tspmat_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="13" ALIGN="BOTTOM" BORDER="0"
 SRC="img97.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>

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