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<H2><A NAME="SECTION00081000000000000000">
psb_init -- Initializes PSBLAS parallel environment</A>
</H2>

<P>
<PRE>
call psb_init(icontxt, np)
</PRE>

<P>
This subroutine initializes the PSBLAS parallel environment, defining
a virtual parallel machine.
<DL>
<DT><STRONG>Type:</STRONG></DT>
<DD>Synchronous.
</DD>
<DT><STRONG><B>On Entry </B></STRONG></DT>
<DD>
</DD>
<DT><STRONG>np</STRONG></DT>
<DD>Number of processes in the PSBLAS virtual parallel machine.
<BR>
Scope: <B>global</B>.
<BR>
Type: <B>optional</B>.
<BR>
Intent: <B>in</B>.
<BR>
Specified as: an integer value.  Default: use all available processes provided by the underlying
parallel environment.
</DD>
</DL>

<P>
<DL>
<DT><STRONG><B>On Return</B></STRONG></DT>
<DD>
</DD>
<DT><STRONG>icontxt</STRONG></DT>
<DD>the communication context identifying the virtual
  parallel machine.
<BR>
Scope: <B>global</B>.
<BR>
Type: <B>required</B>.
<BR>
Intent: <B>out</B>.
<BR>
Specified as: an integer variable.
</DD>
</DL>

<P>
<FONT SIZE="+1"><B>Notes</B></FONT>

<OL>
<LI>A call to this routine must precede any other PSBLAS call. 
</LI>
<LI>It is an error to specify a value for <IMG
 WIDTH="22" HEIGHT="30" ALIGN="MIDDLE" BORDER="0"
 SRC="img121.png"
 ALT="$np$"> greater than the
  number of processes available in the underlying parallel execution
  environment. 
</LI>
</OL>

<P>
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