<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN"> <!--Converted with LaTeX2HTML 2012 (1.2) 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_normi -- Infinity-Norm of Vector</TITLE> <META NAME="description" CONTENT="psb_normi -- Infinity-Norm of Vector"> <META NAME="keywords" CONTENT="userhtml"> <META NAME="resource-type" CONTENT="document"> <META NAME="distribution" CONTENT="global"> <META NAME="Generator" CONTENT="LaTeX2HTML v2012"> <META HTTP-EQUIV="Content-Style-Type" CONTENT="text/css"> <LINK REL="STYLESHEET" HREF="userhtml.css"> <LINK REL="next" HREF="node56.html"> <LINK REL="previous" HREF="node54.html"> <LINK REL="up" HREF="node51.html"> <LINK REL="next" HREF="node56.html"> </HEAD> <BODY > <!--Navigation Panel--> <A NAME="tex2html930" HREF="node56.html"> <IMG WIDTH="37" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="next" SRC="next.png"></A> <A NAME="tex2html926" HREF="node51.html"> <IMG WIDTH="26" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="up" SRC="up.png"></A> <A NAME="tex2html920" HREF="node54.html"> <IMG WIDTH="63" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="previous" SRC="prev.png"></A> <A NAME="tex2html928" HREF="node1.html"> <IMG WIDTH="65" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="contents" SRC="contents.png"></A> <BR> <B> Next:</B> <A NAME="tex2html931" HREF="node56.html">psb_geamaxs Generalized</A> <B> Up:</B> <A NAME="tex2html927" HREF="node51.html">Computational routines</A> <B> Previous:</B> <A NAME="tex2html921" HREF="node54.html">psb_gedots Generalized</A> <B> <A NAME="tex2html929" HREF="node1.html">Contents</A></B> <BR> <BR> <!--End of Navigation Panel--> <H2><A NAME="SECTION00054000000000000000"> psb_normi -- Infinity-Norm of Vector</A> </H2> <P> This function computes the infinity-norm of a vector <IMG WIDTH="13" HEIGHT="14" ALIGN="BOTTOM" BORDER="0" SRC="img20.png" ALT="$x$">. <BR> If <IMG WIDTH="13" HEIGHT="14" ALIGN="BOTTOM" BORDER="0" SRC="img20.png" ALT="$x$"> is a real vector it computes infinity norm as: <BR><P></P> <DIV ALIGN="CENTER"> <!-- MATH \begin{displaymath} amax \leftarrow \max_i |x_i| \end{displaymath} --> <IMG WIDTH="118" HEIGHT="36" BORDER="0" SRC="img29.png" ALT="\begin{displaymath}amax \leftarrow \max_i \vert x_i\vert\end{displaymath}"> </DIV> <BR CLEAR="ALL"> <P></P> else if <IMG WIDTH="13" HEIGHT="14" ALIGN="BOTTOM" BORDER="0" SRC="img20.png" ALT="$x$"> is a complex vector then it computes the infinity-norm as: <BR><P></P> <DIV ALIGN="CENTER"> <!-- MATH \begin{displaymath} amax \leftarrow \max_i {(|re(x_i)| + |im(x_i)|)} \end{displaymath} --> <IMG WIDTH="233" HEIGHT="36" BORDER="0" SRC="img30.png" ALT="\begin{displaymath}amax \leftarrow \max_i {(\vert re(x_i)\vert + \vert im(x_i)\vert)}\end{displaymath}"> </DIV> <BR CLEAR="ALL"> <P></P> <P> <PRE> psb_geamax(x, desc_a, info) psb_normi(x, desc_a, info) </PRE> <P> <BR><P></P> <DIV ALIGN="CENTER"><A NAME="1946"></A> <TABLE> <CAPTION><STRONG>Table 4:</STRONG> Data types</CAPTION> <TR><TD> <DIV ALIGN="CENTER"> <TABLE CELLPADDING=3 BORDER="1" ALIGN="CENTER"> <TR><TD ALIGN="LEFT"><IMG WIDTH="44" HEIGHT="14" ALIGN="BOTTOM" BORDER="0" SRC="img31.png" ALT="$amax$"></TD> <TD ALIGN="LEFT"><IMG WIDTH="13" HEIGHT="14" ALIGN="BOTTOM" BORDER="0" SRC="img20.png" ALT="$x$"></TD> <TD ALIGN="LEFT"><B>Function</B></TD> </TR> <TR><TD ALIGN="LEFT">Short Precision Real</TD> <TD ALIGN="LEFT">Short Precision Real</TD> <TD ALIGN="LEFT">psb_geamax</TD> </TR> <TR><TD ALIGN="LEFT">Long Precision Real</TD> <TD ALIGN="LEFT">Long Precision Real</TD> <TD ALIGN="LEFT">psb_geamax</TD> </TR> <TR><TD ALIGN="LEFT">Short Precision Real</TD> <TD ALIGN="LEFT">Short Precision Complex</TD> <TD ALIGN="LEFT">psb_geamax</TD> </TR> <TR><TD ALIGN="LEFT">Long Precision Real</TD> <TD ALIGN="LEFT">Long Precision Complex</TD> <TD ALIGN="LEFT">psb_geamax</TD> </TR> </TABLE> </DIV> </TD></TR> </TABLE> </DIV><P></P> <BR> <P> <DL> <DT><STRONG>Type:</STRONG></DT> <DD>Synchronous. </DD> <DT><STRONG><B>On Entry</B></STRONG></DT> <DD> </DD> <DT><STRONG>x</STRONG></DT> <DD>the local portion of global dense matrix <IMG WIDTH="13" HEIGHT="14" ALIGN="BOTTOM" BORDER="0" SRC="img20.png" ALT="$x$">. <BR> Scope: <B>local</B> <BR> Type: <B>required</B> <BR> Intent: <B>in</B>. <BR> Specified as: a rank one or two array or an object of type vdata<TT>psb_T_vect_type</TT> containing numbers of type specified in Table <A HREF="#tab:f90amax">4</A>. </DD> <DT><STRONG>desc_a</STRONG></DT> <DD>contains data structures for communications. <BR> Scope: <B>local</B> <BR> Type: <B>required</B> <BR> Intent: <B>in</B>. <BR> Specified as: an object of type descdata<TT>psb_desc_type</TT>. <P> </DD> <DT><STRONG><B>On Return</B></STRONG></DT> <DD> </DD> <DT><STRONG>Function value</STRONG></DT> <DD>is the infinity norm of subvector <IMG WIDTH="13" HEIGHT="14" ALIGN="BOTTOM" BORDER="0" SRC="img20.png" ALT="$x$">. <BR> Scope: <B>global</B> <BR> Specified as: a long precision real number. </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> <P> <HR> <!--Navigation Panel--> <A NAME="tex2html930" HREF="node56.html"> <IMG WIDTH="37" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="next" SRC="next.png"></A> <A NAME="tex2html926" HREF="node51.html"> <IMG WIDTH="26" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="up" SRC="up.png"></A> <A NAME="tex2html920" HREF="node54.html"> <IMG WIDTH="63" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="previous" SRC="prev.png"></A> <A NAME="tex2html928" HREF="node1.html"> <IMG WIDTH="65" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="contents" SRC="contents.png"></A> <BR> <B> Next:</B> <A NAME="tex2html931" HREF="node56.html">psb_geamaxs Generalized</A> <B> Up:</B> <A NAME="tex2html927" HREF="node51.html">Computational routines</A> <B> Previous:</B> <A NAME="tex2html921" HREF="node54.html">psb_gedots Generalized</A> <B> <A NAME="tex2html929" HREF="node1.html">Contents</A></B> <!--End of Navigation Panel--> </BODY> </HTML>