<!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_gedot -- Dot Product</TITLE> <META NAME="description" CONTENT="psb_gedot -- Dot Product"> <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="node54.html"> <LINK REL="previous" HREF="node52.html"> <LINK REL="up" HREF="node51.html"> <LINK REL="next" HREF="node54.html"> </HEAD> <BODY > <!--Navigation Panel--> <A NAME="tex2html906" HREF="node54.html"> <IMG WIDTH="37" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="next" SRC="next.png"></A> <A NAME="tex2html902" HREF="node51.html"> <IMG WIDTH="26" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="up" SRC="up.png"></A> <A NAME="tex2html896" HREF="node52.html"> <IMG WIDTH="63" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="previous" SRC="prev.png"></A> <A NAME="tex2html904" HREF="node1.html"> <IMG WIDTH="65" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="contents" SRC="contents.png"></A> <BR> <B> Next:</B> <A NAME="tex2html907" HREF="node54.html">psb_gedots Generalized</A> <B> Up:</B> <A NAME="tex2html903" HREF="node51.html">Computational routines</A> <B> Previous:</B> <A NAME="tex2html897" HREF="node52.html">psb_geaxpby General</A> <B> <A NAME="tex2html905" HREF="node1.html">Contents</A></B> <BR> <BR> <!--End of Navigation Panel--> <H2><A NAME="SECTION00052000000000000000"> psb_gedot -- Dot Product</A> </H2> <P> This function computes dot product between two vectors <IMG WIDTH="14" HEIGHT="14" ALIGN="BOTTOM" BORDER="0" SRC="img20.png" ALT="$x$"> and <IMG WIDTH="13" HEIGHT="30" ALIGN="MIDDLE" BORDER="0" SRC="img21.png" ALT="$y$">. <BR> If <IMG WIDTH="14" HEIGHT="14" ALIGN="BOTTOM" BORDER="0" SRC="img20.png" ALT="$x$"> and <IMG WIDTH="13" HEIGHT="30" ALIGN="MIDDLE" BORDER="0" SRC="img21.png" ALT="$y$"> are real vectors it computes dot-product as: <BR><P></P> <DIV ALIGN="CENTER"> <!-- MATH \begin{displaymath} dot \leftarrow x^T y \end{displaymath} --> <IMG WIDTH="74" HEIGHT="27" BORDER="0" SRC="img24.png" ALT="\begin{displaymath}dot \leftarrow x^T y\end{displaymath}"> </DIV> <BR CLEAR="ALL"> <P></P> Else if <IMG WIDTH="14" HEIGHT="14" ALIGN="BOTTOM" BORDER="0" SRC="img20.png" ALT="$x$"> and <IMG WIDTH="13" HEIGHT="30" ALIGN="MIDDLE" BORDER="0" SRC="img21.png" ALT="$y$"> are complex vectors then it computes dot-product as: <BR><P></P> <DIV ALIGN="CENTER"> <!-- MATH \begin{displaymath} dot \leftarrow x^H y \end{displaymath} --> <IMG WIDTH="75" HEIGHT="27" BORDER="0" SRC="img25.png" ALT="\begin{displaymath}dot \leftarrow x^H y\end{displaymath}"> </DIV> <BR CLEAR="ALL"> <P></P> <P> <PRE> psb_gedot(x, y, desc_a, info) </PRE> <BR><P></P> <DIV ALIGN="CENTER"><A NAME="1944"></A> <TABLE> <CAPTION><STRONG>Table 2:</STRONG> Data types</CAPTION> <TR><TD> <DIV ALIGN="CENTER"> <TABLE CELLPADDING=3 BORDER="1" ALIGN="CENTER"> <TR><TD ALIGN="LEFT"><IMG WIDTH="25" HEIGHT="15" ALIGN="BOTTOM" BORDER="0" SRC="img26.png" ALT="$dot$">, <IMG WIDTH="14" HEIGHT="14" ALIGN="BOTTOM" BORDER="0" SRC="img20.png" ALT="$x$">, <IMG WIDTH="13" HEIGHT="30" ALIGN="MIDDLE" BORDER="0" SRC="img21.png" ALT="$y$"></TD> <TD ALIGN="LEFT"><B>Function</B></TD> </TR> <TR><TD ALIGN="LEFT">Short Precision Real</TD> <TD ALIGN="LEFT">psb_gedot</TD> </TR> <TR><TD ALIGN="LEFT">Long Precision Real</TD> <TD ALIGN="LEFT">psb_gedot</TD> </TR> <TR><TD ALIGN="LEFT">Short Precision Complex</TD> <TD ALIGN="LEFT">psb_gedot</TD> </TR> <TR><TD ALIGN="LEFT">Long Precision Complex</TD> <TD ALIGN="LEFT">psb_gedot</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="14" 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:f90dot">2</A>. The rank of <IMG WIDTH="14" HEIGHT="14" ALIGN="BOTTOM" BORDER="0" SRC="img20.png" ALT="$x$"> must be the same of <IMG WIDTH="13" HEIGHT="30" ALIGN="MIDDLE" BORDER="0" SRC="img21.png" ALT="$y$">. </DD> <DT><STRONG>y</STRONG></DT> <DD>the local portion of global dense matrix <IMG WIDTH="13" HEIGHT="30" ALIGN="MIDDLE" BORDER="0" SRC="img21.png" ALT="$y$">. <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:f90dot">2</A>. The rank of <IMG WIDTH="13" HEIGHT="30" ALIGN="MIDDLE" BORDER="0" SRC="img21.png" ALT="$y$"> must be the same of <IMG WIDTH="14" HEIGHT="14" ALIGN="BOTTOM" BORDER="0" SRC="img20.png" ALT="$x$">. </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 dot product of subvectors <IMG WIDTH="14" HEIGHT="14" ALIGN="BOTTOM" BORDER="0" SRC="img20.png" ALT="$x$"> and <IMG WIDTH="13" HEIGHT="30" ALIGN="MIDDLE" BORDER="0" SRC="img21.png" ALT="$y$">. <BR> Scope: <B>global</B> <BR> Specified as: a number of the data type indicated in Table <A HREF="#tab:f90dot">2</A>. </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="tex2html906" HREF="node54.html"> <IMG WIDTH="37" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="next" SRC="next.png"></A> <A NAME="tex2html902" HREF="node51.html"> <IMG WIDTH="26" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="up" SRC="up.png"></A> <A NAME="tex2html896" HREF="node52.html"> <IMG WIDTH="63" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="previous" SRC="prev.png"></A> <A NAME="tex2html904" HREF="node1.html"> <IMG WIDTH="65" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="contents" SRC="contents.png"></A> <BR> <B> Next:</B> <A NAME="tex2html907" HREF="node54.html">psb_gedots Generalized</A> <B> Up:</B> <A NAME="tex2html903" HREF="node51.html">Computational routines</A> <B> Previous:</B> <A NAME="tex2html897" HREF="node52.html">psb_geaxpby General</A> <B> <A NAME="tex2html905" HREF="node1.html">Contents</A></B> <!--End of Navigation Panel--> </BODY> </HTML>