<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<!-- Converted with LaTeX2HTML 2018 (Released Feb 1, 2018) -->
< HTML >
< HEAD >
< TITLE > Method apply< / TITLE >
< META NAME = "description" CONTENT = "Method apply" >
< META NAME = "keywords" CONTENT = "userhtml" >
< META NAME = "resource-type" CONTENT = "document" >
< META NAME = "distribution" CONTENT = "global" >
< META NAME = "Generator" CONTENT = "LaTeX2HTML v2018" >
< META HTTP-EQUIV = "Content-Style-Type" CONTENT = "text/css" >
< LINK REL = "STYLESHEET" HREF = "userhtml.css" >
< LINK REL = "next" HREF = "node25.html" >
< LINK REL = "previous" HREF = "node23.html" >
< LINK REL = "up" HREF = "node18.html" >
< LINK REL = "next" HREF = "node25.html" >
< / HEAD >
< BODY >
< DIV CLASS = "navigation" > <!-- Navigation Panel -->
< A NAME = "tex2html392"
HREF="node25.html">
< IMG WIDTH = "37" HEIGHT = "24" ALIGN = "BOTTOM" BORDER = "0" ALT = "next" SRC = "next.png" > < / A >
< A NAME = "tex2html388"
HREF="node18.html">
< IMG WIDTH = "26" HEIGHT = "24" ALIGN = "BOTTOM" BORDER = "0" ALT = "up" SRC = "up.png" > < / A >
< A NAME = "tex2html382"
HREF="node23.html">
< IMG WIDTH = "63" HEIGHT = "24" ALIGN = "BOTTOM" BORDER = "0" ALT = "previous" SRC = "prev.png" > < / A >
< A NAME = "tex2html390"
HREF="node2.html">
< IMG WIDTH = "65" HEIGHT = "24" ALIGN = "BOTTOM" BORDER = "0" ALT = "contents" SRC = "contents.png" > < / A >
< BR >
< B > Next:< / B > < A NAME = "tex2html393"
HREF="node25.html">Method free< / A >
< B > Up:< / B > < A NAME = "tex2html389"
HREF="node18.html">User Interface< / A >
< B > Previous:< / B > < A NAME = "tex2html383"
HREF="node23.html">Method build< / A >
< B > < A NAME = "tex2html391"
HREF="node2.html">Contents< / A > < / B >
< BR >
< BR > < / DIV >
<!-- End of Navigation Panel -->
< H2 > < A NAME = "SECTION00086000000000000000" > < / A > < A NAME = "sec:precapply" > < / A >
< BR >
Method apply
< / H2 > < BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" > < / BIG > < / BIG >
< P >
< BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" > < / BIG > < / BIG >
< DIV ALIGN = "CENTER" > < BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" > < code > call p%apply(x,y,desc_a,info [,trans,work])< / code >
< BR > < / BIG > < / BIG > < / BIG > < / DIV > < BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" > < / BIG > < / BIG >
< P >
< BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" >
This method computes <!-- MATH
$y = op(B^{-1})\, x$
-->
< SPAN CLASS = "MATH" > < IMG
WIDTH="112" HEIGHT="37" ALIGN="MIDDLE" BORDER="0"
SRC="img86.png"
ALT="$y = op(B^{-1}) x$">< / SPAN > , where < SPAN CLASS = "MATH" > < IMG
WIDTH="19" HEIGHT="15" ALIGN="BOTTOM" BORDER="0"
SRC="img24.png"
ALT="$B$">< / SPAN > is a previously built
preconditioner, stored into < code > p< / code > , and < SPAN CLASS = "MATH" > < IMG
WIDTH="21" HEIGHT="31" ALIGN="MIDDLE" BORDER="0"
SRC="img87.png"
ALT="$op$">< / SPAN >
denotes the preconditioner itself or its transpose, according to
the value of < code > trans< / code > .
Note that, when MLD2P4 is used with a Krylov solver from PSBLAS,
< code > p%apply< / code > is called within the PSBLAS method < code > psb_krylov< / code >
and hence it is completely transparent to the user.
< / BIG > < / BIG > < / BIG >
< P >
< BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" > < B > Arguments< / B > < / BIG > < / BIG > < / BIG > < / BIG >
< P > < / P >
< BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" > < / BIG > < / BIG >
< P >
< BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" > < / BIG > < / BIG > < TABLE CELLPADDING = 3 >
< TR > < TD ALIGN = "LEFT" VALIGN = "TOP" WIDTH = 34 > < BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" >
< code > x< / code > < / BIG > < / BIG > < / BIG > < / TD >
< TD ALIGN = "LEFT" VALIGN = "TOP" WIDTH = 340 > < BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" > < SPAN CLASS = "textit" > type< / SPAN > < code > (< / code > < SPAN CLASS = "textit" > kind_parameter< / SPAN > < code > ), dimension(:), intent(in)< / code > .< / BIG > < / BIG > < / BIG > < / TD >
< / TR >
< TR > < TD ALIGN = "LEFT" VALIGN = "TOP" WIDTH = 34 > < BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" >
< / BIG > < / BIG > < / BIG > < / TD >
< TD ALIGN = "LEFT" VALIGN = "TOP" WIDTH = 340 > < BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" > The local part of the vector < SPAN CLASS = "MATH" > < IMG
WIDTH="15" HEIGHT="18" ALIGN="BOTTOM" BORDER="0"
SRC="img88.png"
ALT="$x$">< / SPAN > . Note that < SPAN CLASS = "textit" > type< / SPAN > and
< SPAN CLASS = "textit" > kind_parameter< / SPAN > must be chosen according
to the real/complex, single/double precision version of MLD2P4 under use.< / BIG > < / BIG > < / BIG > < / TD >
< / TR >
< TR > < TD ALIGN = "LEFT" VALIGN = "TOP" WIDTH = 34 > < BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" >
< code > y< / code > < / BIG > < / BIG > < / BIG > < / TD >
< TD ALIGN = "LEFT" VALIGN = "TOP" WIDTH = 340 > < BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" > < SPAN CLASS = "textit" > type< / SPAN > < code > (< / code > < SPAN CLASS = "textit" > kind_parameter< / SPAN > < code > ), dimension(:), intent(out)< / code > .< / BIG > < / BIG > < / BIG > < / TD >
< / TR >
< TR > < TD ALIGN = "LEFT" VALIGN = "TOP" WIDTH = 34 > < BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" >
< / BIG > < / BIG > < / BIG > < / TD >
< TD ALIGN = "LEFT" VALIGN = "TOP" WIDTH = 340 > < BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" > The local part of the vector < SPAN CLASS = "MATH" > < IMG
WIDTH="13" HEIGHT="31" ALIGN="MIDDLE" BORDER="0"
SRC="img89.png"
ALT="$y$">< / SPAN > . Note that < SPAN CLASS = "textit" > type< / SPAN > and
< SPAN CLASS = "textit" > kind_parameter< / SPAN > must be chosen according
to the real/complex, single/double precision version of MLD2P4 under use.< / BIG > < / BIG > < / BIG > < / TD >
< / TR >
< TR > < TD ALIGN = "LEFT" VALIGN = "TOP" WIDTH = 34 > < BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" >
< code > desc_a< / code > < / BIG > < / BIG > < / BIG > < / TD >
< TD ALIGN = "LEFT" VALIGN = "TOP" WIDTH = 340 > < BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" > < code > type(psb_desc_type), intent(in)< / code > . < / BIG > < / BIG > < / BIG > < / TD >
< / TR >
< TR > < TD ALIGN = "LEFT" VALIGN = "TOP" WIDTH = 34 > < BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" >
< / BIG > < / BIG > < / BIG > < / TD >
< TD ALIGN = "LEFT" VALIGN = "TOP" WIDTH = 340 > < BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" > The communication descriptor associated to the matrix to be
preconditioned.< / BIG > < / BIG > < / BIG > < / TD >
< / TR >
< TR > < TD ALIGN = "LEFT" VALIGN = "TOP" WIDTH = 34 > < BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" >
< code > info< / code > < / BIG > < / BIG > < / BIG > < / TD >
< TD ALIGN = "LEFT" VALIGN = "TOP" WIDTH = 340 > < BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" > < code > integer, intent(out)< / code > .< / BIG > < / BIG > < / BIG > < / TD >
< / TR >
< TR > < TD ALIGN = "LEFT" VALIGN = "TOP" WIDTH = 34 > < BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" >
< / BIG > < / BIG > < / BIG > < / TD >
< TD ALIGN = "LEFT" VALIGN = "TOP" WIDTH = 340 > < BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" > Error code. If no error, 0 is returned. See Section < A HREF = "node34.html#sec:errors" > 8< / A > for details.< / BIG > < / BIG > < / BIG > < / TD >
< / TR >
< TR > < TD ALIGN = "LEFT" VALIGN = "TOP" WIDTH = 34 > < BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" >
< code > trans< / code > < / BIG > < / BIG > < / BIG > < / TD >
< TD ALIGN = "LEFT" VALIGN = "TOP" WIDTH = 340 > < BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" > < code > character(len=1), optional, intent(in).< / code > < / BIG > < / BIG > < / BIG > < / TD >
< / TR >
< TR > < TD ALIGN = "LEFT" VALIGN = "TOP" WIDTH = 34 > < BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" >
< / BIG > < / BIG > < / BIG > < / TD >
< TD ALIGN = "LEFT" VALIGN = "TOP" WIDTH = 340 > < BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" > If < code > trans< / code > = < code > 'N','n'< / code > then <!-- MATH
$op(B^{-1}) = B^{-1}$
-->
< SPAN CLASS = "MATH" > < IMG
WIDTH="123" HEIGHT="39" ALIGN="MIDDLE" BORDER="0"
SRC="img90.png"
ALT="$op(B^{-1}) = B^{-1}$">< / SPAN > ;
if < code > trans< / code > = < code > 'T','t'< / code > then <!-- MATH
$op(B^{-1}) = B^{-T}$
-->
< SPAN CLASS = "MATH" > < IMG
WIDTH="126" HEIGHT="40" ALIGN="MIDDLE" BORDER="0"
SRC="img91.png"
ALT="$op(B^{-1}) = B^{-T}$">< / SPAN >
(transpose of < SPAN CLASS = "MATH" > < IMG
WIDTH="44" HEIGHT="39" ALIGN="MIDDLE" BORDER="0"
SRC="img92.png"
ALT="$B^{-1})$">< / SPAN > ; if < code > trans< / code > = < code > 'C','c'< / code > then <!-- MATH
$op(B^{-1}) = B^{-C}$
-->
< SPAN CLASS = "MATH" > < IMG
WIDTH="126" HEIGHT="40" ALIGN="MIDDLE" BORDER="0"
SRC="img93.png"
ALT="$op(B^{-1}) = B^{-C}$">< / SPAN >
(conjugate transpose of < SPAN CLASS = "MATH" > < IMG
WIDTH="44" HEIGHT="39" ALIGN="MIDDLE" BORDER="0"
SRC="img92.png"
ALT="$B^{-1})$">< / SPAN > .< / BIG > < / BIG > < / BIG > < / TD >
< / TR >
< TR > < TD ALIGN = "LEFT" VALIGN = "TOP" WIDTH = 34 > < BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" >
< code > work< / code > < / BIG > < / BIG > < / BIG > < / TD >
< TD ALIGN = "LEFT" VALIGN = "TOP" WIDTH = 340 > < BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" > < SPAN CLASS = "textit" > type< / SPAN > < code > (< / code > < SPAN CLASS = "textit" > kind_parameter< / SPAN > < code > ), dimension(:), optional, target< / code > .< / BIG > < / BIG > < / BIG > < / TD >
< / TR >
< TR > < TD ALIGN = "LEFT" VALIGN = "TOP" WIDTH = 34 > < BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" >
< / BIG > < / BIG > < / BIG > < / TD >
< TD ALIGN = "LEFT" VALIGN = "TOP" WIDTH = 340 > < BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" > Workspace. Its size should be at
least < code > 4 * psb_cd_get_local_< / code > < code > cols(desc_a)< / code > (see the PSBLAS User's Guide).
Note that < SPAN CLASS = "textit" > type< / SPAN > and < SPAN CLASS = "textit" > kind_parameter< / SPAN > must be chosen according
to the real/complex, single/double precision version of MLD2P4 under use.< / BIG > < / BIG > < / BIG > < / TD >
< / TR >
< / TABLE > < BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" > < / BIG > < / BIG >
< P >
< BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" > For compatibility with the previous versions of MLD2P4, this method can be also invoked
as follows:
< / BIG > < / BIG > < / BIG >
< P >
< BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" > < / BIG > < / BIG >
< DIV ALIGN = "CENTER" > < BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" > < code > call mld_precaply(p,what,val,info)< / code >
< / BIG > < / BIG > < / BIG > < / DIV > < BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" > < / BIG > < / BIG >
< P >
< BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" > < / BIG > < / BIG >
< P >
< BIG CLASS = "LARGE" > < BIG CLASS = "LARGE" > < / BIG > < / BIG >
< DIV CLASS = "navigation" > < HR >
<!-- Navigation Panel -->
< A NAME = "tex2html392"
HREF="node25.html">
< IMG WIDTH = "37" HEIGHT = "24" ALIGN = "BOTTOM" BORDER = "0" ALT = "next" SRC = "next.png" > < / A >
< A NAME = "tex2html388"
HREF="node18.html">
< IMG WIDTH = "26" HEIGHT = "24" ALIGN = "BOTTOM" BORDER = "0" ALT = "up" SRC = "up.png" > < / A >
< A NAME = "tex2html382"
HREF="node23.html">
< IMG WIDTH = "63" HEIGHT = "24" ALIGN = "BOTTOM" BORDER = "0" ALT = "previous" SRC = "prev.png" > < / A >
< A NAME = "tex2html390"
HREF="node2.html">
< IMG WIDTH = "65" HEIGHT = "24" ALIGN = "BOTTOM" BORDER = "0" ALT = "contents" SRC = "contents.png" > < / A >
< BR >
< B > Next:< / B > < A NAME = "tex2html393"
HREF="node25.html">Method free< / A >
< B > Up:< / B > < A NAME = "tex2html389"
HREF="node18.html">User Interface< / A >
< B > Previous:< / B > < A NAME = "tex2html383"
HREF="node23.html">Method build< / A >
< B > < A NAME = "tex2html391"
HREF="node2.html">Contents< / A > < / B > < / DIV >
<!-- End of Navigation Panel -->
< / BODY >
< / HTML >
