copyright and internal doc adjustments for version 1.1.
This commit is contained in:
Salvatore Filippone
2009-03-13 16:29:43 +00:00
parent 74761e16df
commit 9a1848ef3e
221 changed files with 11796 additions and 14753 deletions
+25 -25
View File
@@ -62,7 +62,7 @@ Smoothed Aggregation
<P>
In order to define the restriction operator <IMG
WIDTH="29" HEIGHT="32" ALIGN="MIDDLE" BORDER="0"
SRC="img67.png"
SRC="img68.png"
ALT="$R_C$">, which is used to compute
the coarse-level matrix <IMG
WIDTH="29" HEIGHT="32" ALIGN="MIDDLE" BORDER="0"
@@ -81,7 +81,7 @@ The basic idea of this algorithm is to build a coarse set of vertices
ALT="$W$"> into disjoint subsets
(aggregates), and to define the coarse-to-fine space transfer operator <IMG
WIDTH="29" HEIGHT="40" ALIGN="MIDDLE" BORDER="0"
SRC="img68.png"
SRC="img69.png"
ALT="$R_C^T$"> by
applying a suitable smoother to a simple piecewise constant
prolongation operator, to improve the quality of the coarse-space correction.
@@ -100,15 +100,15 @@ Three main steps can be identified in the smoothed aggregation procedure:
</LI>
<LI>construction of the prolongator <IMG
WIDTH="29" HEIGHT="40" ALIGN="MIDDLE" BORDER="0"
SRC="img68.png"
SRC="img69.png"
ALT="$R_C^T$">;
</LI>
<LI>application of <IMG
WIDTH="29" HEIGHT="32" ALIGN="MIDDLE" BORDER="0"
SRC="img67.png"
SRC="img68.png"
ALT="$R_C$"> and <IMG
WIDTH="29" HEIGHT="40" ALIGN="MIDDLE" BORDER="0"
SRC="img68.png"
SRC="img69.png"
ALT="$R_C^T$"> to build <IMG
WIDTH="29" HEIGHT="32" ALIGN="MIDDLE" BORDER="0"
SRC="img43.png"
@@ -124,14 +124,14 @@ in [<A
this algorithm has been actually considered,
in which each aggregate <IMG
WIDTH="26" HEIGHT="32" ALIGN="MIDDLE" BORDER="0"
SRC="img69.png"
SRC="img70.png"
ALT="$N_r$"> is made of vertices of <IMG
WIDTH="24" HEIGHT="15" ALIGN="BOTTOM" BORDER="0"
SRC="img10.png"
ALT="$W$"> that are <I>strongly coupled</I>
to a certain root vertex <IMG
WIDTH="53" HEIGHT="32" ALIGN="MIDDLE" BORDER="0"
SRC="img70.png"
SRC="img71.png"
ALT="$r \in W$">, i.e. <BR><P></P>
<DIV ALIGN="CENTER">
<!-- MATH
@@ -143,7 +143,7 @@ N_r = \left\{s \in W: |a_{rs}| > \theta \sqrt{|a_{rr}a_{ss}|} \right\}
<IMG
WIDTH="319" HEIGHT="38" BORDER="0"
SRC="img71.png"
SRC="img72.png"
ALT="\begin{displaymath}N_r = \left\{s \in W: \vert a_{rs}\vert &gt; \theta \sqrt{\vert a_{rr}a_{ss}\vert} \right\}
\cup \left\{ r \right\} ,
\end{displaymath}">
@@ -155,16 +155,16 @@ for a given <!-- MATH
-->
<IMG
WIDTH="69" HEIGHT="36" ALIGN="MIDDLE" BORDER="0"
SRC="img72.png"
SRC="img73.png"
ALT="$\theta \in [0,1]$">.
Since this algorithm has a sequential nature, a <I>decoupled</I> version of
it has been chosen, where each processor <IMG
WIDTH="10" HEIGHT="18" ALIGN="BOTTOM" BORDER="0"
SRC="img73.png"
WIDTH="11" HEIGHT="18" ALIGN="BOTTOM" BORDER="0"
SRC="img74.png"
ALT="$i$"> independently applies the algorithm to
the set of vertices <IMG
WIDTH="31" HEIGHT="39" ALIGN="MIDDLE" BORDER="0"
SRC="img74.png"
SRC="img75.png"
ALT="$W_i^0$"> assigned to it in the initial data distribution. This
version is embarrassingly parallel, since it does not require any data communication.
On the other hand, it may produce non-uniform aggregates near boundary vertices,
@@ -183,14 +183,14 @@ since it has been shown to produce good results in practice
<P>
The prolongator <IMG
WIDTH="75" HEIGHT="40" ALIGN="MIDDLE" BORDER="0"
SRC="img75.png"
SRC="img76.png"
ALT="$P_C=R_C^T$"> is built starting from a <I>tentative prolongator</I>
<!-- MATH
$P \in \Re^{n \times n_C}$
-->
<IMG
WIDTH="90" HEIGHT="38" ALIGN="MIDDLE" BORDER="0"
SRC="img76.png"
WIDTH="89" HEIGHT="38" ALIGN="MIDDLE" BORDER="0"
SRC="img77.png"
ALT="$P \in \Re^{n \times n_C}$">, defined as
<BR>
<DIV ALIGN="RIGHT">
@@ -207,7 +207,7 @@ P=(p_{ij}), \quad p_{ij}=
<TABLE WIDTH="100%" ALIGN="CENTER">
<TR VALIGN="MIDDLE"><TD ALIGN="CENTER" NOWRAP><A NAME="eq:tent_prol"></A><IMG
WIDTH="290" HEIGHT="52" BORDER="0"
SRC="img77.png"
SRC="img78.png"
ALT="\begin{displaymath}
P=(p_{ij}), \quad p_{ij}=
\left\{ \begin{array}{ll}
@@ -222,17 +222,17 @@ P=(p_{ij}), \quad p_{ij}=
<BR CLEAR="ALL"></DIV><P></P>
<IMG
WIDTH="27" HEIGHT="32" ALIGN="MIDDLE" BORDER="0"
SRC="img78.png"
SRC="img79.png"
ALT="$P_C$"> is obtained by
applying to <IMG
WIDTH="18" HEIGHT="15" ALIGN="BOTTOM" BORDER="0"
SRC="img79.png"
SRC="img80.png"
ALT="$P$"> a smoother <!-- MATH
$S \in \Re^{n \times n}$
-->
<IMG
WIDTH="78" HEIGHT="38" ALIGN="MIDDLE" BORDER="0"
SRC="img80.png"
SRC="img81.png"
ALT="$S \in \Re^{n \times n}$">:
<BR>
<DIV ALIGN="RIGHT">
@@ -245,7 +245,7 @@ P_C = S P,
<TABLE WIDTH="100%" ALIGN="CENTER">
<TR VALIGN="MIDDLE"><TD ALIGN="CENTER" NOWRAP><A NAME="eq:smoothed_prol"></A><IMG
WIDTH="73" HEIGHT="30" BORDER="0"
SRC="img81.png"
SRC="img82.png"
ALT="\begin{displaymath}
P_C = S P,
\end{displaymath}"></TD>
@@ -260,7 +260,7 @@ Schwarz method [<A
HREF="node25.html#StubenGMD69_99">22</A>].
A simple choice for <IMG
WIDTH="16" HEIGHT="15" ALIGN="BOTTOM" BORDER="0"
SRC="img82.png"
SRC="img83.png"
ALT="$S$"> is the damped Jacobi smoother:
<BR>
<DIV ALIGN="RIGHT">
@@ -273,7 +273,7 @@ S = I - \omega D^{-1} A ,
<TABLE WIDTH="100%" ALIGN="CENTER">
<TR VALIGN="MIDDLE"><TD ALIGN="CENTER" NOWRAP><A NAME="eq:jac_smoother"></A><IMG
WIDTH="126" HEIGHT="30" BORDER="0"
SRC="img83.png"
SRC="img84.png"
ALT="\begin{displaymath}
S = I - \omega D^{-1} A ,
\end{displaymath}"></TD>
@@ -283,11 +283,11 @@ S = I - \omega D^{-1} A ,
<BR CLEAR="ALL"></DIV><P></P>
where the value of <IMG
WIDTH="16" HEIGHT="14" ALIGN="BOTTOM" BORDER="0"
SRC="img84.png"
SRC="img85.png"
ALT="$\omega$"> can be chosen
using some estimate of the spectral radius of <IMG
WIDTH="50" HEIGHT="21" ALIGN="BOTTOM" BORDER="0"
SRC="img85.png"
WIDTH="51" HEIGHT="21" ALIGN="BOTTOM" BORDER="0"
SRC="img86.png"
ALT="$D^{-1}A$"> [<A
HREF="node25.html#BREZINA_VANEK">1</A>].