mld2p4:

configure.ac
 configure
 docs/html
 docs/html/WARNINGS
 docs/html/images.aux
 docs/html/images.log
 docs/html/images.out
 docs/html/images.pl
 docs/html/images.tex
 docs/html/img1.png
 docs/html/img10.png
 docs/html/img100.png
 docs/html/img11.png
 docs/html/img12.png
 docs/html/img13.png
 docs/html/img14.png
 docs/html/img15.png
 docs/html/img16.png
 docs/html/img17.png
 docs/html/img18.png
 docs/html/img19.png
 docs/html/img2.png
 docs/html/img20.png
 docs/html/img21.png
 docs/html/img22.png
 docs/html/img23.png
 docs/html/img24.png
 docs/html/img25.png
 docs/html/img26.png
 docs/html/img27.png
 docs/html/img28.png
 docs/html/img29.png
 docs/html/img3.png
 docs/html/img30.png
 docs/html/img31.png
 docs/html/img32.png
 docs/html/img33.png
 docs/html/img34.png
 docs/html/img35.png
 docs/html/img36.png
 docs/html/img37.png
 docs/html/img38.png
 docs/html/img39.png
 docs/html/img4.png
 docs/html/img40.png
 docs/html/img41.png
 docs/html/img42.png
 docs/html/img43.png
 docs/html/img44.png
 docs/html/img45.png
 docs/html/img46.png
 docs/html/img47.png
 docs/html/img48.png
 docs/html/img49.png
 docs/html/img5.png
 docs/html/img50.png
 docs/html/img51.png
 docs/html/img52.png
 docs/html/img53.png
 docs/html/img54.png
 docs/html/img55.png
 docs/html/img56.png
 docs/html/img57.png
 docs/html/img58.png
 docs/html/img59.png
 docs/html/img6.png
 docs/html/img60.png
 docs/html/img61.png
 docs/html/img62.png
 docs/html/img63.png
 docs/html/img64.png
 docs/html/img65.png
 docs/html/img66.png
 docs/html/img67.png
 docs/html/img68.png
 docs/html/img69.png
 docs/html/img7.png
 docs/html/img70.png
 docs/html/img71.png
 docs/html/img72.png
 docs/html/img73.png
 docs/html/img74.png
 docs/html/img75.png
 docs/html/img76.png
 docs/html/img77.png
 docs/html/img78.png
 docs/html/img79.png
 docs/html/img8.png
 docs/html/img80.png
 docs/html/img81.png
 docs/html/img82.png
 docs/html/img83.png
 docs/html/img84.png
 docs/html/img85.png
 docs/html/img86.png
 docs/html/img87.png
 docs/html/img88.png
 docs/html/img89.png
 docs/html/img9.png
 docs/html/img90.png
 docs/html/img91.png
 docs/html/img92.png
 docs/html/img93.png
 docs/html/img94.png
 docs/html/img95.png
 docs/html/img96.png
 docs/html/img97.png
 docs/html/img98.png
 docs/html/img99.png
 docs/html/index.html
 docs/html/internals.pl
 docs/html/labels.pl
 docs/html/node1.html
 docs/html/node10.html
 docs/html/node11.html
 docs/html/node12.html
 docs/html/node13.html
 docs/html/node14.html
 docs/html/node15.html
 docs/html/node16.html
 docs/html/node17.html
 docs/html/node18.html
 docs/html/node19.html
 docs/html/node2.html
 docs/html/node20.html
 docs/html/node21.html
 docs/html/node22.html
 docs/html/node23.html
 docs/html/node24.html
 docs/html/node25.html
 docs/html/node26.html
 docs/html/node27.html
 docs/html/node28.html
 docs/html/node29.html
 docs/html/node3.html
 docs/html/node30.html
 docs/html/node31.html
 docs/html/node4.html
 docs/html/node5.html
 docs/html/node6.html
 docs/html/node7.html
 docs/html/node8.html
 docs/html/node9.html
 docs/html/userhtml.css
 docs/html/userhtml.html
 docs/pdf/building.tex
 docs/userguide.pdf
 examples/fileread/mld_cexample_1lev.f90
 examples/fileread/mld_cexample_ml.f90
 examples/fileread/mld_dexample_1lev.f90
 examples/fileread/mld_dexample_ml.f90
 examples/fileread/mld_sexample_1lev.f90
 examples/fileread/mld_sexample_ml.f90
 examples/fileread/mld_zexample_1lev.f90
 examples/fileread/mld_zexample_ml.f90
 mlprec/mld_cprecset.f90
 mlprec/mld_dprecset.f90
 mlprec/mld_sprecset.f90
 mlprec/mld_zprecset.f90
 test/fileread/cf_sample.f90
 test/fileread/df_sample.f90
 test/fileread/runs/cfs.inp
 test/fileread/runs/dfs.inp
 test/fileread/runs/sfs.inp
 test/fileread/runs/zfs.inp
 test/fileread/sf_sample.f90
 test/fileread/zf_sample.f90

Fixed I/O for fileread samples.
Fixed precset typo.
Updated documentation for building.
Included HTML pages.

docs/html/node10.html

@@ -0,0 +1,190 @@
+<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN">
+
+<!--Converted with LaTeX2HTML 2002-2-1 (1.71)
+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>Multi-level Domain Decomposition Background</TITLE>
+<META NAME="description" CONTENT="Multi-level Domain Decomposition Background">
+<META NAME="keywords" CONTENT="userhtml">
+<META NAME="resource-type" CONTENT="document">
+<META NAME="distribution" CONTENT="global">
+
+<META NAME="Generator" CONTENT="LaTeX2HTML v2002-2-1">
+<META HTTP-EQUIV="Content-Style-Type" CONTENT="text/css">
+
+<LINK REL="STYLESHEET" HREF="userhtml.css">
+
+<LINK REL="next" HREF="node13.html">
+<LINK REL="previous" HREF="node5.html">
+<LINK REL="up" HREF="userhtml.html">
+<LINK REL="next" HREF="node11.html">
+</HEAD>
+
+<BODY >
+<!--Navigation Panel-->
+<A NAME="tex2html187"
+  HREF="node11.html">
+<IMG WIDTH="37" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="next"
+ SRC="file:/usr/share/latex2html/icons/next.png"></A> 
+<A NAME="tex2html183"
+  HREF="userhtml.html">
+<IMG WIDTH="26" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="up"
+ SRC="file:/usr/share/latex2html/icons/up.png"></A> 
+<A NAME="tex2html177"
+  HREF="node9.html">
+<IMG WIDTH="63" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="previous"
+ SRC="file:/usr/share/latex2html/icons/prev.png"></A> 
+<A NAME="tex2html185"
+  HREF="node1.html">
+<IMG WIDTH="65" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="contents"
+ SRC="file:/usr/share/latex2html/icons/contents.png"></A>  
+<BR>
+<B> Next:</B> <A NAME="tex2html188"
+  HREF="node11.html">Multi-level Schwarz Preconditioners</A>
+<B> Up:</B> <A NAME="tex2html184"
+  HREF="userhtml.html">userhtml</A>
+<B> Previous:</B> <A NAME="tex2html178"
+  HREF="node9.html">Example and test programs</A>
+ &nbsp; <B>  <A NAME="tex2html186"
+  HREF="node1.html">Contents</A></B> 
+<BR>
+<BR>
+<!--End of Navigation Panel-->
+
+<H1><A NAME="SECTION00060000000000000000"></A><A NAME="sec:background"></A>
+<BR>
+Multi-level Domain Decomposition Background
+</H1>
+
+<P>
+<I>Domain Decomposition</I> (DD) preconditioners, coupled with Krylov iterative
+solvers, are widely used in the parallel solution of large and sparse linear systems.
+These preconditioners are based on the divide and conquer technique: the matrix
+to be preconditioned is divided into submatrices, a ``local'' linear system
+involving each submatrix is (approximately) solved, and the local solutions are used
+to build a preconditioner for the whole original matrix. This process
+often corresponds to dividing a physical domain associated to the original matrix
+into subdomains, e.g. in a PDE discretization, to (approximately) solving the
+subproblems corresponding to the subdomains and to building an approximate
+solution of the original problem from the local solutions 
+[<A
+ HREF="node30.html#Cai_Widlund_92">6</A>,<A
+ HREF="node30.html#dd1_94">7</A>,<A
+ HREF="node30.html#dd2_96">15</A>]. 
+
+<P>
+<I>Additive Schwarz</I> preconditioners are DD preconditioners using overlapping
+submatrices, i.e. with some common rows, to couple the local information
+related to the submatrices (see, e.g., [<A
+ HREF="node30.html#dd2_96">15</A>]).
+The main motivation for choosing Additive Schwarz preconditioners is their
+intrinsic parallelism. A drawback of these
+preconditioners is that the number of iterations of the preconditioned solvers
+generally grows with the number of submatrices. This may be a serious limitation
+on parallel computers, since the number of submatrices usually matches the number
+of available processors. Optimal convergence rates, i.e. iteration numbers
+independent of the number of submatrices, can be obtained by correcting the
+preconditioner through a suitable approximation of the original linear system
+in a coarse space, which globally couples the information related to the single
+submatrices. 
+
+<P>
+<I>Two-level Schwarz</I> preconditioners are obtained
+by combining basic (one-level) Schwarz preconditioners with a coarse-level
+correction. In this context, the one-level preconditioner is often
+called `smoother'. Different two-level preconditioners are obtained by varying the
+choice of the smoother and of the coarse-level correction, and the
+way they are combined [<A
+ HREF="node30.html#dd2_96">15</A>]. The same reasoning can be applied starting
+from the coarse-level system, i.e. a coarse-space correction can be built
+from this system, thus obtaining <I>multi-level</I> preconditioners.
+
+<P>
+It is worth noting that optimal preconditioners do not necessarily correspond
+to minimum execution times. Indeed, to obtain effective multi-level preconditioners
+a tradeoff between optimality of convergence and the cost of building and applying
+the coarse-space corrections must be achieved. The choice of the number of levels,
+i.e. of the coarse-space corrections, also affects the effectiveness of the
+preconditioners. One more goal is to get convergence rates as less sensitive
+as possible to variations in the matrix coefficients.
+
+<P>
+Two main approaches can be used to build coarse-space corrections. The geometric approach
+applies coarsening strategies based on the knowledge of some physical grid associated
+to the matrix and requires the user to define grid transfer operators from the fine
+to the coarse levels and vice versa. This may result difficult for complex geometries;
+furthermore, suitable one-level preconditioners may be required to get efficient
+interplay between fine and coarse levels, e.g. when matrices with highly varying coefficients
+are considered. The algebraic approach builds coarse-space corrections using only matrix
+information. It performs a fully automatic coarsening and enforces the interplay between
+the fine and coarse levels by suitably choosing the coarse space and the coarse-to-fine
+interpolation [<A
+ HREF="node30.html#StubenGMD69_99">17</A>].
+
+<P>
+MLD2P4 uses a pure algebraic approach for building the sequence of coarse matrices
+starting from the original matrix. The algebraic approach is based on the <I>smoothed 
+aggregation</I> algorithm [<A
+ HREF="node30.html#BREZINA_VANEK">1</A>,<A
+ HREF="node30.html#VANEK_MANDEL_BREZINA">19</A>]. A decoupled version
+of this algorithm is implemented, where the smoothed aggregation is applied locally
+to each submatrix [<A
+ HREF="node30.html#TUMINARO_TONG">18</A>]. In the next two subsections we provide
+a brief description of the multi-level Schwarz preconditioners and of the smoothed
+aggregation technique as implemented in MLD2P4. For further details the user
+is referred to [<A
+ HREF="node30.html#para_04">2</A>,<A
+ HREF="node30.html#aaecc_07">3</A>,<A
+ HREF="node30.html#apnum_07">4</A>,<A
+ HREF="node30.html#dd2_96">15</A>].
+
+<P>
+<BR><HR>
+<!--Table of Child-Links-->
+<A NAME="CHILD_LINKS"><STRONG>Subsections</STRONG></A>
+
+<UL>
+<LI><A NAME="tex2html189"
+  HREF="node11.html">Multi-level Schwarz Preconditioners</A>
+<LI><A NAME="tex2html190"
+  HREF="node12.html">Smoothed Aggregation</A>
+</UL>
+<!--End of Table of Child-Links-->
+<HR>
+<!--Navigation Panel-->
+<A NAME="tex2html187"
+  HREF="node11.html">
+<IMG WIDTH="37" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="next"
+ SRC="file:/usr/share/latex2html/icons/next.png"></A> 
+<A NAME="tex2html183"
+  HREF="userhtml.html">
+<IMG WIDTH="26" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="up"
+ SRC="file:/usr/share/latex2html/icons/up.png"></A> 
+<A NAME="tex2html177"
+  HREF="node9.html">
+<IMG WIDTH="63" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="previous"
+ SRC="file:/usr/share/latex2html/icons/prev.png"></A> 
+<A NAME="tex2html185"
+  HREF="node1.html">
+<IMG WIDTH="65" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="contents"
+ SRC="file:/usr/share/latex2html/icons/contents.png"></A>  
+<BR>
+<B> Next:</B> <A NAME="tex2html188"
+  HREF="node11.html">Multi-level Schwarz Preconditioners</A>
+<B> Up:</B> <A NAME="tex2html184"
+  HREF="userhtml.html">userhtml</A>
+<B> Previous:</B> <A NAME="tex2html178"
+  HREF="node9.html">Example and test programs</A>
+ &nbsp; <B>  <A NAME="tex2html186"
+  HREF="node1.html">Contents</A></B> 
+<!--End of Navigation Panel-->
+<ADDRESS>
+Salvatore Filippone
+2008-07-22
+</ADDRESS>
+</BODY>
+</HTML>