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psblas3-type-indexed
Salvatore Filippone 19 years ago
parent aa4f68cb4c
commit 66d29c233f

@ -4,6 +4,7 @@ This directory contains the PSBLAS library, version 2.0.
Release Candidate 1: For the time being, even if the docs say that we
have both real and complex, we only have real data. When we have
complex data it will be declared RC2 or V2.0.
The users' guide is not yet completed.
The version 1.0 of the library was described in:

@ -15,8 +15,7 @@ The \hypertarget{spdata}{{\tt psb\_spmat\_type}} data structure
contains all information about local portion of the sparse matrix and
its storage mode. Many of this fields are set in fully-transparent
mode by PSBLAS-TOOLS routines when inserting a new sparse matrix, user
must set only fields which describe matrix storage mode (see
\S~\ref{psb_spall}). \\
must set only fields which describe matrix storage mode. \\
Fields contained in Sparse matrix structures are:
\begin{description}
\item[{\bf aspk}] Contains values of the local distributed sparse
@ -52,7 +51,6 @@ as in Coordinate Storage or Compressed Sparse Rows, should be greater
than or equal to the maximum column index actually present in the sparse matrix.
Specified as: integer variable.
\end{description}
Values assumed by this fields are compatible with ref. 1 (see \S~\ref{chap:appendix}).\\
FORTRAN95 interface for distributed sparse matrices containing double precision
real entries is defined as in figure~\ref{fig:spmattype}.
\begin{figure}[h!]

@ -67,9 +67,8 @@ library~\cite{scalapack}. The layered structure of the PSBLAS library
is shown in figure~\ref{fig:psblas} ; lower layers of the library
indicate an encapsulation relationship with upper layers. The ongoing
discussion focuses on the Fortran~95 layer immediately below the
application layer; two examples of iterative solvers built through the
PSBLAS routines, will be also given in Section~\ref{sec:itmethd}. The
serial parts of the computation on each process are executed through
application layer.
The serial parts of the computation on each process are executed through
calls to the serial sparse BLAS subroutines. In a similar way, the
inter-process message exchanges are implemented through the Basic
Linear Algebra Communication Subroutines (BLACS) library~\cite{BLACS}
@ -114,11 +113,11 @@ internally defined in the PSBLAS software package:
\item all the subroutine names follow the rule \verb|psb_xxname| where
\verb|xx| can be either:
\begin{itemize}
\item \verb|ds|: the routine is related to dense data,
\item \verb|ge|: the routine is related to dense data,
\item \verb|sp|: the routine is related to sparse data,
\item \verb|cd|: the routine is related to communication descriptor (see~\ref{sec:datastruct}).
\end{itemize}
For example the \verb|psb_dsins|, \verb|psb_spins| and
For example the \verb|psb_geins|, \verb|psb_spins| and
\verb|psb_cdins| perform the same action (see~\ref{sec:toolsrout}) on
dense matrices, sparse matrices and communication descriptors
respectively.

@ -3,30 +3,17 @@
% \section{Preconditioners}
\label{sec:psprecs}
Preconditioning is somehow regarded as ``black magic''. This is due to
the fact that theory doesn't provide a reliable support in the choice
of a preconditioner. It is clear that the influence of a
preconditioning technique on the convergence behavior of an iterative
method mostly depends on the characteristics of the system matrix and
of the method itself. Anyway it is not possible a priori to say that
one preconditioner is algebrically better than another and this perfectly explains
the importance of providing a wide range of preconditioners techniques
so that the user can find by itself which one is more suitable for his
problem. Moreover, there are some other issues to consider when
choosing a preconditioner such as balancing the overhead of building
the preconditioner with the reduction in the number of
iterations. PSBLAS contains the implementation of many preconditioning
PSBLAS contains the implementation of many preconditioning
techniques some of which are very flexible thanks to the presence of
many parameters that is possible to adjust to fit the user's needs:
\begin{itemize}
\item Diagonal Scaling
\item Block Jacobi with ILU(0) factorization
\item Additive Schwarz with the Restricted Additive Schwarz and
Additive Schwarz with Harmonic extensions (see
chapter~\ref{sec:pprec})
Additive Schwarz with Harmonic extensions;
\item Two-Level Additive Schwarz; this is actually a family of
preconditioners since there is the possibility to choose between
many variants as explained in chapter~\ref{sec:mlprec}
many variants.
\end{itemize}

@ -1,5 +1,5 @@
\section{Data management and initialization routines}
\label{sec:toolrout}
\label{sec:toolsrout}
%
%% psb_alloc %%
%

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