pdl

INTRO(1p)             User Contributed Perl Documentation            INTRO(1p)



NAME
       PDL::Intro - Introduction to the Perl Data Language

       Version 2.4

       "Why is it that we entertain the belief that for every purpose odd num-
       bers are the most effectual?" - Pliny the Elder.

       Karl Glazebrook [karlglazebrook AT yahoo.com] and Craig DeForest  [defor-
       est AT boulder.edu

DESCRIPTION
       Perl Data Language (PDL) is a perl extension that is designed for sci-
       entific and bulk numeric data processing and display.  It extends
       perl's syntax and includes fully vectorized, multidimensional array
       handling, plus several paths for device-independent graphics output.

       "pdl" is an interactive command shell that is supplied with PDL; for
       more information, see perldl(1).

       Because PDL is a modular extension to perl, it is accessible to ordi-
       nary perl scripts: to write a command-line PDL script you just say "use
       PDL;" at the top of an ordinary perl script.  There is also a special-
       ized interactive shell (perldl(1)) that allows you to issue PDL com-
       mands interactively and that includes a path-based subroutine
       autoloader similar to those found in MatLab and IDL (which are trade-
       marks of MathWorks and Kodak, respectively).  The perldl shell allows
       you to quickly manipulate and "play with" your data.  (You can also
       invoke it with the shorter command "pdl").

       The "PDL" module is a complete Object-Oriented extension to Perl
       (although you don't have to know what an object is to use it) which
       allows large N-dimensional data sets, such as large images, spectra,
       time series, etc to be stored efficiently and manipulated en masse.
       For example with the PDL module we can write the perl code "$a=$b+$c",
       where $b and $c are large datasets (e.g. 2048x2048 images), and get the
       result in only a fraction of a second.

       PDL variables (or piddles as they have come to be known) support a wide
       range of fundamental data types - arrays can be bytes, short integers
       (signed or unsigned), long integers, floats or double precision floats.
       And because of the Object-Oriented nature of PDL new customised
       datatypes can be derived from them.

       Perl is an extremely good and versatile scripting language, well suited
       to beginners, and allows rapid prototyping.  The PDL extensions to the
       language use Perl's object-oriented capabilities to seamlessly add
       high-speed scientific capabilities that are themselves written in perl,
       C and/or FORTRAN as appropriate -- so your code's "hot spots" run at
       native compiled-language speed, while you work in the higher level perl
       language (which itself runs faster than many other JIT-compiled or
       interpreted languages).

       External modules that have been incorporated into PDL include the com-
       plete Gnu Scientific Library; CFITSIO for FITS file handling; FFTW; the
       Slatec matrix-handling package; and the PGPLOT, PLPLOT, Karma, and
       OpenGL graphics libraries.  Ancillary packages written in PDL itself
       include image handling, curve fitting, matrix manipulation, coordinate
       transformation, nonlinear data resampling, graphics I/O, and extensive
       file I/O utilities.  Because PDL programs are "just" perl with addi-
       tional modules loaded, the entire CPAN archive is also available to
       your PDL scripts.

SYNOPSIS
       This manual page provides a general introduction to the underlying phi-
       losophy of PDL. For an overview over the rest of the documentation see
       PDL::Index. As a beginner the following documents are particulary rec-
       ommended:

       PDL::Impatient
           Quick summary - PDL for the impatient

       PDL::FAQ
           The Frequently Asked Questions list for PDL.

       PDL::Philosophy
           Why another matrix language?

       PDL::Indexing
           An introduction to using smart indices in PDL.

       PDL::NiceSlice
           The all important slicing of piddles.

AUTHOR
       Copyright (C) Karl Glazebrook (karlglazebrook AT yahoo.com), Tuomas J.
       Lukka, (lukka AT husc.edu) and Christian Soeller (c.soeller@auck-
       land.ac.nz) 1997-2002.

       Commercial reproduction of this documentation in a different format is
       forbidden without permission.



perl v5.8.8                       2003-05-21                         INTRO(1p)