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

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 numbers are the most effectual?" - Pliny the Elder.

       Karl Glazebrook [karlglazebrook@yahoo.com] and Craig DeForest  [deforest@boulder.swri.edu

DESCRIPTION

       Perl Data Language (PDL) is a perl extension that is designed for scientific 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 ordinary 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 specialized interactive shell (perldl(1)) that allows you to issue PDL
       commands interactively and that includes a path-based subroutine autoloader similar to those found in MatLab and IDL (which are trademarks
       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 complete 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 additional modules loaded, the entire CPAN archive is also
       available to your PDL scripts.

SYNOPSIS

       This manual page provides a general introduction to the underlying philosophy of PDL. For an overview over the rest of the documentation
       see PDL::Index. As a beginner the following documents are particulary recommended:

       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@yahoo.com), Tuomas J. Lukka, (lukka@husc.harvard.edu) and Christian Soeller
       (c.soeller@auckland.ac.nz) 1997-2002.

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

perl v5.12.1							    2009-10-17								  INTRO(1)