The GNU Data Language is a free

Free software

Free software, software libre or libre software is software that can be used, studied, and modified without restriction, and which can be copied and redistributed in modified or unmodified form either without restriction, or with restrictions that only ensure that further recipients can also do...

, compatible alternative to IDL (Interactive Data Language).. Version 0.9.1, released in March 2011, has full syntax compatibility with IDL 7.1 and supports some IDL 8.0 language elements as well. GDL is in beta stage of development. Together with its library routines GDL is used as a tool for data analysis and visualization in such disciplines as astronomy, geosciences and medical imaging. GDL is licensed under the GPL

GNU General Public License

The GNU General Public License is the most widely used free software license, originally written by Richard Stallman for the GNU Project....

. Other open-source numerical data analysis tools similar to GDL include GNU Octave

GNU Octave

GNU Octave is a high-level language, primarily intended for numerical computations. It provides a convenient command-line interface for solving linear and nonlinear problems numerically, and for performing other numerical experiments using a language that is mostly compatible with MATLAB...

, NCL - NCAR Command Language

NCAR Command Language

The NCAR Command Language is a free interpreted language designed by the National Center for Atmospheric Research for scientific visualization and data processing. NCL has robust file input and output...

, PDL - Perl Data Language

Perl Data Language

PDL is a set of array programming extensions to the Perl programming language.PDL is an extension to Perl v5, intended for scientific and other data intensive programming tasks...

, R

R (programming language)

R is a programming language and software environment for statistical computing and graphics. The R language is widely used among statisticians for developing statistical software, and R is widely used for statistical software development and data analysis....

, Scilab

Scilab

Scilab is an open source, cross-platform numerical computational package and a high-level, numerically oriented programming language. Itcan be used for signal processing, statistical analysis, image enhancement, fluid dynamics simulations, numerical optimization, and modeling and simulation of...

, SciPy

SciPy

SciPy is an open source library of algorithms and mathematical tools for the Python programming language.SciPy contains modules for optimization, linear algebra, integration, interpolation, special functions, FFT, signal and image processing, ODE solvers and other tasks common in science and...

, Yorick.

GDL as a language is dynamically-typed, vectorized and has object-oriented programming capabilities. GDL library routines handle numerical calculations (e.g. FFT), data visualisation, signal/image processing, interaction with host OS and data input/output. GDL supports several data formats such as NetCDF

NetCDF

NetCDF is a set of software libraries and self-describing, machine-independent data formats that support the creation, access, and sharing of array-oriented scientific data. The project homepage is hosted by the Unidata program at the University Corporation for Atmospheric Research...

, HDF

Hierarchical Data Format

Hierarchical Data Format is the name of a set of file formats and libraries designed to store and organize large amounts of numerical data...

 (v4 & v5), GRIB

GRIB

GRIB is a mathematically concise data format commonly used in meteorology to store historical and forecast weather data...

, PNG, TIFF, DICOM, etc. Graphical output is handled by X11, PostScript

PostScript

PostScript is a dynamically typed concatenative programming language created by John Warnock and Charles Geschke in 1982. It is best known for its use as a page description language in the electronic and desktop publishing areas. Adobe PostScript 3 is also the worldwide printing and imaging...

, SVG or z-buffer terminals, the last one allowing output graphics (plots) to be saved in raster graphics formats. GDL features integrated debugging facilities (e.g. breakpoints

Breakpoint

In software development, a breakpoint is an intentional stopping or pausing place in a program, put in place for debugging purposes. It is also sometimes simply referred to as a pause....

). GDL has a Python

Python (programming language)

Python is a general-purpose, high-level programming language whose design philosophy emphasizes code readability. Python claims to "[combine] remarkable power with very clear syntax", and its standard library is large and comprehensive...

 bridge (Python code can be called from GDL; GDL can be compiled as a Python module).

Packaged versions of GDL are available for several Linux

Linux

Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds...

 and BSD flavours as well as Mac OS X

Mac OS X

Mac OS X is a series of Unix-based operating systems and graphical user interfaces developed, marketed, and sold by Apple Inc. Since 2002, has been included with all new Macintosh computer systems...

. The source code compiles on other UNIX

Unix

Unix is a multitasking, multi-user computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs, including Ken Thompson, Dennis Ritchie, Brian Kernighan, Douglas McIlroy, and Joe Ossanna...

 systems, including Solaris.

GDL is not an official GNU package.

External links

• Running the GNU Data Language on coLinux
• Linux packages: ArchLinux, Debian, Fedora, Gentoo, Ubuntu,
• BSD/OSX ports: Fink, FreeBSD, Macports
• A partial list of IDL 6.1 routines available in GDL as of September 2010