GNU Data Language

GNU Data Language (GDL) is a free/libre/open source incremental compiler compatible with IDL and to some extent with PV-WAVE and together with its library routines it serves as a tool for data analysis and visualization in such disciplines as astronomy, geosciences and medical imaging. GNU Data Language (GDL) offers features such as GDL library, supports several data formats such as netCDF, HDF4, HDF5, GRIB, PNG, TIFF, DICOM, etc. Graphical output is handled by X11, PostScript, SVG or z-buffer terminals.

The last one allowing output graphics (plots) to be saved in a variety of raster graphics formats, integrated debugging facilities and a Python bridge (Python code can be called from GDL; GDL can be compiled as a Python module). GDL as a language is dynamically-typed, vectorized and has object-oriented programming capabilities. GDL library routines handle numerical calculations, data visualization, signal/image processing, interaction with host OS and data input/output.

Graphical output is partially implemented where the PLOT, OPLOT, PLOTS, XYOUTS, CONTOUR, SURFACE, TVRD and TV commands (along with WINDOW, WDELETE, SET_PLOT, WSET, TVLCT) work (important keywords, some !P system variable tags and multi-plots are supported) for X windows, z-buffer and postscript output.

The GNU readline library 4.3 or later is needed (GDL should compile without it, but it's very inconvenient to use that way, furthermore, proper event handling for graphic windows requires readline). GDL supports compilation using both the shipped autotools "configure" script as well as using CMake. GDL was developed using ANTLR v2 but unless users want to change the grammar (*.g files) users don't need ANTLR since all relevant ANTLR files are included in the package.