A free IDL (Interactive Data Language) compatible incremental compiler (ie. runs IDL programs). IDL is a registered trademark of Research Systems Inc.
Full syntax compatibility with IDL 6.0
ALL IDL language elements are supported, including:
· System variables,
· Common blocks,
· Assoc variables,
· All operators,
· All datatypes,
· _EXTRA, _STRICT_EXTRA and _REF_EXTRA keywords...
The file input output system is fully implemented
(Exception: For formatted I/O the C() sub-codes are not supported yet)
netCDF files are fully supported.
HDF files are partially supported.
Basic support for HDF5 files.
Overall more than 240 library routines are implemented. For a sorted list enter HELP,/LIB at the command prompt and look for library routines written in GDL in the src/pro subdirectory.
The WRITEFITS procedure and the READFITS function from the IDL Astronomy User's Library compile and run under GDL.
Graphical output is partially implemented. The PLOT, OPLOT, PLOTS, XYOUTS 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 and postscript output.
GDL has an interface to python.
No GUI support (widgets) is implemented so far.
GDL is free software licensed under the GPL
What's New in This Release:
· This version is much faster.
· The actual increase in speed depends upon several factors like program structure, called routines, processor, and compiler used, but up to 60% seems to not be unrealistic.
· Some new important subroutines were implemented, including CREATE_STRUCT, CONTOUR, LAGUERRE, and STRCMP. SYSTIME now has sub-millisecond resolution.
· For the FFT procedure, the FFTW library can (alternatively) be used, resulting in about double the execution speed.