We often wish to combine observations from different spectral regions to understand the structure and physics of various objects, and a big step in frequency often means a software change. To do arithmetic with maps from different ends of the spectrum or to avoid creating macros for the same plot in several different languages, data format conversion is necessary. Most of these problems can be solved by converting the data to FITS format, but this is cumbersome and may take a lot of disk space. Direct interfaces would be more practical.
Two interfaces to the GILDAS ``.gdf'' format have now been created for ESO MIDAS ``.bdf'' image files (optical and near IR observations) and IDL (Interactive Data Language, a commercial multi purpose package, which some reduction programs use). MIDAS has been available at IRAM for several years, IDL was tested at the institute at the end of last year and will be coming soon.
The first of the interfaces is GREMLIN, which is the GREg Midas LINk. It is possible to read and write MIDAS image and descriptor data with it. GREMLIN uses the SIC command monitor and ``hijacks'' as many SIC based languages as possible, i.e. GRAPHIC, GREG, GTVL, VECTOR and TASK on Unix. The only limitation is due to conflicts if too many link-libraries are combined (attempts to capture CLIC, CLASS and ASTRO failed). A VMS version of GREMLIN is in preparation. Some commands working on SIC variables have been included, for example a multi-purpose fit algorithm (which will be included into SIC in the near future), a copy command to save the content of a variable into another, a hard delete command and a lot more. See the table below for details.
Table: List of commands available in GREMLIN.
For IDL, a routine named ``gildas.pro'' has been written that can read ``.gdf'' files (with the header). An output option is in preparation but hasn't been tested yet. Interfaces for MIDAS file input/output exist already for IDL (by Stephen A. Voels, USM/DAN) that allow to read and update image and table data. The syntax for their use will be displayed when they are called without argument:
For questions and problems concerning GREMLIN and gildas.pro, please contact Michael Bremer (firstname.lastname@example.org).