Keywords: map

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## A bit of history

Implementation of imaging and deconvolution algorithms inside GILDAS started in the early nighties. The first implementation was made as a collection of independent programs, called tasks in the GILDAS environment, and activated through the `RUN` command in the GRAPHIC program. The main advantage was the ease of programing, the main drawback was the lack of user-friendliness. To tackle this drawback, two different approaches were used.

- First, the calling of tasks were hidden through the call to SIC procedures (the `GO` and `INPUT` families of scripts) whose behaviors was modified by global variables. The activation of the tasks and the development of the SIC procedures happened in a preexisting program, called GRAPHIC which also contained the tools to visualize and analyze the spectra cubes.
- Second, a single, big program, called MAPPING, was developed with flexibility in mind, e.g. the possibility to interactively define supports where to search for clean components. The support for deconvolution of mosaics was built only in MAPPING. The same procedure names were used in MAPPING and GRAPHIC to obtain the same look-and-feel.

Up to 2003, there thus were two GILDAS program, i.e. MAPPING and GRAPHIC, which offered slightly different services with procedures sharing the same names. The status of the GRAPHIC program was difficult to understand as it shared similarities with the GREG program (which defines all the drawing commands of GILDAS) and with the MAPPING program. We thus decided during the 2003 change of GILDAS architecture to transfer the visualization and analysis capacities of GRAPHIC in GREG and the imaging and deconvolution capacities of GRAPHIC in MAPPING. The GRAPHIC program was deprecated and we made the GREG and MAPPING program able to understand the `graphic` extension of procedure files for backward compatibility. The major drawback of this decision is the fact that we currently have in the same program (i.e. MAPPING) both tasks, procedures and commands to do similar but slightly different things. Not much happened following this step due to manpower shortage in the GILDAS team. Our goal in the coming years is to clean this situation by ensuring that both tasks and commands use the same FORTRAN code. Our first main step is to update the documentation.

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