Context Levels

Besides the fixed (general) MIDAS commands, the user may dynamically create new commands any time during a MIDAS session. Context files provide a way to group commands which relate to a specific reduction sequence or application package.

For example, the command SET/CONTEXT applic1 will execute the MIDAS procedure applic1.ctx, which would contain all the new command definitions for the application package applic1 as well as any new keyword definitions and default settings.
Each enabled context has a corresponding context no. which links new commands to the context in which they were created. The command SHOW/COMMANDS displays all additional MIDAS commands together with their context no. The context no. 0 is used for all commands which are created outside a given context.

Once the user has finished his/her data reduction with applic1, he/she may want to work with package applic2 on some of his/her data as well. One could either add all commands of applic2 on top of the ones from applic1 or first remove all the commands from the currently enabled context, i.e. applic1, in one go via the command CLEAR/CONTEXT.
SET/CONTEXT applic2 will then create all the new commands of the package applic2.

Use SHOW/CONTEXTS to display all the currently enabled contexts.
Up to 8 different contexts may be enabled at any time (assuming that all enabled commands fit in the MIDAS command table).
Some of the currently available contexts (application packages) are:

Astrometric Package
ccd - Reduction of CCD data
cloud - Model for absorption lines
daophot - Object detection and classification, the DAOPHOT-2 package
do - Data organizer for astronomical observations
echelle - Reduction of echelle spectra
exsas (*) - Analysis of X-ray data from the ROSAT satellite
geotest - Utilities to create geometric test frames and other artificial images
imres - Programs related to image restoration
invent - Object detection and classification, the INVENTORY package
irac2 - Reduction programs for the IRAC2 camera
irspec - Reduction of IRSPEC spectra
iue (*) - IUE-tape reader
long - Reduction of long slit spectra
lyman - Package for multiple-components fitting of interstellar absorption lines
mva - Package for multivariate data analysis
optopus - Package to prepare observations with the Optopus facility at La Silla
pepsys - Photometric planning and reductions (extinction correction + transformation to std. system)
pisco - Reduction package for data obtained with the PISCO instrument at La Silla
romafot - Photometric extraction package, the ROMAFOT software
spec - Package for 1-dim spectra
statist - Statistical tests on tables
surfphot - Deconvolution and rebinning
tsa - Package for analysis of astronomical time series
wavelet - Image processing tools using the wavelet transform

For example, the command SET/CONTEXT invent will activate the commands related to the INVENTORY photometric package.
HELP [CONTEXT] will display all currently available contexts at your site.

Note contexts exsas and iue have been developed at the Max Planck Institute for Extraterrestrial Physics in Garching, Germany and ESA Vilspa, Villafranca Satellite Tracking Station, Spain, respectively. They may be obtained on request from these institutions.