% @(#)contex.alq	19.1 (ESO-IPG) 02/25/03 14:03:05 

    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 that 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 that 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 "applic1" in one go
    via the command `CLEAR/CONTEXT applic1'.

    `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 20 different contexts may be enabled together at a given time.
    Also, note that the context names cannot be longer than 8 characters.


    Currently, the following contexts are available from ESO:


    CONTEXT      DESCRIPTION
    ---------    ----------------------------------------------------
    cloud        Model for absorption lines 
    daophot      Object detection and classification, the DAOPHOT-2 package
    echelle      Reduction of echelle spectra
    geotest      Utilities to create geometric test frames and other
                 artifical images
    imres        Programs related to image restoration 
    invent       Object detection and classification, the INVENTORY package
    irac2        Reduction programs for the IRAC2 camera 
    long         Reduction of long slit spectra
    optopus      Package to prepare observations with the fibre 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 reduction package, the ROMAFOT software
    spec         Package for 1-dim spectra
    statist      Statistical tests on tables
    surfphot     Deconvolution and rebinning




    The following contexts are available on request from the institutions
    where they have been developed.


    CONTEXT      DESCRIPTION
    ---------    ----------------------------------------------------
    exsas        Analysis of X-ray data from the ROSAT satellite (1)
    iue          IUE-tape reader                                 (2)


(1) Max Planck Institute for Extraterrestrial Physics in Garching, Germany
(2) ESA Vilspa, Villafranca Satellite Tracking Station, Spain
   
