Institut für Astronomie und Astrophysik
Abteilung AstronomieSand 1, D-72076 Tübingen, Germany
cafe - introduction
multi-purpose fit environment.
Call in IDL: IDL> cafe [,"logfile"] logfile - (optional) the file name of a log file to which all operations and results will be written into. This will start the cafe fit environment. To leave enter "quit".
CAFE is intended for the "every day fitting" for arbitrary data sets. Written in the interactive data language IDL (refer rsi corporation at www.rsinc.com) it could easily be adopted/expanded for personal purposes. Especially it is possible to define arbitrary models and to add specialized commands. The cafe environment supports: - text/fits file data reading - loading several data sets in distinct groups - combining standard models in algebraic expressions - defining separate models for each data group - perform fit process for non-linear functions - perform a joint fit with different models/data sets - fix parameters - ignore/allow data points for fitting - plot result with several types of residuum - simple batch processing - sophisticated plotting with interface to all IDL plot commands. - saving/printing results - online help for all commands and subcommands With some restrictions it is possible to perform multi dimensional fits (by using models which project the x dimensions to a 1-d output). For reading and plotting there are drivers (dat2/data2/model2) to deal with 3-dim data. The cafe environment is not intended for automatic fit processes. Due to the interactive approach the data sets should be medium sized. The CAFE environment does not reinvent the wheel (though it is a intriguing challenge to do that - both the wheel and a fitting program). The heart of the program - the fitting algorithm - is implemented by Craig Marquardts mpfit library (refer http://cow.physics.wisc.edu/~craigm/idl/idl.html). Also error computations are taken from the astronomical library at the IAAT. Therefore this environment acts rather as an user interface to allow standard fitting processes. The syntax and appearance resembles the one of the xspec spectral fit program to come faster along with this program.
Further information may be get with the online help function. Call > help to get a complete list of commands/topics. > help, topic returns closer information.
This environment was built at the Institute for Astronomy and Astrophysics Tuebingen (IAAT), http://astro.uni-tuebingen.de). Design, structure and basic commands are created by Eckart Goehler, 2002. The software may be copied and distributed for free following the terms of the free software foundation.
$Id: cafe_cafe.pro,v 1.9 2003/05/13 08:07:18 goehler Exp $
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