kapteyn 2.3.1

The Kapteyn Package is a collection of Python modules and applications developed by the computer group of the Kapteyn Astronomical Institute, University of Groningen, The Netherlands. The purpose of the package is to provide tools for the development of astronomical applications with Python.

The package is suitable for both inexperienced and experienced users and developers and documentation is provided for both groups. The documentation also provides in-depth chapters about celestial transformations, spectral translations and non-linear least squares fitting.

The package’s most important features:

• The handling of spatial and spectral coordinates, WCS projections and transformations between different sky systems. Spectral translations (e.g., between frequencies and velocities) are supported and also mixed coordinates. (Modules wcs and celestial, Module wcs uses Mark Calabretta’s WCSLIB which is distributed with the package.)

• Versatile tools for writing small and dedicated applications for the inspection of FITS headers, the extraction and display of (FITS) data, interactive inspection of this data (color editing) and for the creation of plots with world coordinate information. (Module maputils) As one example, a gallery of all-sky plots is provided.

• A class for the efficient reading, writing and manipulating simple table-like structures in text files. (Module tabarray)

• Utilities for use with matplotlib such as obtaining coordinate information from plots, interactively modifiable colormaps and timer events (module mplutil); tools for parsing and interpreting coordinate information entered by the user (module positions).

• A function to search for gaussian components in a profile (module profiles) and a class for non-linear least squares curve fitting (module kmpfit)