Crates and Transform: Python Interfaces for Data Analysis

With its flexible design and ease-of-use, Crates and Transform have been incorporated into the Chandra X-Ray Center's (CXC) data visualization and fitting tools and data processing scripts to facilitate a wide variety of tasks. Chandra's fitting and modeling application, called Sherpa, uses Crates as an underlying data access module, taking advantage of its ability to interpret standard Flexible Image Transport System (FITS) files, such as Redistribution Matrix Files (RMF), Auxiliary Response Files(ARF), and both types of Pulse Height Analysis (PHA) files. The Chandra Imaging and Plotting System (ChIPS) tool utilizes the associated Transform module for visualizing data in different World Coordinate Systems (WCS). By using the CXC DataModel (DM) as a backend, Crates can perform advanced filtering and binning techniques on data. This capability, combined with its simple Application Programming Interface, make it ideal for incorporation into our data analysis scripts, aiding with operations from simple keyword manipulation to creating and writing multiple Header Definition Unit (HDU) files. Crates and Transform are available respectively as the pycrates and pytransform modules within the Chandra Interactive Analysis of Observations (CIAO) environment to assist users with their own analysis threads. In this paper, we will illustrate the capabilities of the Crates and Transform modules and how they are being used within the CXC for analysis.