1. Introduction

1.1. Overview

The DRAGONS Recipe System is Gemini Observatory’s data processing automation platform. The Recipe System is designed to accommodate both stepwise, interactive data processing, and automated data reduction pipelines.

The Recipe System inspect the inputs and automatically associates the recipes and primitives most appropriate for those inputs. A primitive is a step in a reduction, for example biasCorrect. A recipe is a sequence of primitives. For the Gemini instruments, the collections of primitives and recipes are found in the geminidr package. It is possible to specify a different data reduction package.

The Recipe System relies on the Astrodata facility (astrodata package) to identify the input data and match them to the recipes and primitives. The Astrodata tags are the keys to the mapping. For the Gemini instruments, the Astrodata configurations are found in the gemini_instruments package. Again, it is possible to specify a different Astrodata configuration package.

The reduce command and programmatic access to the Reduce class are the principle ways DRAGONS users can employ the Recipe System to process and reduce their data. This document discusses a variety of examples of the reduce command line and the programmatic interface on the Reduce class.

The reduce command, and its programmatic interface, support options that allow users to select and “tune” input parameters data processing steps. Without any command line options or adjustment of the Reduce class option attributes, the reduction uses default recipes and default input parameters to the primitives. In the geminidr package, which support the Gemini instruments, the default recipes and primitive parametres have been optimized to give good results in most cases.

A typical reduce command can look deceptively simple. Without knowing the content of the data file, you can simply run reduce on the data and the Recipe System automatically selects the best recipe and primitives based upon the data classifications. For example, a call like this one can be all that is needed:

$ reduce S20161025S0111.fits
                       --- reduce, v2.0 (beta) ---
All submitted files appear valid
RECIPE: reduce
 PRIMITIVE: prepare

1.2. Further Information

Details and information on developing for the Recipe System, and about the astrodata package are available in companion manuals. We invite the reader interested in those topics to refer to the topical documentation.