Inside Autoplot: an Interface for Representing Science Data in Software

Autoplot is software for plotting and manipulating data sets that come from a variety of sources and applications, and a flexible interface for representing data has been developed. QDataSet is the name for the "data model" which has evolved over a decade from previous models implemented by the author. A "data model" is similar to a "metadata model." Whereas a metadata model has terms that describe various aspects of data sets, a data model has terms and conventions for representing data along with conventions for numerical operations. The QDataSet model re-uses several concepts from the NetCDF and CDF data models and has novel ideas that extend the reach to include more types of data. Irregular spectrograms and timeseries can be represented, but also new types like events lists, annotations, tuples of data, and N-dimensional bounding boxes. While file formats are central to many models, QDataSet is an interface with a thin syntax layer, and semantics give structure to data. It's been implemented in Java and Python for Autoplot, but can be easily implemented in C, IDL or XML. A survey of other models is presented, as are the fundamental ideas of the interface, along with use cases. Autoplot will be presented as well, to demonstrate how QDataSet and QDataSet operators can be used to accomplish science tasks.