3.1. Topology of the data-flow graph¶

The pattern used for constructing the data-flow graph is described in detail in the subsystem design (under preparation). Here we discuss the overall topology of the workflow, using the graph in Fig. 3.1.

The graph-node candidates are separated into various classifications:

creators

algorithms that create data (e.g transforms, folds, and unfolds)

predicates

algorithms that return a Boolean value upon each invocation; each predicate serves as the operator to a filter operation

observers

algorithms that accept data products as input arguments but do not create new data products