elaird/supy — pull request #176 by betchart (2013-04-03 20:06:34+00:00)
Title: optional predicate step in reweights

Due to a new requirement of my analysis, I need to plot my signals after two incompatible cuts, so I have added a predicate in this step for convenience. The theme of predicates could be expanded, for example, I can imagine a more general "steps.other.predicate" step, taking a step to execute along with a "temporary cut" step as a predicate. We originally designed supy purposefully with linear cut-flow, due to conceptual and coding simplicity, and those reasons may still apply. Feel free to merge this branch or expand on the theme.