utilities checklist

[corybrunson]

As we consider whether to divorce routines from utilities (see here), i thought it would be good to lay out the legit utilities (base-R, minimal-dependency tools) we plan or ponder to include in {phutil}. I'm initiating the checklist below with my own ideas. I suggest that cross out (rather than delete) items we decide not to implement and that we keep the issue open until it is exhausted (possibly never).

• plot.persistence(), probably similar to TDA::plot.diagram()
• summary.persistence(), to provide more detail than format() and print()
• tidy.persistence(), glance.persistence(), and possibly other methods for functions from {generics}
• summary functions like total_persistence() and mean_persistence()
• established time series transformations, including the Takens embedding currently unexported in {ripserr} – to be used by {ripserr} but also by e.g. {tdarec} for pre-processing steps