NEWS.md
This is the inaugural release. It contains several basic plotting layers and associated themes, with a small data set and two vignettes for illustration.
The geom_barcode() layer takes persistence data with the two required aesthetics start (or xmin) and end (or xmax) and produces a barcode diagram, which can optionally be grouped and color-coded by an additional variable (usually dimension).
The stat_persistence() and stat_frontier() layers also take persistence data, though they only accept the required aesthetics start and end. They transform these data into the coordinates of a persistence diagram and into the endpoints of line segments that outline the persistence frontier, respectively. They can be oriented according to “flat”, diagonal, or landscape formats.
The themes theme_persist() and theme_barcode() format plots to resemble the persistence and barcode diagrams found in the literature.
The stat_disk(), stat_vietoris*(), and stat_cech*() layers can be used to visualize the raw mathematical elements of persistent homology on a point cloud in the coordinate plane. By default, they use the geom_face() layer, which is equivalent to geom_polygon() but with different aesthetic defaults.