Hexbin for holoviews

It would be nice to have a HoloViews equivalent of the hexbin package ( https://github.com/edzer/hexbin ), which is an extension package originally made for R. This provides binning and plotting functions for hexagonal bins and is an alternative to the point/scatter plot. Its main feature/advantage compared to the conventional scatter plot is the ability to give a better visual feedback of the density of the points.

(edit) Existing implementations for python packages:

• matplotlib
• pandas
• seaborn

It seems to already have an interface to rbokeh, see: http://ryanhafen.com/blog/plot-lots-of-data https://rdrr.io/cran/rbokeh/man/ly_hexbin.html

[philippjfr]

Now merged.

[philippjfr]

Here’s initial prototypes for both the matplotlib and bokeh implementations:

https://anaconda.org/philippjfr/hexbins/notebook

This will need some more discussion though because since aggregation doesn’t happen until plotting there is no way to normalize the color range automatically. If we had a more efficient representation for patches I’d consider storing it that way and making hexbin an operation, but I’m also considering something similar to the HeatMap element, which holds both the raw and the aggregated gridded data. The plot looks just at the aggregated data but you can apply all the usual slicing and other methods to the underlying raw data because these methods will create clones which will recompute the aggregated view. That’s also problematic though because then we depend on matplotlib to do the hexagonal aggregation and the Element can’t be created without it. Not sure what the best thing to do is yet.