integrate `legendgram` into `mapclassify`?

[jGaboardi]

xref pysal/legendgram#21

[martinfleis]

This was briefly discussed in #216 and I guess that it could simply end up as an extension of that function, no?

[jGaboardi]

So considering #234 & #250:

1. Can this issue be closed?
2. Should we begin ramping down legendgram for archival?

[knaaptime]

yes, yes

only question is whether we want to keep both plot_legendgram and plot_histogram since we don't really need the latter anymore

[jGaboardi]

yes, yes

only question is whether we want to keep both plot_legendgram and plot_histogram since we don't really need the latter anymore

If we don't need, let's go ahead and dump it?

@sjsrey @martinfleis – thoughts here?