scaling glyphs in data units (not screen units)
Markers (e.g. Triangle) are really meant for use as "scatter" plot markers. With the exception of Circle, they only accept screen dimensions (pixles) for size. If you need triangular regions that scale with data space range changes, your options are to use patch or patches to draw the triangles as polygons (either one at a time, or "vectorized", respectively)
I am plotting both wedges and triangles on the same figure.  The wedges scale up as I zoom in (I like this), but the triangles do not (I wish they did), presumably because wedges are sized in data units (via radius property) and traingles are in screen units (via size property).
Is it possible to switch the triangles to data units, so everything scales up during zoom in?
I am using bokeh version 0.12.4 and python 3.5.2 (both installed via Anaconda).