Liveplotting a function of a ColumnDataSource

[Bryan]

@reubenharry

All I want to do is plot that function of the source data, and have it change accordingly as I update self.source.data in the periodic callback. Is that possible, or is there a better way?

I think you are asking if Bokeh has features to automatically compute and display summary statistics or other derived quantities? If so, the answer is no, you need to compute those things, yourself. This recent answer in another thread seems relevant

Window-smoothing widget for line plots?

Just for some context, at this stage Bokeh mostly confines itself to computations on data only for things that are directly relevant for rendering, e.g scale transforms, color mapping, grouping, etc.with only a handful of notable exceptions for instances where preparing the data correctly itself is a challenge. [1] We have our hands full enough with the plotting and interactions, so we leave opinionated “non-vis” features to others. [2] If you want analytical functions on the “Python side” we …

Since you are already using Python the very simplest thing to do is just compute those things in your callback, and update (other) ColumnDataSource objects that drive glyphs that display those things. It’s almost certainly possible to figure out something that does the computations with a CustumJS but I don’t see what that effort would gain you here.