Real-time graphs

[Doug Holton]

snrkiwi-lists at yahoo.com wrote:

> I've trolled the lists, FAQs, and Net as a whole, but
> can't find anything definitive to answer this.
> 
> We're looking for real-time graph capability (bar,
> line, etc), so that we can display telemetry from a
> robot system.  There are a bunch of packages out
> there, but many seem to provide only static graphs
> (e.g. for scientific, financial data, etc). Does
> anyone currently display real-time telemetry using
> Python? Can anyone provide any suggestions?

Unfortunately there is not anything designed specifically for
real-time graphs in python.  You could create a custom control.

My suggestion is to use a Timer (like wx.Timer in wxpython) set to a 
particular "frame rate" - how many times the graph should be refreshed 
per second.  Everytime it fires it updates the graph (if it is a 
scrolling plot, or else if the data has changed).  Meanwhile in a 
background thread your time-stamped data points are collected, perhaps 
into two lists.  If it is a scrolling plot you could discard (or log) 
data that is old.