[matplotlib-devel] New plot type idea -- EventRaster

[Todd <tod...@gm...>]

I would like to add a new plot type to matplotlib.  Of course I am willing
to implement it myself, but I want to confirm that it is acceptable and
iron out the implementation details and API first so there are no major
surprises when I submit it.

I tentatively am calling the plot type an "EventRaster" plot (name
suggestions, along with any other suggestions, are welcome).  The plot is
made up if horizontal rows of identical vertical lines and/or markers.
Each line or marker represents a discrete event, and each row represents a
single sequence of events (such as a trial).  The x-axis position of the
line or marker identifies the location of the event by some measure.  An
example of what such a plot often looks like is below.

http://hebb.mit.edu/courses/9.29/2003/athena/dylanh/quad-rast.gif

This sort of plot is used ubiquitously in neuroscience.  It is used to show
the time of discrete neural (brain cell) events (called "spikes") over time
in repeated trials, and is generally called a spike raster, raster plot, or
raster graph.  However, it can be used in any situation where you are only
concerned with the position of events but not their amplitude, especially
if you want to look for patterns in those events or look for differences
between multiple sequences of events.

Plotting the timing of events is an obvious use case, such as photons
hitting photodetectors, radioactive decay events, arrival of patients to
hospitals, calls to hotlines, or car accidents in cities.  However, the
events do not have to be relative to time.  It could be position, for
example, such as tree rings along bore holes, road crossings along railroad
tracks, layers in sediment cores, or particular sequences along a DNA
strands.

I'll cover possible implementation details in the next email if everyone
thinks this is a good idea.