Comments from Loredo regarding terminology and plotting parameter tweaks

[dfm]

In an email on 2013-11-25, Tom Loredo (Cornell) suggested:

Two suggestions:

• There does not seem to be a universal terminology for these plots, but the terms I see most often are "pairs plots" and "scatterplot matrices" (I'd never seen "corner plot" or "triangle plot" before). I suggest putting these in your README.rst so people will more easily find your solution via a web search.
• One option I have in mine is to plot the posterior samples colored according to time in the chain, and transparent. I use a color map from blue to green to red, or something like that. It provides a graphical 2-D convergence diagnostic: if everything is mixed, the predominant color is brownish; but if the chain gets stuck anywhere, spots of a specific color stand out. In particular, if you don't discard enough "burn in," there is often a blue region sitting away from the brownish region. Probably too busy for a final plot, but helpful when you're exploring/tuning. My statistician collaborators at Duke like this and have started using it.

Thanks Tom!

[tloredo]

And I found yet another term; from http://www2.warwick.ac.uk/fac/sci/moac/people/students/peter_cock/r/iris_plots/ :

"This type of image is also called a Draftsman's display - it shows the possible two-dimensional projections of multidimensional data (in this case, four dimensional). An actual engineer might use this to represent three dimensional physical objects."

And see here for some popular R terminology and packages:

http://www.statmethods.net/graphs/scatterplot.html

This page mentions color-coding cells to indicate strength of correlation; Joe Harrington's exoplanet transit/eclipse group uses that technique.