VIZ-10-003: Asymptote: heatmap

Unpack this archive and run from its directory:
asy -safe -noView -nobatchView -nointeractiveView -render 0 -noprc -nov3d -tex pdflatex -f pdf -o VIZ-10-003 VIZ-10-003.asy

Data columns and chart conventions are explained in the companion tour.
