Matlab contour plots with transparent backgrounds?

Hi. This is Nat Hamlin. I'm wondering how to use Matlab to make contour plots (of magnetic field lines) with transparent backgrounds. Specifically, the input file generally contains data for multiple contour plots, and I would like to be able to generate the plots, and the output files, sequentially using a "for" loop. The purpose of this is to then overlay these plots, with transparent backgrounds, onto gray-scale or color displays of a different quantity that in many cases have been created in a different program. Thanks.

Answer 1

[Walter Roberson]

contour() and contourf() produce a hggroup object which has patch objects as its children. You can set the alpha characteristics of patch objects in various ways; see here