mitchell_09, a FreeFem++ code which sets up and solves Mitchell's problem #9, "the wave front".
The computer code and data files described and made available on this web page are distributed under the MIT license
A web site at NIST describes these and many other problems: http://math.nist.gov/amr-benchmark/index.html
mitchell_09a defines the "wave front" problem on the [0,+1]x[0,+1] square with parameters ALPHA = 20, XC = -0.05, YC = -0.05, R0 = 0.7.
mitchell_09b defines the "wave front" problem on the [0,+1]x[0,+1] square with parameters ALPHA = 1000, XC = -0.05, YC = -0.05, R0 = 0.7.
mitchell_09c defines the "wave front" problem on the [0,+1]x[0,+1] square with parameters ALPHA = 1000, XC = 1.5, YC = 0.25, R0 = 0.92.
mitchell_09d defines the "wave front" problem on the [0,+1]x[0,+1] square with parameters ALPHA = 50, XC = 0.5, YC = 0.5, R0 = 0.25.