This example is taken from Chapter 21 of Finite Volume Methods for Hyperbolic Problems
Download directory in compressed tar file format (Note: Please unpack the tar file in your CLAW home directory.)
AMR for the radial dam break problem.
This directory contains a local version of allowflag.f that allows refinement to Level 2 only for y>0 and to Level 3 only for x,y>0 as an illustration of how to use this routine.
Comment out the two lines in allowflag.f where allowflag = .false. to allow refinement everywhere.