It looks like Node’s child processes cannot always open /dev/stdout, at least on Linux. An error such as "UNKNOWN" or "ENXIO" is thrown. This thread may be related: https://groups.google.com/d/topic/nodejs/SxNKLclbM5k/discussion One workaround is to insert a pipe to cat, which allows the child process to open /dev/stdout, and pipe to cat. Then the output of cat can be read by the test. Fixes #204.
Rather than build one large heap for all arcs, we build a heap for each arc separately and simplify one arc at a time. A quick benchmark using Natural Earth’s 10m admin-0 data simplified at 1e-5 results in a 2x speedup with this change. This is due to reduced peak memory usage and faster heap operations on the smaller heaps.