4 cp PJ_isea.c path/to/proj-4.7.0
6 patch -p1 < ../isea/proj4.patch
8 now build proj.4 as usual for your system
12 There is too much numerical instability to try to project directly with postgis.
13 The interruptions make it almost impossible to reconstitute the input polygons.
15 Might be able to do it by computing segments, and then ordering the segments
21 Aperture will set the scaling property
23 Resolution is either the resolution level for the given aperture,
24 or the total number of hexes along a triangle side if aperture is zero.
26 I think the ISEA plane projection is offsetting to avoid negative Y coords.