Hi, I just tried compiling with the latest cvs, and I had to add: #ifndef FLT_MIN #define FLT_MIN 1.17549435e-38f #endif #ifndef FLT_MAX #define FLT_MAX 3.40282347e+38f #endif to the top of thinplatespline.cpp to get it to compile. It seems FLT_MIN/FLT_MAX are not always defined by the default headers. Gillian