> Where is this procedure ( I_compute_georef_equations())? It isn't in > equ.c. I_*() are in lib/imagery/ G_*() are in lib/gis/ R_*() are in lib/raster/ etc $ cd lib/ $ grep -rI "I_compute_georef_equations" * imagery/georef.c:int I_compute_georef_equations( so it is in lib/imagery/georef.c Hamish