> doing everything possible in terms of vectors and never using angle measure unless interfacing with humans or legacy software is a generally good idea More g

> doing everything possible in terms of vectors and never using angle measure unless interfacing with humans or legacy software is a generally good idea More generally, use scalar products instead of angles. Calculations based on scalar products are faster, numerically more accurate, simpler, and easier chained. Convert from/to angles only for input/output. Even more generally, always use sane representations internally, and press cumbersome stuff to the borders of your system. Examples: - You should use unicode strings internally, and decode/encode only on I/O. - You should use simple, native data structures internally, and deal with XML representations only at the boundaries. - And so on.