Phil,
simple awk script to do the arithmetic. If dimensional analysis had been available, it would have been a useful confidence builder that the code was doing the right thing. The problem was this: I have measured the temperatures on the surfaces of an electrical device - a power supply - and I want to calculate the power dissipated. The maths is simple: power = temperature difference to atmosphere * area * heat transfer coefficient. I tried to write this using the units library.
If you don't need to store the heat transfer coefficient, you can make this a one-liner without worrying about the type of the HTC itself (assuming you've defined quantities for dT and A already) : quantity<power> P = dT*A*7.5*watts/kelvin/square_meter; Matthias