The Siacci methods needs a parametrization in the form of d= 1461.5128 * a*v^b (or something like that, i have to look it up) where d is the drag function and v is the (metric) velocity. I calculate with the aid of some logarithms the constants a and b from the tabulated d's and their metric velocities. This is done for the ICAO velocity of sound. One could say that there is a powerlaw interpolation deployed, although the powerlaw behaves almost linearly in the interval

Presently the only way to correct for temperatures other than ICAO is through adaption of the BC (with bfx_c), there is now no way to communicate the temperature from the excel "space" to the procedure that uses the mach value to compute drag. At the moment it would require to incorporate the temperature in every BfX function - making them awkward. I am expecting to introduce a "table" (a range in excel) for bc. This table contains then the bc, temperature, humidity and pressure, making BfX_C superflous yet keeping the formulas simple. This would be a rather straightforward thing to do now the ground breaking work with the drag tables has been done. However, I find the 6dof implementation much more attractiveto work on - this will happen before X mas I hope. Before that, however, I want to implement neural network software in Excel. Not only do I need it for something else, I think it can be handy for 6dof speedup and - in a far future - the implementation of software that does the aerodynamics on a more elementary level than what we do with bc's and tables.

the m (3, 2) I added later, and was not included in the screenshot of the prototype you saw on the forum. (However I have to include it in BfX_help() )

For what are you using the drag functions?