Short description: Like the helix family from a couple weeks ago, these files allow you to load either a curve or a surface and manipulate them purely by math. Look Ma, No API! These are 100% good old fashion parameter driven loaded families.
I don't have the time now to really describe them, but I thought I would put them up for your dissection and inspection. I'll try and do an update with simplified interface. At the moment, you have to do a lot of correction for units, which is sort of a drag. Also, if you want to do something really complex, you will need to add more points.
General how-to operate these files: the formula driven spline, you can open up loaded family 'formulaPoint' for edit, and change the formula that drives the parameter 'y'. Reload and presto: a new curve. For the formula driven surface, open 'formula3dPoint' for edit and change the formula for parameter 'z'. I have included a couple other formulas in dummy parameters in the family for you to play with, just cut and paste into the y or z parameter
Download from HERE.
More to come