Formulas!

Anyone have any good knowledge on this?
I am going to attempt to make a formula within revit for average daylight calculation.
I am going to attempt to make a formula within revit for average daylight calculation.
DF = MWuT/A(1 – R2)
Where:
W = total glazed area of windows or roof lights
A = total area of all the room surfaces (ceiling, floor, walls and windows)
R = area-weighted average reflectance of the room surfaces
M = a correction factor for dirt
T = glass transmission factor
u = angle of visible sky
Guide values for a typical dwelling with light-coloured walls are as follows (for more accurate values, refer to CIBSE Lighting Guide 10):
R = 0.5
M = 1.0 (vertical glazing that can be cleaned easily)
0.8 (sloping glazing)
0.7 (horizontal glazing)
T = 0.7 (double glazing)
0.6 (double glazing with low emissivity coating)
0.6 (triple glazing)
u = 65˚ (vertical glazing)