Daylight coefficients

The concept of daylight coefficients is introduced, mathematical functions that relate the luminance distribution of the sky to the illuminance at a point in a room. They are illustrated first in the context of standard daylight calculations, and then in the form of finite element matrices. Graphs of the functions enable effects of sky luminance changes to be appreciated qualitatively; use of the coefficients in computer programs gives an efficient method for calculating daylight from a number of sky brightness distributions in succession.