>Psychtoolbox>PsychColorimetric

output = TriToMetSPD(input,T,B)

Convert tristimulus coordinates in a color space
specified by a set of known color matching
functions to an estimate of the original spectral
power distribtuion.

output - estimated spectral power distribution
(number-of-wavelengths by number-of-lights)
input - source tristimulus vectors
(n-chromacy by number-of-lights)
T - source color matching functions
(n-chromacy by number-of-wavelengths)
B - linear model for spectral power distributions
(number-of-wavelengths by at least n-chromacy)