trolands =
QuantaToTrolands(wl,quanta,S_vLambda,vLambda)
Convert from quanta (sec-1 deg-2) to to trolands for a
monochromatic light.
See W&S, p. 103.
8/15/96 dhb, abp Wrote the header.
8/22/96 dhb Wavelength should be in meters.
Psychtoolbox/PsychColorimetric/QuantaToTrolands.m