>Psychtoolbox>PsychColorimetricData

T_absorbance = CarrollNeitzNomogram(S, lambdaMax)

Compute normalized absorbance according to the nomogram of
Carroll, McMahon, Neitz, & Neitz (2000), J. Opt. Soc. Am. A, 17(3), 499-509.

T_absorbance contains the absorbance (not log absorbance).
The CVRL convention is used: absorbance = log(I_incident/I_transmitted),
so values are positive, with a peak of 1. The peak is normalized
explicitly to 1 when wavelength spacing S(2) <= 1 nm.

The result is in quantal units. To get sensitivity in energy units,
apply EnergyToQuanta().

Argument lambdaMax may be a column vector of lambda max values, in which
case T_absorbance is nLambdaMax x nWls.

The nomogram is parameterized relative to a reference lambda max of
558.5 nm. The internal shifted frequency variable is
x = lambdaMax / (558.5 * wl)
which is analogous to the ratio form used by the Govardovskii nomogram.

Reasonable lambda max values for (L, M, S): 557.5, 530, 420 nm.
These values are from Neitz & Neitz (2011), who report good agreement
between this template and CIE cone fundamentals derived from color matching
at these peaks; see their Figure 3 and surrounding text.
Neitz, J. & Neitz, M. (2011). The genetics of normal and defective
color vision. Vision Research, 51, 633-651.

See also CarrollNeitzNomogramTest, PhotpigmentNomogramDemo.