function T = BaylorNomogram(S,lambdaMax) % T = BaylorNomogram(S,lambdaMax) % % Compute spectral sensitivities according to the % nomogram provided in Baylor, Nunn, and Schnapf, 1987. % % The result is in quantal units, in the sense that to compute % absorptions you want to input incident spectra in quanta. % To get sensitivity in energy units, apply EnergyToQuanta(). % % Argument lambdaMax may be a column vector of wavelengths. % % 6/22/96 dhb Wrote it. % 10/16/97 dhb Add comment about energy units. % These are the coefficients for the polynomial % approximation. aN = [-5.2734 -87.403 1228.4 -3346.3 -5070.3 30881 -31607]; % Get wls argument. wls = MakeItWls(S); [nWls,nil] = size(wls); [nT,nil] = size(lambdaMax); T = zeros(nT,nWls); wlsum = wls/1000; for i = 1:nT wlsVec = log10( (1 ./ wlsum)*lambdaMax(i)/561)'; logS = aN(1) + aN(2)*wlsVec + aN(3)*wlsVec.^2 + aN(4)*wlsVec.^3 + ... aN(5)*wlsVec.^4 + aN(6)*wlsVec.^5 + aN(7)*wlsVec.^6; T(i,:) = 10.^logS; end