function [isomerizationRate] = IsomerizationsFromAbsorptions(photonAbsorptionRate,quantalEfficiency)
% [isomerizationRate] = IsomerizationsFromAbsorptions(photonAbsorptionRate,[quantalEfficiency])
% 
%	Compute isomerization rate, R* per photreceptor per sec, given 
% photon absorption rate and photopgiment quantal efficiency.
%
% Default value for quantalEfficiency is inherited from PhotopigmentQuantalEfficiency
% called with type 'Generic'.
%
% 06/11/03 lyin		Rewrote it.
% 06/23/03 dhb		Change name, made quantalEfficiency an argument. 
% 07/25/03 dhb    Take default value from data routine. 

% Set default efficiency.
if (nargin < 2 || isempty(quantalEfficiency))
	quantalEfficiency = PhotopigmentQuantalEfficiency('FovealMCone','Human','Generic')* ...
		ones(size(photonAbsorptionRate));
end

% Compute simple product.
isomerizationRate = photonAbsorptionRate .* quantalEfficiency;