function[obj h ] = pupil_response_function(obj, t, varargin)
%% Hoeks and Levelt Pupillary Response function
%
%   # n+1 = number of laters
%   # t_max = response maximum
%   # f = scaling factor
if nargin == 2
    n=10.1;
    t_max=930;
    f=1/(10^27);
else
    n = varargin{1};
    t_max= varargin{2};
    f= varargin{3};
end

h = f .* (t.^n) .* exp(-n .*t ./ t_max);
h(1) = 0;