/usr/share/psychtoolbox-3/PsychOptics/AiryPattern.m is in psychtoolbox-3-common 3.0.11.20131230.dfsg1-1build1.
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 | function intensity = AiryPattern(angles,pupil,nm)
% intensity = AiryPattern((angles,pupil,nm)
%
% Compute the radial Airy pattern for diffraction by
% a circular aperature.
%
% "angles" visual angle in radians
% "pupil" diameter in mm
% "nm" is wavelength in nm
%
% Intensity is normalized to max of 1.
%
% Formulae from Hecht, Optics, 2cd edition, p. 419.
%
% 1/13/04 dhb Wrote it.
% 12/27/04 dhb Deal with case of input == 0.
% Compute radius in nm
a = (pupil/2)*10^6;
% Compute wavenumber
k = 2*pi/nm;
% Compute out airy pattern
besselarg = k*a*sin(angles);
intensity = ones(size(angles));
index = find(besselarg ~= 0);
if (~isempty(index))
intensity(index) = abs((2*besselj(1,besselarg(index))./besselarg(index))).^2;
end
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