/usr/share/psychtoolbox-3/PsychOptics/GoodmanDiffrac.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 | function mtf = GoodmanDiffrac(s,s0)
% mtf = GoodmanDiffrac(s,s0)
%
% Compute Equation 6-31 from page 120 of Goodman.
% This is the diffraction-limited optical MTF,
% computed given the coherent diffraction limit s0.
%
% Goodman, J. W. (1968) Introduction to Fourier Optics.
% San Francisco: McGraw-Hill.
%
% Note that in the Williams et al. paper (ref??), this
% formula is given for the incoherent diffraction limit,
% which is twice the coherent limit.
%
% Also see DiffractionMTF.
% 7/11/94 dhb Added some comments, changed variable names
% 1/27/01 dgp Cosmetic.
% 9/8/02 dgp Cosmetic.
mtf = zeros(size(s));
factor = zeros(size(s));
index = find(s <= 2*s0);
temp = ones(size(s(index)));
factor(index) = s(index) ./ (2*s0);
mtf(index) = (2/pi)*( acos(factor(index)) - factor(index).*sqrt(temp-factor(index).^2) );
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