Useful functions for simulations (created by LW, free to use)

[CreaPhase.git] / utilities_LW / csquare2.m

diff --git a/utilities_LW/csquare2.m b/utilities_LW/csquare2.m
new file mode 100644 (file)
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+++ b/utilities_LW/csquare2.m
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+%# csq=csquare2(beta,f,g) returns cos(pi*beta*(f^2+g^2))
+%# beta is equal to lambda*D/l^2, i.e. the Fresnelnumber
+%# for the complete spectrum (from 0 to fsample)
+%# f_isall = 0
+%# only f and g from 0 to fsample/2 should be given, the other part is 
+%# calculated using the periodicity in frequency-space
+%# f_isall = 1
+%# complete frequency range is given
+%# allows for astigmatism (5th argument)
+
+function csq=csquare2(betah,f,g,varargin)
+
+f_isall = 0;
+switch nargin
+case 3
+    betav = betah;
+case 4
+    f_isall = varargin{1};
+    betav = betah;
+case 5
+    f_isall = varargin{1};
+    betav = varargin{2};
+end
+
+csq=cos((pi*betah)*f.^2+(pi*betav)*g.^2);
+
+if (f_isall~=1)
+    [n m]=size(f);
+    n=n-1;
+    m=m-1;
+    csq=cat(2,cat(1,csq,flipdim(csq(2:n,:,:),1)),cat(1,flipdim(csq(:,2:m,:),2),flipdim(flipdim(csq(2:n,2:m,:),1),2)));
+end
+
+end