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function y = cceps (x,correct)
//Return the complex cepstrum of the vector x
//Calling Sequence
//cceps (x)
//cceps(x, correct)
//Parameters
//x: vector.
//correct: if 1, a correction method is applied.
//Description
//This function return the complex cepstrum of the vector x. If the optional argument correct has the value 1, a correction method is applied. The default is not to do this.
//Examples
//cceps([1,2,3],1)
//ans = 1.9256506
// 0.9634573
// - 1.0973484
if(argn(2)<1 | argn(2)>2)
error("Wrong number of input arguments.")
end
if argn(2)==1 then
correct=0;
end
[r, c]=size(x)
if (c ~= 1)
if (r == 1)
x = x;
r = c;
else
error ("x must be a vector");
end
end
F = fft1(x);
if (min (abs (F)) == 0)
error ('bad signal x, some Fourier coefficients are zero.');
end
h = fix (r / 2);
cor = 0;
if (2 * h == r)
cor = (c & (real (F (h + 1)) < 0));
if (cor)
F = fft1 (x(1:r-1))
if (min (abs (F)) == 0)
error ('bad signal x, some Fourier coefficients are zero.');
end
end
end
y = fftshift1 (ifft1 ((log (F))'));
//## make result real
if (c)
y = real (y);
if (cor)
// ## make cepstrum of same length as input vector
y (r) = 0;
end
end
endfunction
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