comparison functions/idceps.m @ 0:b4e26b53072f tip

Initial commit.

+function X = idceps(c, w)
+% X = idceps(c, w)
+%
+% computes the inverse discrete cepstrum, i.e. given a number of discrete 
+% cepstral coefficients, it returns the spectrum.
+%
+% c contains the discrete cepstral coefficients
+% w contains the frequency at which the spectrum is evaluated.
+% c and w must be column vectors.
+%
+% Further details can be found in:
+% [1] Diemo Schwarz. Spectral envelopes in sound analysis and synthesis.
+% Master's thesis, Universitaet Stuttgart, 1998, pp. 36-38.
+% [2] T. Galas and X. Rodet. An improved cepstral method for deconvolution
+% of source filter systems with discrete spectra: Application to musical
+% sound signals. In International Computer Music Conference, 1990.
+
+pmax = length(c)-1;
+numW = length(w);
+
+exponent = sum(  repmat(c', numW, 1) .* cos(w*(0:pmax)), 2  );
+X = exp(exponent);