function c = FastRealFourierAnalysis(x,w,pars2,pars3) % FastRealFourierAnalysis -- Real Fourier transform for 1D signals % Usage % c = FastRealFourierAnalysis(x,w) % Inputs % x 1-d signal: length(x)=2^J % w window width % Outputs % c Real Fourier coefficients % Description % c contains coefficients of the Real Fourier Decomposition. % See Also % FastRealFourierSynthesis, fft, ifft % [n,J] = dyadlength(x); d = floor(n/w); c = zeros(n,2); for p=0:d-1 xft = fft(x(p*w+1:(p+1)*w))*sqrt(2/w); c(p*w+1:(p+1)*w,1) = real(xft(:)); c(p*w+1:(p+1)*w,2) = imag(xft(:)); end c = c(:);