Chrip-z Test.jl

# function czt( x::Vector )
    x = ones(8)
    N  = length( x )
    M  = nextpow2( 2*N - 1 )
    xx = zeros( Complex128, M ) 
    yy = zeros( Complex128, M )    

    for n = 1:N
        xx[n] = x[n]
        yy[n] = exp( im * π/N * (n-1)^2 )
    end
    
    for n = 1-N:-1
        yy[M+n+1] = exp( im*π/N*n*n )
    end 
    
    for n = 1:N
        xx[n] = x[n]*exp( -im*π/N*(n-1)^2 )
    end
    
    XX = fft( xx )
    YY = fft( yy )
    X  = XX.*YY
    X  = ifft( X ) 
    
    X  = [ X[n] * exp( im*π/N*(n-1)^2 ) for n = 1:M ]
    X  = X[1:N]
# end