how can i get the fractional fourier transform of hamming window function

    if true
    % code
function frft2=frft(f,a)
N=length(f);
%---------interpolation at the begining-------------
f=interpft(f,2*N);
xaxis=(-N/2:N/2-1);
%...............variables for chirp.....................
alpha = a*pi/2;
talpha2 = tan(alpha/2);
sinalpha=sin(alpha);
%..................defining chirp.......................
chirp = exp(-i/N*pi/4*talpha2*(-N:N-1)'.^2);
%...............multiplying with chirp..................
for p=1:2*N-1
f(p)= f(p)*chirp(p);
end
%................convoluting with chirp.................
c = pi/N/sinalpha/4;
chirp2=exp(i*c*(-(2*N):2*N-1)'.^2);
Frft = conv(chirp2,f);
%............post multiplying with chirp................
Frft = chirp.*Frft(2*N:4*N-1);
%............multipling by the gain term...............
Frft = Frft(1:2*N)*exp(-i*pi*sign(sinalpha)/4
+i*alpha/2)/sqrt(abs(sinalpha))/2/sqrt(N);
%..........down sampling Frft to N terms..............
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% length(frft)
frft2=Frft(1:2:2*N);

end

[PRACHI TIWARI]

i also want to do coding of different window function with FRFT.