Implementing twiddle factor for an radix 2 square fft ??

[sandy3129]

hello everyone i'm implementing twiddle factors for radix 2 square fft, i have actually created my logic controlled by N and level.where N= 16,64,256..,levels are 1,2,3

for m = 0:(((N/4)/(4^(level-1))-1)) % Compute twiddle factors
    tw(1:1+(N/(4^level)),1) =1;  
    tw(((((N/4)/(4^(level-1)))) + 1 )+m) = (cos(2*pi*(m*2)*(1/N)) - (1j*(sin(2*pi*(m*2)*1/N)))));
    tw(((((N/2)/(4^(level-1)))) + 1 )+m) = (cos(2*pi*(m)*(1/N)) - (1j*(sin(2*pi*(m)*(1/N)))));
    tw((((((N/2)/(4^(level-1))))+ (((N/4)/(4^(level-1)))) + 1 )+m)) = (cos(2*pi*(m*3)*(1/N)) - (1j*(sin(2*pi*(m*3)*(1/N)))));
end
tw = repmat(tw,(4^(level-1)),1);

im implementing these twiddle factors and stored in an array at a time,
how can we create twiddle factors variably without storing them in an array for an radix 2 square fft.