Introduction - If you have any usage issues, please Google them yourself
Below is the Matlab code to find radix-2 FFT butterfly twiddle factors. The code computes the A phase angle factors that are used in the twiddle factors as shown in Figure 1(c) and Figure 2(c). I suggest you start by running the code for the 8-point DIT FFT in Figure 1(a) and then run the code for the 16-point DIF FFT in Figure 2(a).