#AP NEW DSP Program: DFT

#include <stdio.h>
#include <math.h>

float x[4]={1,3,2,5}; //input only real sequence
main()
{
float y[16]; //for 8 point DFT to store real & imaginary
float w;
int n,k,k1,N=8,xlen=4;
for(k=0;k<2*N;k=k+2)
{
y[k]=0;
y[k+1]=0; //initialize real & imag parts
k1=k/2; //actual k index
for(n=0;n<xlen;n++)
{
w=-2*3.14*k1*n/N;
y[k]=y[k]+x[n]*cos(w);
y[k+1]=y[k+1]+x[n]*sin(w);
}
printf("\n %f+j%f ",y[k],y[k+1]);
}
while(1);
}