draw.c.txt

我的数字信号处理 作业。FFT的C语言实现。运行时将2个c文件放在同一目录

#include "graphics.h"
#include "math.h"
#include "yin_fft.c"
#define pi  3.142

main()
{
  int i,fs,N1,N2,XX;
  int driver=DETECT,gmode;
  float xr[32];
  float xi[32],xi2[32];
  fs=64,N1=16,N2=32,XX=40;
  initgraph(&driver,&gmode," ");
  for(i=0;i<32;i++){
    xi[i]=0;xi2[i]=0;
    }
  for(i=0;i<N1;i++)
     xr[i]=cos(8*pi*i/fs)+cos(16*pi*i/fs)+cos(20*pi*i/fs);
  for(i=0;i<N1;i++)
    line(XX+i*10,150,XX+i*10,150-(int)(40*xr[i]));
  yin_fft(xr,xi,N1);
  moveto(XX,400-(int)(10*sqrt(xr[0]*xr[0]+xi[0]*xi[0])) );
  for(i=0;i<N1;i++)
    lineto(XX+i*10,400-(int)(10*sqrt(xr[i]*xr[i]+xi[i]*xi[i])) );

  XX=300;
  for(i=0;i<N2;i++)
     xr[i]=cos(8*pi*i/fs)+cos(16*pi*i/fs)+cos(20*pi*i/fs);
  for(i=0;i<N2;i++)
    line(XX+i*10,150,XX+i*10,150-(int)(40*xr[i]));
  yin_fft(xr,xi2,N2);
  moveto(XX,400-(int)(10*sqrt(xr[0]*xr[0]+xi[0]*xi[0]))) ;
  for(i=0;i<N2;i++)
    lineto(XX+i*10,400-(int)(10*sqrt(xr[i]*xr[i]+xi2[i]*xi2[i])) );

    getch();
}