twid.c

来自「基于ADSP-219x系列的时间抽取基2FFT代码」· C语言 代码 · 共 40 行

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

main()
{
    int i, n;
    double freq, c, s;
    double pi;
    FILE *s_file;
    FILE *c_file;
    char filename1[25]="twid_real.dat";
    char filename2[25]="twid_imag.dat";
    pi = 4.0*atan(1.0);
    printf("Enter the number of points:");
    scanf("%d",&n);
    n=n/2;
    c_file=fopen(filename1,"w");
    s_file=fopen(filename2,"w");
    freq=2.0*pi*0.5/(double)n;
    fprintf(s_file,"%s\n","0.000000r,");
    fprintf(c_file,"%s\n","0.999999r,");
    for (i=1; i<=n-1; i++)
	{
        s=-sin((double)i * freq);
        c=cos((double)i * freq);
		if(i<n-1)
		{
			fprintf(s_file,"%f%c%c\n",s,'r',',');
            fprintf(c_file,"%f%c%c\n",c,'r',',');
		}
		else
		{
            fprintf(s_file,"%f%c\n",s,'r');
            fprintf(c_file,"%f%c\n",c,'r');
		}
	}
    fclose(s_file);
    fclose(c_file);
    printf("\nFinished\n");
}