test32.cpp

这是我本人编写的一个32位定点小数运算的函数库。对于没有浮点运算器的场合

// test32.cpp : Defines the entry point for the console application.
//

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

#define M       10
#define N       (1<<M)
#define H		2000

long fix_fft32(long fr[], long fi[], int m, int inverse);

main()
{
        long real[N], imag[N];
		long data[N];
        int     i;

        for (i=0; i<N; i++){
                data[i]=real[i] = H*cos(i*2*3.1415926535/N);
                imag[i] = 0;
        }

        fix_fft32(real, imag, M, 0);
        fix_fft32(real, imag, M, 1);
		long md=0,sum=0;
		for (i=0;i<N;i++) {
			long s=abs(data[i]-real[i]);
			if (s>md) md=s;
			sum+=s;
		}
		printf("Max delta=%lf\tAver delta=%lf\n",(double)md/H,(double)sum/N/H);
		getch();
		return 0;
}