mangyin.cpp

忙音450HZ的快速检测

#include "math.h"
#include "stdio.h"
double x[106];
void main()
{
	#define  PI   3.1415926
	float coeff;
	float Q1;
	float Q2;
	float Q0;
	float sine;
	float cosine;
    int	  k;
    float	floatN;
    float	omega;
	float Real[106], Imag[106];
	float result[106];
	floatN = 106.0;
	int i,n,j;
	n=106;

	for(i=0;i<n;i++)
	{
		x[i]=sin(900*PI*i/8000.0);
	}

		k=6;
		omega = (float)(2.0 * PI * k) / floatN;
		sine = (float) sin(omega);
		cosine = (float) cos(omega);
		coeff = (float) 2.0 * cosine;
	    Q2 = 0;
		Q1 = 0;
		for(i=0;i<n;i++)
		{
			Q0 = coeff * Q1 - Q2 + (float) x[i];
			Q2 = Q1;
			Q1 = Q0;
		}

		Real[6] = (Q1 - Q2 * cosine);

		Imag[6] = (Q2 * sine);

		result[6] = Real[6]*Real[6] + Imag[6]*Imag[6];

	result[6]=sqrt(result[6]);
	printf("result[6]=%10.7f\n",result[6]/53);

}