ꥹ2-5-3.txt

ꥹ2-5-3

60Hzξ

nagasm-Mac-mini:Desktop nagasm$ cat calc_coef.c

#include <stdio.h>
#include <stdlib.h>
#include <math.h>
int main(){
	int fs = 10000;
	double  B0, a1, a2, b1, c0, F0, T;
	F0 = 60;
	B0 = 100.;
	T  = 1./fs;
	a1 = 2. * exp(-M_PI * B0 * T) * cos(2. * M_PI * F0 * T);
	a2 = -exp(-2. * M_PI * B0 * T);
	b1 = -2. * cos(2. * M_PI * F0 * T);
	c0 = (1.-a1-a2)/(2.+b1);
	printf("a1 = %f\n", a1);
	printf("a2 = %f\n", a2);
	printf("b1 = %f\n", b1);
	printf("c0 = %f\n", c0);
	return 0;
}

nagasm-Mac-mini:Desktop nagasm$ gcc calc_coef.c
nagasm-Mac-mini:Desktop nagasm$ ./a.out
a1 = 1.936768
a2 = -0.939101
b1 = -1.998579
c0 = 1.642174

50Hzξ

nagasm-Mac-mini:Desktop nagasm$ cat calc_coef.c

#include <stdio.h>
#include <stdlib.h>
#include <math.h>
int main(){
	int fs = 10000;
	double  B0, a1, a2, b1, c0, F0, T;
	F0 = 50;
	B0 = 100.;
	T  = 1./fs;
	a1 = 2. * exp(-M_PI * B0 * T) * cos(2. * M_PI * F0 * T);
	a2 = -exp(-2. * M_PI * B0 * T);
	b1 = -2. * cos(2. * M_PI * F0 * T);
	c0 = (1.-a1-a2)/(2.+b1);
	printf("a1 = %f\n", a1);
	printf("a2 = %f\n", a2);
	printf("b1 = %f\n", b1);
	printf("c0 = %f\n", c0);
	return 0;
}
nagasm-Mac-mini:Desktop nagasm$ gcc calc_coef.c
nagasm-Mac-mini:Desktop nagasm$ ./a.out
a1 = 1.937188
a2 = -0.939101
b1 = -1.999013
c0 = 1.938304

