我有以下源代码。据我所知，它应该是 10Hz 的 Bessel LPF。有没有办法从中获得采样频率？

double LPF(register double value) { 
    static double buf[4];
    register double tmp, fir, iir;
    tmp= buf[0]; memmove(buf, buf+1, 3*sizeof(double));
    iir= val * 1.865660386328251e-06;
    iir -= 0.9048452950692862*tmp; fir= tmp;
    iir -= -1.898666438223082*buf[0]; fir += buf[0]+buf[0];
    fir += iir;
    tmp= buf[1]; buf[1]= iir; val= fir;
    iir= val;
    iir -= 0.8712702520352774*tmp; fir= tmp;
    iir -= -1.866439169696869*buf[2]; fir += buf[2]+buf[2];
    fir += iir;
    buf[3]= iir; val= fir;
    return val;
}