(Reopened) Unexplained behaviour of calibration correction around high concentration of poles and zeros about nanovna-h HOT 1 OPEN

int8_t IS_HARMONIC_MODE(uint32_t freq){
	if (freq > FREQ_HARMONICS * 5 ) {
		return 3;
	}
	else{
		if (freq > FREQ_HARMONICS * 3) {
			return 2;
		}
		else{
		  if (freq > FREQ_HARMONICS) {
			  return 1;
		  }
		  else{
			  return 0;
		  }
		}
	}
}

#if __NewBandChangeInterpolation__ == 1
          float k1 = (float)(f - src->_frequencies[j])
                          / (src->_frequencies[j+1] - src->_frequencies[j]);

          // avoid glitch between freqs in different harmonics mode
          if (IS_HARMONIC_MODE(src->_frequencies[j]) != IS_HARMONIC_MODE(src->_frequencies[j+1])) {
              int m;
        	  if (IS_HARMONIC_MODE(f)==IS_HARMONIC_MODE(src->_frequencies[j+1])){
				  float k0 = 2 - k1;
				  k1 = k1 - 1;
				  for (eterm = 0; eterm < 5; eterm++) {
					cal_data[eterm][i][0] = src->_cal_data[eterm][j+1][0] * k0 + src->_cal_data[eterm][j+2][0] * k1;
					cal_data[eterm][i][1] = src->_cal_data[eterm][j+1][1] * k0 + src->_cal_data[eterm][j+2][1] * k1;
				  }
        	  }
        	  else{
				  float k0 = - k1;
				  k1 = k1 + 1;
				  if (j == 0){
					  m = j;
				  }
				  else{
					  m = j - 1;
				  }
				  for (eterm = 0; eterm < 5; eterm++) {
					cal_data[eterm][i][0] = src->_cal_data[eterm][m][0] * k0 + src->_cal_data[eterm][j][0] * k1;
					cal_data[eterm][i][1] = src->_cal_data[eterm][m][1] * k0 + src->_cal_data[eterm][j][1] * k1;
				  }
        	  }
          }
          else{
              float k0 = 1.0 - k1;
              for (eterm = 0; eterm < 5; eterm++) {
                cal_data[eterm][i][0] = src->_cal_data[eterm][j][0] * k0 + src->_cal_data[eterm][j+1][0] * k1;
                cal_data[eterm][i][1] = src->_cal_data[eterm][j][1] * k0 + src->_cal_data[eterm][j+1][1] * k1;
              }
          }

          break;

#else
          float k1 = (float)(f - src->_frequencies[j])
                          / (src->_frequencies[j+1] - src->_frequencies[j]);

          // avoid glitch between freqs in different harmonics mode
          if (IS_HARMONIC_MODE(src->_frequencies[j]) != IS_HARMONIC_MODE(src->_frequencies[j+1])) {
            // assume f[j] < f[j+1]
            k1 = IS_HARMONIC_MODE(f) ? 1.0 : 0.0;
          }

          float k0 = 1.0 - k1;
          for (eterm = 0; eterm < 5; eterm++) {
            cal_data[eterm][i][0] = src->_cal_data[eterm][j][0] * k0 + src->_cal_data[eterm][j+1][0] * k1;
            cal_data[eterm][i][1] = src->_cal_data[eterm][j][1] * k0 + src->_cal_data[eterm][j+1][1] * k1;
          }
          break;
#endif