vDSP_biquadm_SetTargetsSingle

Declaration

void vDSP_biquadm_SetTargetsSingle(vDSP_biquadm_Setup __setup, const float *__targets, float __interp_rate, float __interp_threshold, vDSP_Length __start_sec, vDSP_Length __start_chn, vDSP_Length __nsec, vDSP_Length __nchn);

Parameters

• __setup:

  The filter state object whose coefficients the function updates.

• __targets:

  An input array of single-precision target values to the function applies to selected coefficients.

• __rate:

  The rate constant that determines the size of increments to the coefficient values. The rate’s value must be greater than zero, otherwise the function’s behavior is undefined.

• __threshold:

  The threshold constant that determines how close a coefficient’s value must be to the target value before incrementation stops. The threshold’s value must be greater than zero, otherwise the function’s behavior is undefined.

• __start_sec:

  The first section to update in each channel.

• __start_chn:

  The first channel to update.

• __nsec:

  The number of sections to update in each channel.

• __nchn:

  The number of channels to update.

Discussion

Provide the filter coefficient targets as single-precision values. The function increments each selected coefficient at each sample until the difference between its value and the target value is less than a specified threshold.

The last four parameters define which coefficients the function changes. The actual increment for each selected coefficient is a function of the rate constant and the difference between the target value and its initial value.

This function doesn’t allocate any additional memory.