IIR digital filters (C API)

typedef struct _EmlIIR EmlIIR

Filter definition and state.

IIR filters using cascades of Second Order Sections (SOS) Follows conventions of scipy.signal.sosfilt

A single second-order filter is just a special case with n_stages=1

EmlError eml_iir_check(EmlIIR filter)

Check that filter is correctly initialized.


filter – Filter instance


EmlOk on success, or error on failure

float eml_iir_filter(EmlIIR filter, float in)

Run filter to comput new values.

Modifies state internally. NOTE: no error checking is performed. See eml_iir_check() for that

  • filter – Filter instance

  • in – Input value


Filtered value