IIR_RATIOVER
IIR_RATIOVER, IIR_INV_COEF, IIR_INV_COEF, IIR_INV_COEF,
IIR_RATIOVER, IIR_RATIOVER, IIR_INV_COEF, IIR_INV_COEF,
} else if (k == IIR_RATIOVER) {