SPpcXec

Routine

void SPpcXec (const float pc[], float ec[], int Np)

Purpose

Convert predictor coefficients to prediction error filter coefficients

Description

  ec[0]  = 1
  ec[1]  = -pc[0]
        ...
  ec[Np] = -pc[Np-1]

Predictor coefficients are usually expressed algebraically as vectors with 1-offset indexing. The correspondence to the 0-offset C-arrays is as follows.

  p(1) <==> pc[0]       predictor coefficient corresponding to lag 1
  p(i) <==> pc[i-1]     1 <= i < Np

Parameters

-> const float pc[]

Vector of predictor coefficients (Np values). These are the coefficients of the predictor filter, with pc[0] being the predictor coefficient corresponding to lag 1, and pc[Np-1] corresponding to lag Np.

<- float ec[]

Prediction error (residual) filter coefficients (Np + 1 values)

-> int Np

Number of predictor coefficients (Np can be zero)

Author / revision