Documentation

### This is machine translation

Translated by
Mouseover text to see original. Click the button below to return to the English version of the page.

# normalize

Normalize filter numerator or feed-forward coefficients

## Syntax

```normalize(hq) g = normalize(hd) ```

## Description

`normalize(hq)` normalizes the filter numerator coefficients for a quantized filter to have values between -1 and 1. The coefficients of `hq` change — `normalize` does not copy `hq` and return the copy. To restore the coefficients of `hq` to the original values, use `denormalize`.

Note that for lattice filters, the feed-forward coefficients stored in the property `lattice` are normalized.

`g = normalize(hd)` normalizes the numerator coefficients for the filter `hq` to between -1 and 1 and returns the gain `g` due to the normalization operation. Calling `normalize` again does not change the coefficients. `g` always returns the gain returned by the first call to normalize the filter.

## Examples

collapse all

Create a direct form II quantized filter that uses second-order sections. Then use normalize to maximize the use of the range of representable coefficients.

```d = fdesign.lowpass('n,fp,ap,ast',8,.5,2,40); hd = design(d,'ellip'); hd.arithmetic ='fixed';```

Check the filter coefficients. Note that InitialSOSMatrix(3,2)>1

`InitialSOSMatrix = hd.sosMatrix;`

Use normalize to modify the coefficients into the range between -1 and 1. The output g contains the gains applied to each section of the SOS filter.

`g = normalize(hd);`

None of the numerator coefficients exceed -1 or 1.