normalize

Normalize filter numerator or feed-forward coefficients

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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

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Open Live Script

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.

Version History

Introduced in R2011a