getQualityFactor

Get quality factor

Syntax

Q = getQualityFactor(npFilter)

Description

Q = getQualityFactor(npFilter) returns the quality factor (Q factor) of the notch peak filter. The Q factor is defined as the center frequency divided by the bandwidth.

Examples

Compute Quality Factor of Notch Peak Filter

Create a dsp.NotchPeakFilter object in the default configuration, where the Specification property is set to 'Bandwidth and center frequency'.

np = dsp.NotchPeakFilter

np = 
  dsp.NotchPeakFilter with properties:

          Specification: 'Bandwidth and center frequency'
              Bandwidth: 2205
        CenterFrequency: 11025
    NormalizedFrequency: false
             SampleRate: 44100

Determine the quality factor of the filter using the getQualityFactor function. The quality factor is given by the ratio of the center frequency to the bandwidth.

getQualityFactor(np)

ans = 
5

Visualize the filter response using filterAnalyzer.

filterAnalyzer(np)

Input Arguments

npFilter — Notch peak filter

dsp.NotchPeakFilter

Notch peak filter whose quality factor is computed, specified as a dsp.NotchPeakFilter object.

Output Arguments

Q — Quality factor

scalar

Quality factor of the filter, returned as a scalar. The Q factor is defined as the center frequency divided by the bandwidth.

Data Types: double

Version History

Introduced in R2014a

R2024a: Support for normalized frequencies

In the dsp.NotchPeakFilter object, you can now specify the 3-dB bandwidth and center frequency values in normalized frequency units (0 to 1). To enable this functionality, set the NormalizedFrequency property of the object to true.