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filterAnalysisOptions

Filter analysis options

Since R2024a

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Description

filterAnalysisOptions specifies analysis options for filters displayed in Filter Analyzer.

Creation

Syntax

opts = filterAnalysisOptions
opts = filterAnalysisOptions(analysis)
opts = filterAnalysisOptions(analysis,overlay)
opts = filterAnalysisOptions(___,Name=Value)

Description

opts = filterAnalysisOptions returns an object containing magnitude-response analysis options. Use opts to specify analysis options for the Filter Analyzer app.

opts = filterAnalysisOptions(analysis) returns filter analysis options for the specified analysis type. analysis sets the Analysis property.

example

opts = filterAnalysisOptions(analysis,overlay) returns filter analysis options for the specified analysis and overlay analysis types. overlay sets the OverlayAnalysis property.

opts = filterAnalysisOptions(___,Name=Value) specifies Properties using one or more name-value arguments, in addition to any combination of input arguments from previous syntaxes.

Input Arguments

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Analysis type, specified as one of these options:

  • Frequency-domain analyses:

    • "magnitude" — Magnitude response

    • "phase" — Phase response

    • "groupdelay" — Group delay response

    • "phasedelay" — Phase delay response

    • "magestimate" — Magnitude response estimate

    • "noisepsd" — Noise power spectral density (PSD)

  • Time-domain analyses:

    • "impulse" — Impulse response

    • "step" — Step response

  • Other analyses:

    • "polezero" — Pole-zero plot

    • "info" — Filter information

    • "coefficients" — Filter coefficients

You can also specify analysis as a name-value argument: filterAnalysisOptions(Analysis=analysis) is equivalent to filterAnalysisOptions(analysis).

For more information, see Analysis.

Overlaid analysis, specified as a string.

  • If you set analysis to a frequency-domain analysis, then overlay must be also a frequency-domain analysis.

  • If you set analysis to a time-domain analysis, then overlay must be also a time-domain analysis.

  • analysis and overlay must be set to different values.

  • This argument is not supported if you set analysis to "polezero", "info", or "coefficients".

You can also specify overlay as a name-value argument: filterAnalysisOptions(Analysis=analysis,OverlayAnalysis=overlay) is equivalent to filterAnalysisOptions(analysis,overlay)

Properties

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Analysis Type

Analysis type, specified as one of these options:

  • Frequency-domain analyses:

    • "magnitude" — Magnitude response

    • "phase" — Phase response

    • "groupdelay" — Group delay response

    • "phasedelay" — Phase delay response

    • "magestimate" — Magnitude response estimate

    • "noisepsd" — Noise power spectral density (PSD)

  • Time-domain analyses:

    • "impulse" — Impulse response

    • "step" — Step response

  • Other analyses:

    • "polezero" — Pole-zero plot

    • "info" — Filter information

    • "coefficients" — Filter coefficients

For more information, see Analysis on the Filter Analyzer page.

Overlaid analysis, specified as a string scalar or character vector.

  • If you set Analysis to a frequency-domain analysis, then OverlayAnalysis must be also a frequency-domain analysis.

  • If you set Analysis to a time-domain analysis, then OverlayAnalysis must be also a time-domain analysis.

  • Analysis and OverlayAnalysis must be set to different values.

  • This argument is not supported if you set Analysis to "polezero", "info", or "coefficients".

For more information, see Analysis on the Filter Analyzer page.

Frequency Normalization and Sample Rate

Frequency normalization mode, specified as one of these options:

  • "normalized" — The app normalizes the response of each input filter with respect to its sample rate and computes responses using normalized frequencies expressed in rad/sample.

  • "unnormalized" — The app computes responses in cyclical frequencies expressed in hertz. For filters with no sample rate, the app assumes a rate of 1 Hz.

  • "auto" — The app uses the "unnormalized" mode if all filters under analysis have a specified sample rate and the "normalized" mode otherwise.

Data Types: char | string

Reference sample rate selection mode, specified as one of these options:

  • "max" — The app uses the maximum sample rate of all the filters under analysis in a display.

  • "specify" — Specify a sample rate value using the ReferenceSampleRate property.

This property does not apply if you set FrequencyNormalizationMode to "normalized".

Data Types: char | string

Reference sample rate, specified as a positive scalar. The app uses the specified reference sample rate to normalize filter responses and to define the overall Nyquist range over which to analyze the filters. This property applies only if you set ReferenceSampleRateMode to "specify".

Example: 44.1e3

Data Types: double

Frequency-Domain Analysis

Analysis frequency range, specified as one of these options:

  • "onesided" — The app computes responses over the range [0, π) when using normalized frequencies and over the range [0, referenceSampleRate/2) when using unnormalized frequencies.

  • "twosided" — The app computes responses over the range [0, 2π) when using normalized frequencies and over the range [0, referenceSampleRate) when using unnormalized frequencies.

  • "centered" — The app computes responses over the range [–π, π) when using normalized frequencies and over the range [–referenceSampleRate/2, referenceSampleRate/2) when using unnormalized frequencies. This option does not apply when you set FrequencyScale to "log".

  • "freqvector" — The app computes responses at the frequency points specified using FrequencyVector.

  • "auto" — The app computes one-sided responses if all filters under analysis in a display have real-valued coefficients and two-sided responses if at least one filter has complex-valued coefficients.

Data Types: char | string

Number of discrete Fourier transform points used to compute filter responses, specified as a positive integer. This property does not apply when you set FrequencyRange to "freqvector".

Example: 1024

Data Types: double

Frequency scale for visualizing filter responses, specified as "linear" for a linear frequency scale or "log" for a logarithmic frequency scale. The "log" option does not apply if you set FrequencyRange to "centered".

Data Types: char | string

Frequency vector over which to compute filters, specified as a vector of finite real values. If you set FrequencyVectorUnits to "normalized", the analyzer assumes the vector is in units of rad/sample. Otherwise, it assumes the vector in the selected units.

This property applies only when you set FrequencyRange to "freqvector". This property is not supported when you set either Analysis or OverlayAnalysis to "magestimate" or "noisepsd".

Example: [-pi/3 0 pi/6 pi/2] and [-200 0 100 300] are equivalent when the sample rate is 600 Hz.

Data Types: double

Units for frequency vector values, specified as "normalized", "Hz", "kHz", "MHz", or "GHz". If you set this property to "normalized", the analyzer assumes the frequency vector is normalized in units of rad/sample. Otherwise, it assumes the vector is in the selected units.

This property applies only when you set FrequencyRange to "freqvector". This property is not supported when you set either Analysis or OverlayAnalysis to "magestimate" or "noisepsd".

Data Types: char | string

Magnitude Response and Magnitude Estimate

Magnitude response mode, specified as one of these options:

  • "linear" — The app computes the filter response as the absolute value of the frequency response.

  • "squared" — The app computes the filter response as the magnitude squared of the frequency response.

  • "db" — The app computes the filter response as the magnitude, in decibel scale, of the frequency response.

  • "zerophase" — The app computes the filter response as the zero-phase response. This option does not apply if you set either Analysis or OverlayAnalysis to "magestimate".

Data Types: char | string

Number of trials to compute the frequency response estimate, specified as a positive integer. This property applies only when you set either Analysis or OverlayAnalysis to "magestimate".

Example: 24

Data Types: double

Magnitude response normalization, specified as a logical 0 (false) or 1 (true). If you set this property to true, the analyzer normalizes the filter magnitude response to 1.

Data Types: logical

Phase Response and Phase Delay Response

Units for the phase response or phase delay response, specified as "radians" or "degrees".

Data Types: char | string

Option to use continuous phase when computing phase response, specified as a logical 0 (false) or 1 (true).

Data Types: logical

Group Delay Response

Units for the group delay response, specified as "samples" or "time".

Data Types: char | string

Noise PSD

Number of trials to compute the noise power spectral density, specified as a positive integer.

Example: 10

Data Types: double

Time-Domain Analysis

Response length mode, specified as one of these options:

  • "auto" — The app uses the impzlength function to estimate the response length.

  • "specify" — You set the response length using the ResponseLength property.

Data Types: char | string

Length of the time-domain response, specified as a positive integer. This property applies only if you set ResponseLengthMode to "specify".

Example: 128

Data Types: double

Coefficients

Format for the filter coefficients, specified as "decimal", "hex", or "binary".

Data Types: char | string

All Domains

Double-precision reference filter display, specified as a logical 0 (false) or 1 (true). If you set this property to true, Filter Analyzer displays the responses of quantized filters and their double-precision references.

Data Types: logical

View of the polyphase decomposition of the polyphase filter, specified as a logical 0 (false) or 1 (true).

Data Types: logical

Cascaded transfer function computation mode, specified as one of these options:

  • "complete" — The app computes the overall response of the cascaded sections.

  • "individual" — The app computes the response of each section.

  • "cumulative" — The app computes cumulative responses.

  • "specify" — You use the CTFAnalysisSections property to specify the combination of sections over which to compute responses.

Data Types: char | string

Section combinations for cascaded transfer function (CTF) response computation, specified as a cell array. This property applies only when you set CTFAnalysisMode to "specify".

Example: {[1 2 3],[4 5 6]} directs the app to compute responses for a cascade of sections 1, 2, and 3 and a cascade of sections 4, 5, and 6.

Data Types: cell

Examples

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Open Live Script

Design a lowpass FIR filter and display its phase response in Filter Analyzer. Use 1024 NFFT points, and display the phase in degrees.

d = designfilt("lowpassfir", ...
    PassbandFrequency=0.45,StopbandFrequency=0.55, ...
    PassbandRipple=1,StopbandAttenuation=60);
opts = filterAnalysisOptions("phase")
opts = 
  filterAnalysisOptions with properties:

                      Analysis: "phase"
               OverlayAnalysis: "none"
    FrequencyNormalizationMode: "auto"
       ReferenceSampleRateMode: "max"
                FrequencyRange: "auto"
                          NFFT: 8192
                FrequencyScale: "linear"
                    PhaseUnits: "radians"
               ContinuousPhase: 0
               ReferenceFilter: 1
        PolyphaseDecomposition: 0
               CTFAnalysisMode: "complete"


opts.NFFT = 1024;
opts.PhaseUnits = "degrees";
filterAnalyzer(d,AnalysisOptions=opts)

Version History

Introduced in R2024a

See Also

Apps

Objects

Functions