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    Generates the set of filter coefficients you need to implement an FIR windowed filter.

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    filter type

    The passband of the filter.

    Lowpass

    Uses a lowpass filter.

    Highpass

    Uses a highpass filter.

    Bandpass

    Uses a bandpass filter.

    Bandstop

    Uses a bandstop filter.

    Default: Lowpass

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    sampling frequency

    The sampling frequency in Hz.

    If this input is less than or equal to 0, the node returns an empty array as well as an error.

    Default: 1.0 Hz

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    taps

    The total number of FIR coefficients.

    If taps is less than or equal to 0, the node returns an empty array as well as an error.

    If filter type is 1 (Highpass) or 3(Bandstop), this input must be odd.

    Default: 25

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    window

    The type of smoothing window . Smoothing windows decrease ripple in the filter passband and improve the ability of the filter to attenuate frequency components in the filter stopband.

    Rectangle 0 Specifies a rectangle window.
    Hanning 1 Specifies a Hanning window.
    Hamming 2 Specifies a Hamming window.
    Blackman-Harris 3 Specifies a Blackman-Harris window.
    Exact Blackman 4 Specifies an Exact Blackman window.
    Blackman 5 Specifies a Blackman window.
    Flat Top 6 Specifies a Flat Top window.
    4 Term B-Harris 7 Specifies a 4 Term B-Harris window.
    7 Term B-Harris 8 Specifies a 7 Term B-Harris window.
    Low Sidelobe 9 Specifies a Low Sidelobe window.
    Blackman Nuttall 11 Specifies a Blackman Nuttall window.
    Triangle 30 Specifies a Triangle window.
    Bartlett-Hanning 31 Specifies a Bartlett-Hanning window.
    Bohman 32 Specifies a Bohman window.
    Parzen 33 Specifies a Parzen window.
    Welch 34 Specifies a Welch window.
    Kaiser 60 Specifies a Kaiser window.
    Dolph-Chebyshev 61 Specifies a Dolph-Chebyshev window.
    Gaussian 62 Specifies a Gaussian window.

    Default: 0—Rectangle

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    option

    An enum value that determines whether to scale the FIR windowed coefficients.

    not scaled

    Does not scale the FIR windowed coefficients.

    scaled

    Scales the FIR windowed coefficients.

    Default: not scaled

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    low cutoff frequency

    The low cutoff frequency in Hz. If this input is less than or equal to zero or does not meet the Nyquist criterion, the node returns an empty array as well as an error.

    Default: 0.125

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    high cutoff frequency

    The high cutoff frequency, in Hz.

    The node places the following restrictions on this parameter according to filter type:

    filter type Restrictions
    0 (Lowpass) or 1 (Highpass) The node ignores this input.
    2 (Bandpass) or 3 (Bandstop) This value must be greater than low cutoff frequency and less than half of sampling frequency. It must also observe the Nyquist criterion.

    Default: 0.45

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    window parameter

    A value that affects the output coefficients when you specify window to be Kaiser, Gaussian, and Dolph-Chebyshev. If window is any other type of window, this node ignores this input.

    This input represents the following information for each type of window:

    • Kaiser—Beta parameter
    • Gaussian—Standard deviation
    • Dolph-Chebyshev—The ratio, s, of the main lobe to the side lobe

    Default: NaN—0 for a Kaiser window, 0.2 for a Gaussian window, and 60 for a Doph-Chebyshev window

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    FIR windowed coefficients

    Filter coefficients.

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    error

    A value that represents any error or warning that occurs when this node executes.