Applies a scaled window to the input sequence X. Wire data to the X input to determine the polymorphic instance to use or manually select the instance.


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Inputs/Outputs

  • c1ddbl.png X —

    X is a real vector.

  • cu32.png window —

    window is the window to apply to X.

    0Rectangle (default)
    1Hanning
    2Hamming
    3Blackman-Harris
    4Exact Blackman
    5Blackman
    6Flat Top
    74 Term B-Harris
    87 Term B-Harris
    9Low Sidelobe
    11Blackman Nuttall
    30Triangle
    31Bartlett-Hanning
    32Bohman
    33Parzen
    34Welch
    60Kaiser
    61Dolph-Chebyshev
    62Gaussian
  • cdbl.png window parameter —

    window parameter specifies the beta parameter for a Kaiser window, the standard deviation for a Gaussian window, and the ratio, s, of the main lobe to the side lobe for a Dolph-Chebyshev window. If window is any other window, this VI ignores this input.

    The default value of window parameter is NaN, which sets beta to 0 for a Kaiser window, the standard deviation to 0.2 for a Gaussian window, and s to 60 for a Dolph-Chebyshev window.

  • i1ddbl.png Windowed X —

    Windowed X is the input signal with the window applied.

  • inclst.png window properties —

    window properties returns the coherent gain and equivalent noise bandwidth of the window.

  • idbl.png eq noise BW —

    eq noise BW returns the equivalent noise bandwidth of the window. You can use eq noise BW to divide a sum of individual power spectra or to compute the power in a given frequency span.

  • idbl.png coherent gain —

    coherent gain returns the inverse of the scaling factor this VI applies to the window.

  • ii32.png error —

    error returns any error or warning from the VI. You can wire error to the Error Cluster From Error Code VI to convert the error code or warning into an error cluster.

    • The Scaled Time Domain Window VI scales the result so that when the power or amplitude spectrum of the windowed waveform is computed, all windows provide the same level within the accuracy constraints of the window. The Scaled Time Domain Window VI also returns important window properties for the selected window. These properties are useful when you use VIs that perform computations on the power spectrum, such as the Power & Frequency Estimate VI and the Spectrum Unit Conversion VI.

    If y represents the output sequence Windowed X, the Scaled Time Domain Window VI obtains the elements of y from:

    for i = 0, 1, 2, …

    where wi and cg are the coefficients and coherent gain of the window without scaling, respectively.

    This VI also returns the coherent gain (CG) and equivalent noise bandwidth (ENBW) of the selected window. For cosine windows, these two properties are constants, as listed in the following table.

    Window TypeCGENBW
    Rectangle1.01.0
    Hanning0.51.5
    Hamming0.541.362826
    Blackman-Harris0.423231.708538
    Exact Blackman0.426590713671.693699
    Blackman0.421.726757
    Flat Top0.2155789483.770246506303
    4 Term B-Harris0.358752.004353
    7 Term B-Harris0.271051400693424152.631905
    Low Sidelobe0.3232152182.215350782519
    Blackman Nuttall0.36358191.9761117

    If X is an empty input array and the selected window is a cosine window, this VI returns the window properties. If X is an empty input array and the selected window is not a cosine window, this VI sets the window properties to NaN and returns an error. For Triangle, Kaiser, Dolph-Chebyshev, and Gaussian windows, the window properties depend on the window length and the window parameters.