Computes the quadratic joint time-frequency representation for the input signal. You can compute the short-time Fourier transform (STFT) spectrogram, the Gabor spectrogram, the adaptive spectrogram, the Wigner-Ville distribution, the Choi-Williams distribution, and the cone-shaped distribution.


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Dialog Box Options

Inputs/Outputs

  • ci32.png Start —

    Specifies the start index, in samples, of the processed part of Signal.

  • cmsdt.png Signal —

    Specifies the block diagram terminal of the signal you want to load. This input is available only if you select the From terminal option in the Data Source section.

  • cmsdt.png Waveform —

    is the input signal.

  • c1ddbl.png Real Signal —

    Specifies the input signal. The signal can be a waveform, a real array, or a complex array.

  • cpath.png File path —

    Specifies the file path of the data you want to load. This input is available only when you select the From file option in the Data Source section.

  • c1dcdb.png Complex Signal —

    Specifies the input signal. The signal can be a waveform, a real array, or a complex array.

  • cerrcodeclst.png error in (no error) —

    error in describes error conditions that occur before this node runs. This input provides standard error in functionality.

  • ierrcodeclst.png error out —

    error out contains error information. This output provides standard error out functionality.

  • ii32.png Length —

    Returns the actual length of the processed signal.

  • ifxdt.png Scale Info —

    Returns the time scale and the frequency scale information of the time-frequency representation. Use the TFA Get Time and Freq Scale Info VI to return detailed information about the time scale and the frequency scale.

  • i2ddbl.png Spectrogram —

    Returns the quadratic time-frequency representation of the signal. Each row corresponds to the instantaneous power spectrum at a certain time.

  • ibool.png dB —

    Specifies whether this Express VI displays the spectrogram in decibels.

    • Examples

    Refer to the following VIs for examples of using the Time Frequency Spectrogram VI:

    • The Need for JTFA VI: labview\examples\Time Frequency Analysis\TFAGettingStarted
    • Quadratic JTFA Method VI: labview\examples\Time Frequency Analysis\TFAGettingStarted
    • Heart Sound TFA VI: labview\examples\Time Frequency Analysis\TFAApplications
    • Cross Term VI: labview\examples\Time Frequency Analysis\TFAGettingStarted