TFA Fast Mean Instantaneous Frequency VI

LabVIEW 2014 Advanced Signal Processing Toolkit Help

Edition Date: June 2014

Part Number: 372656C-01

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Owning Palette: Feature Extraction VIs

Requires: Advanced Signal Processing Toolkit

Uses the Gabor expansion-based method to compute the mean instantaneous frequency (MIF) for signal. Wire data to the signal input to determine the polymorphic instance to use or manually select the instance.

Use the pull-down menu to select an instance of this VI.

TFA Fast Mean Instantaneous Frequency (Waveform)

order specifies how this VI balances the bias and the variance of the MIF estimation. order must be greater than or equal to 0, or this VI sets order to 0 automatically. The default is 2. A higher order results in a large variance but less bias.
signal specifies the input signal.
time interval specifies the time interval, in samples, to observe the MIF of the signal. The default is –1, which specifies that this VI adjusts time interval automatically so that no more than 512 time bins exist in MIF.
Gaussian window length specifies the length of the Gaussian window, in samples, of the Gabor elementary functions and controls the relationship between the time resolution and the frequency resolution of the spectrogram. Gaussian window length must be a power of 2 and greater than or equal to 8. As the value of Gaussian window length increases, the frequency resolution increases, but the time resolution decreases. Gaussian window length determines the other parameters of the Gabor elementary functions. The number of frequencies of Gabor elementary functions, or N (frequency bins), of Gabor elementary functions is half of Gaussian window length. The oversampling rate is 4, that is, the dM (time steps) of the Gabor elementary functions equals N (frequency bins)/4. The variance of the Gaussian envelope window equals dM (time steps)×N (frequency bins)/(2).
error in describes error conditions that occur before this node runs. This input provides standard error in functionality.
MIF returns the mean instantaneous frequency of the signal at each time bin.
t0 returns the lowest value of the time bins in seconds.
dt returns the interval between the time bins in seconds.
frequency returns the resulting mean instantaneous frequencies at each time bin in hertz.
error out contains error information. This output provides standard error out functionality.

TFA Fast Mean Instantaneous Frequency (Real)

order specifies how this VI balances the bias and the variance of the MIF estimation. order must be greater than or equal to 0, or this VI sets order to 0 automatically. The default is 2. A higher order results in a large variance but less bias.
signal specifies the input signal.
time interval specifies the time interval, in samples, to observe the MIF of the signal. The default is –1, which specifies that this VI adjusts time interval automatically so that no more than 512 time bins exist in MIF.
Gaussian window length specifies the length of the Gaussian window, in samples, of the Gabor elementary functions and controls the relationship between the time resolution and the frequency resolution of the spectrogram. Gaussian window length must be a power of 2 and greater than or equal to 8. As the value of Gaussian window length increases, the frequency resolution increases, but the time resolution decreases. Gaussian window length determines the other parameters of the Gabor elementary functions. The number of frequencies of Gabor elementary functions, or N (frequency bins), of Gabor elementary functions is half of Gaussian window length. The oversampling rate is 4, that is, the dM (time steps) of the Gabor elementary functions equals N (frequency bins)/4. The variance of the Gaussian envelope window equals dM (time steps)×N (frequency bins)/(2).
error in describes error conditions that occur before this node runs. This input provides standard error in functionality.
sampling rate specifies the sampling rate of signal in hertz. sampling rate must be greater than 0, or this VI sets sampling rate to 1 automatically. The default is 1.
MIF returns the mean instantaneous frequency of the signal at each time bin.
t0 returns the lowest value of the time bins in seconds.
dt returns the interval between the time bins in seconds.
frequency returns the resulting mean instantaneous frequencies at each time bin in hertz.
error out contains error information. This output provides standard error out functionality.

TFA Fast Mean Instantaneous Frequency (Complex)

order specifies how this VI balances the bias and the variance of the MIF estimation. order must be greater than or equal to 0, or this VI sets order to 0 automatically. The default is 2. A higher order results in a large variance but less bias.
signal specifies the input signal.
time interval specifies the time interval, in samples, to observe the MIF of the signal. The default is –1, which specifies that this VI adjusts time interval automatically so that no more than 512 time bins exist in MIF.
Gaussian window length specifies the length of the Gaussian window, in samples, of the Gabor elementary functions and controls the relationship between the time resolution and the frequency resolution of the spectrogram. Gaussian window length must be a power of 2 and greater than or equal to 8. As the value of Gaussian window length increases, the frequency resolution increases, but the time resolution decreases. Gaussian window length determines the other parameters of the Gabor elementary functions. The number of frequencies of Gabor elementary functions, or N (frequency bins), of Gabor elementary functions is half of Gaussian window length. The oversampling rate is 4, that is, the dM (time steps) of the Gabor elementary functions equals N (frequency bins)/4. The variance of the Gaussian envelope window equals dM (time steps)×N (frequency bins)/(2).
error in describes error conditions that occur before this node runs. This input provides standard error in functionality.
sampling rate specifies the sampling rate of signal in hertz. sampling rate must be greater than 0, or this VI sets sampling rate to 1 automatically. The default is 1.
MIF returns the mean instantaneous frequency of the signal at each time bin.
t0 returns the lowest value of the time bins in seconds.
dt returns the interval between the time bins in seconds.
frequency returns the resulting mean instantaneous frequencies at each time bin in hertz.
error out contains error information. This output provides standard error out functionality.

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