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Owning Palette: Correlation and Spectral Analysis VIs

Installed With: Advanced Signal Processing Toolkit

Computes the single-sided complex cepstrum of an input univariate time series. This VI keeps the phase information of the input time series. You can reconstruct the original time series with the computed phase information and complex cepstrum. Wire data to the Xt input to determine the polymorphic instance to use or manually select the instance.

Details  Examples

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

Select an instance TSA Complex Cepstrum (waveform)TSA Complex Cepstrum (array)

TSA Complex Cepstrum (waveform)

	Xt specifies the input univariate time series.
	error in describes error conditions that occur before this VI or function runs. The default is no error. If an error occurred before this VI or function runs, the VI or function passes the error in value to error out. This VI or function runs normally only if no error occurred before this VI or function runs. If an error occurs while this VI or function runs, it runs normally and sets its own error status in error out. Use the Simple Error Handler or General Error Handler VIs to display the description of the error code. Use error in and error out to check errors and to specify execution order by wiring error out from one node to error in of the next node. status is TRUE (X) if an error occurred before this VI or function ran or FALSE (checkmark) to indicate a warning or that no error occurred before this VI or function ran. The default is FALSE. code is the error or warning code. The default is 0. If status is TRUE, code is a nonzero error code. If status is FALSE, code is 0 or a warning code. source specifies the origin of the error or warning and is, in most cases, the name of the VI or function that produced the error or warning. The default is an empty string.
	cepstrum returns the cepstrum information about Xt. t0 returns the lower boundary of the time range. dt returns the time increment. C(t) returns the resulting values of the complex cepstrum.
	phase info returns the phase information of Xt. DC specifies the phase information at zero frequency. Nyquist specifies the phase information at the Nyquist frequency.
	error out contains error information. If error in indicates that an error occurred before this VI or function ran, error out contains the same error information. Otherwise, it describes the error status that this VI or function produces. Right-click the error out front panel indicator and select Explain Error from the shortcut menu for more information about the error. status is TRUE (X) if an error occurred or FALSE (checkmark) to indicate a warning or that no error occurred. code is the error or warning code. If status is TRUE, code is a nonzero error code. If status is FALSE, code is 0 or a warning code. source describes the origin of the error or warning and is, in most cases, the name of the VI or function that produced the error or warning.

TSA Complex Cepstrum (array)

	sampling rate specifies the sampling rate, in hertz, of the input univariate time series Xt. The default is 1.
	Xt specifies the input univariate time series.
	error in describes error conditions that occur before this VI or function runs. The default is no error. If an error occurred before this VI or function runs, the VI or function passes the error in value to error out. This VI or function runs normally only if no error occurred before this VI or function runs. If an error occurs while this VI or function runs, it runs normally and sets its own error status in error out. Use the Simple Error Handler or General Error Handler VIs to display the description of the error code. Use error in and error out to check errors and to specify execution order by wiring error out from one node to error in of the next node. status is TRUE (X) if an error occurred before this VI or function ran or FALSE (checkmark) to indicate a warning or that no error occurred before this VI or function ran. The default is FALSE. code is the error or warning code. The default is 0. If status is TRUE, code is a nonzero error code. If status is FALSE, code is 0 or a warning code. source specifies the origin of the error or warning and is, in most cases, the name of the VI or function that produced the error or warning. The default is an empty string.
	cepstrum returns the cepstrum information about Xt. t0 returns the lower boundary of the time range. dt returns the time increment. C(t) returns the resulting values of the complex cepstrum.
	phase info returns the phase information of Xt. DC specifies the phase information at zero frequency. Nyquist specifies the phase information at the Nyquist frequency.
	error out contains error information. If error in indicates that an error occurred before this VI or function ran, error out contains the same error information. Otherwise, it describes the error status that this VI or function produces. Right-click the error out front panel indicator and select Explain Error from the shortcut menu for more information about the error. status is TRUE (X) if an error occurred or FALSE (checkmark) to indicate a warning or that no error occurred. code is the error or warning code. If status is TRUE, code is a nonzero error code. If status is FALSE, code is 0 or a warning code. source describes the origin of the error or warning and is, in most cases, the name of the VI or function that produced the error or warning.

TSA Complex Cepstrum Details

This VI computes the single-sided complex cepstrum C(t) of a univariate time series according to the following equation:

C(t) = FFT^–1{ln[FFT(X_t)]}

where X_t is the univariate time series and FFT(X_t) is a complex array. FFT(X_t) = P(f)e^jf(f).

In order to make the definition unique, this VI unwraps f(f) and removes the linear phase, so the computed cepstrum does not contain the phase information of the original time series. This VI saves the phase values of f(f) at frequency zero and frequency p into phase info. You can reconstruct the original time series using the phase values and the complex cepstrum.

Examples

Refer to the following VIs for examples of using the TSA Complex Cepstrum VI:

• Echo Canceling VI: labview\examples\Time Series Analysis\TSAApplications.llb
• Cepstrum Analysis VI: labview\examples\Time Series Analysis\TSAGettingStarted.llb