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Computes the signal energy distribution in the joint time-frequency domain, using the short-time Fourier transform (STFT) algorithm.

## x

Input time-domain signal.

## time-freq sampling info

Density to use to sample the signal in the joint time-frequency domain and defines the size of the resulting 2D time-frequency array.

### time steps

Number of samples to shift the sliding window. When time steps is less than or equal to zero, this node adjusts time steps automatically so that no more than 512 rows exist in STFT spectrogram {x}.

Default: -1

### frequency bins

FFT size of the STFT. If frequency bins is less than or equal to zero, this node sets frequency bins to 512. If frequency bins is 1, this node coerces frequency bins to 2.

Default: 512

## window info

Information about the window you want to use to compute the STFT.

### type

Type of window to use to compute the STFT.

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

Default: Hanning

### length

Length of the window in samples. If length is less than or equal to zero, this node sets length to 64.

Default: 64

## window parameter

The beta parameter for a Kaiser window; the ratio, s, of the mainlobe to the sidelobe for a Dolph-Chebyshev window; and the standard deviation for a Gaussian window. If the window type is any other window, this node ignores this input. The default value of window parameter is NaN, which sets beta to 0 for a Kaiser window, s to 60 for a Dolph-Chebyshev window, and the standard deviation to for a Gaussian window, where L is the window length.

## energy conservation?

A Boolean that determines whether to scale STFT spectrogram {x} so that the energy in the joint time-frequency domain equals the energy in the time domain.

 TRUE Scales STFT spectrogram {x} so that the energy in the joint time-frequency domain equals the energy in the time domain. FALSE Does not scale STFT spectrogram {x} so that the energy in the joint time-frequency domain equals the energy in the time domain.

Default: TRUE

## time-freq config

Configuration of the frequency bins. time-freq config also determines the number of columns in STFT spectrogram {x}.

### force freq bins to power of 2?

Whether to coerce the frequency bins to a power of 2. If force freq bins to power of 2? is TRUE and frequency bins is not a power of 2, this node sets frequency bins to the nearest power of 2.

 TRUE Coerces the frequency bins to a power of 2. FALSE Does not coerce the frequency bins to a power of 2.

Default: TRUE

### exclude Nyquist frequency?

Whether to exclude the energy at the Nyquist frequency from STFT spectrogram {x}. If frequency bins is even and exclude Nyquist frequency? is TRUE, STFT spectrogram {x} does not include the energy at the Nyquist frequency. If frequency bins is odd, LabVIEW ignores exclude Nyquist frequency?.

Default: TRUE

## STFT spectrogram {x}

A 2D array that describes the time waveform energy distribution in the joint time-frequency domain.

## error

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