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Reference guides are available for functions and commands supported by OML, Tcl, and Python.
Reference Guide for OpenMatrix Language Functions
The Reference Guide contains documentation for all functions supported in the OpenMatrix language.
Signal Processing Commands
ifftn
N dimensional inverse fast Fourier transform.

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Reference guides are available for functions and commands supported by OML, Tcl, and Python.
- Scripting Guide for OpenMatrix Language
  OpenMatrix is a mathematical scripting language.
- Reference Guide for OpenMatrix Language Functions
  The Reference Guide contains documentation for all functions supported in the OpenMatrix language.
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  - Signal Processing Commands
    - barthannwin
      Bartlett-Hann window.
    - bessel3ap
      Create a normalized Bessel analog lowpass prototype filter in zero-pole-gain form.
    - besselap
      Create a normalized Bessel analog lowpass prototype filter in zero-pole-gain form.
    - besself
      Create a Bessel filter.
    - besself3
      Create a Bessel filter.
    - blackman
      Blackman window.
    - buttap
      Create a normalized Butterworth analog lowpass prototype filter in zero-pole-gain form.
    - butter
      Create a Butterworth filter.
    - buttord
      Design a Butterworth filter.
    - cheb1ap
      Create a normalized Chebyshev I analog lowpass prototype filter in zero-pole-gain form.
    - cheb2ap
      Create a normalized Chebyshev II analog lowpass prototype filter in zero-pole-gain form.
    - cheb1ord
      Design a Chebyshev I filter.
    - cheb2ord
      Design a Chebyshev II filter.
    - chebwin
      Dolph-Chebyshev window.
    - cheby1
      Create a Chebyshev I filter.
    - cheby2
      Create a Chebyshev II filter.
    - chirp
      Generate a chirp signal.
    - cmorwavf
      Generate a complex Morlet wavelet.
    - cpsd
      Compute cross power spectral density.
    - downsample
      Downsample a signal.
    - dba
      Acoustic A-weighting function.
    - dbb
      Acoustic B-weighting function.
    - dbc
      Acoustic C-weighting function.
    - dbu
      Acoustic U-weighting function.
    - diric
      Generate the Dirichlet function.
    - ellip
      Create an Elliptic filter.
    - ellipap
      Create a normalized Elliptic analog lowpass prototype filter in zero-pole-gain form.
    - ellipord
      Design an Elliptic filter.
    - fft
      Fast Fourier Transform.
    - fft2
      Two Dimensional Fast Fourier Transform.
    - fftn
      N dimensional fast Fourier transform (FFT).
    - fftshift
      Shift frequency spectrum related vectors to center the dc element
    - filter
      Filter a signal with an IIR or FIR filter.
    - filter2
      Perform 2D FIR filtering.
    - filtfilt
      Filter a signal forward and then backward, compensating for end effects.
    - filtic
      Determine the initial state condition of an IIR filter, given the input and output signal histories.
    - findpeaks
      Locate the peaks of a signal.
    - fir1
      Create a digital FIR filter.
    - firls
      Create a digital FIR multi-band filter with a least squares fitting.
    - fold
      Create one-sided spectrum amplitude vectors from the two-sided equivalents.
    - freq
      Generate a vector of frequency locations.
    - freqs
      Compute analog filter frequency response values.
    - freqz
      Compute digital filter frequency response values.
    - gauspuls
      Generate a sampled Gaussian modulated sinusoidal pulse centered at zero, with a specified center frequency and fractional bandwidth.
    - gmonopuls
      Generate a sampled Gaussian monopulse.
    - grpdelay
      Compute digital filter group delay values.
    - hamming
      Hamming window.
    - hann
      Hann window.
    - hilbert
      Hilbert transform.
    - ifft
      Inverse Fast Fourier transform.
    - ifft2
      Two-dimensional inverse fast Fourier transform.
    - ifftn
      N dimensional inverse fast Fourier transform.
    - ifftshift
      Shift frequency spectrum related vectors to uncenter the dc element to the first position.
    - impz
      Compute the impulse response of a digital filter.
    - invfreqs
      Compute analog filter coefficients from frequency response values.
    - invfreqz
      Compute digital filter coefficients from frequency response values.
    - istft
      Inverse Short-Time Fourier Transform.
    - kaiser
      Kaiser-Bessel window.
    - medfilt1
      Applies a moving median filter in one dimension.
    - mexihat
      Generate a Mexican hat wavelet.
    - meyeraux
      Generate a Meyer auxiliary wavelet.
    - mscohere
      Estimates the mean squared coherence of time domain signals.
    - morlet
      Generate a Morlet wavelet.
    - parzenwin
      Parzen window.
    - peak2peak
      Compute signal maximum to minimum differences.
    - peak2rms
      Compute signal peak to rms ratios.
    - pulstran
      Generate a pulse train, with the pulse defined either by a function or a sampled pulse.
    - pwelch
      Computes the power spectral density.
    - rectpuls
      Generate a sampled rectangular pulse centered at zero, with a specified width.
    - resample
      Resample a real signal by a rational factor using a polyphase FIR filter.
    - rssq
      Compute root sum squared values.
    - sawtooth
      Generate a sawtooth wave with range [-1,1] and period 2*pi.
    - shanwavf
      Generate a complex Shannon wavelet.
    - shiftdata
      Transfer a designated matrix dimension to the lead position.
    - sosfilt
      Filter a real signal with a second order section IIR filter.
    - square
      Generate a square wave with range [-1,1] and period 2*pi.
    - sinc
      Compute the sinc function.
    - stft
      Short-Time Fourier Transform.
    - spectrogram
      Spectrogram.
    - stairs
      Generate a stair step plot.
    - tfestimate
      Estimates the transfer function from time domain signals.
    - tripuls
      Generate a sampled triangular pulse centered at zero, with a specified width and skew.
    - udecode
      Convert quantized integer matrix elements to floating-point values.
    - uencode
      Quantize real matrix elements to integer values.
    - unshiftdata
      Revert the order of matrix dimensions modified by shiftdata.
    - unwrap
      Unwrap a vector of phase angles.
    - upsample
      Upsample a signal.
    - welchwin
      Welch window.
    - xcorr
      Cross correlation, computed over a range of lags.
    - xcov
      Cross covariance, computed over a range of lags.
    - zplane
      Plot zeros and poles of a discrete transfer function.
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- Python in Compose Reference Guide
Appendix
Get help for the optional libraries that are available in the Extension Manager.
Frequently Asked Questions
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ifftn

N dimensional inverse fast Fourier transform.

Syntax

x = ifftn(f)

Inputs

f: The frequency spectrum to be transformed into the time domain.; Type: double; Dimension: vector | matrix

Outputs

x: The time domain representation of f.

Comments

ifftn uses the FFTW library.