Skip to main content

Release notes

Download releases from the signal-processing-ignition releases page.

0.1.0​

Released 19 October 2026. The first release.

Ignition support: 8.1.33 or newer in the 8.1 line, and 8.3.3 or newer in the 8.3 line.

33 scipy.signal functions under system.signal, with SciPy 1.18.1's names, parameters, defaults and results, in every scope.

Added​

  • Detrending and windows: detrend, get_window (every window except dpss, with the _symmetric and _periodic suffixes).
  • Filter design: butter, cheby1, cheby2, ellip, bessel (every band type, 'ba', 'zpk' and 'sos' output, analog designs, fs); order selection buttord, cheb1ord, cheb2ord, ellipord; responses freqz, freqz_sos and its older name sosfreqz. Zeros, poles and responses are Python complex numbers.
  • Filtering: lfilter, lfilter_zi, sosfilt, sosfilt_zi, filtfilt, sosfiltfilt.
  • Smoothing: savgol_coeffs, savgol_filter (all five edge modes, derivatives), medfilt.
  • Peaks: find_peaks (height, threshold, distance, prominence, width, plateau size), peak_prominences, peak_widths.
  • Spectra: welch, periodogram, spectrogram (modes psd, complex, magnitude, angle, phase), hilbert.
  • Resampling: resample, resample_poly (every padtype), decimate.
  • Tests: random comparison with SciPy, property checks, invalid-call checks, an accuracy test run inside Ignition and a gateway-scope spot check.

Differences from SciPy​

See Differences from SciPy for the full list.

  • Lists and tuples are interchangeable; signals are 1-D; None, NaN and infinity in the data raise ValueError.
  • Where SciPy needs a numpy array, lists work: windows given as values, prominence_data, and welch and spectrogram input (SciPy 1.18.1 fails on plain lists there).
  • Savitzky-Golay least squares are solved exactly, so coefficients stay correct at high orders where SciPy's lose accuracy.
  • Equal-height peaks competing under distance are ranked by position, the later first (SciPy's choice depends on the CPU).
  • resample_poly with padtype 'reflect' or 'antireflect' on one sample raises ValueError (SciPy crashes the Python process).
  • Not supported: dpss windows, freqz's plot, filtfilt's method='gust', detrend functions passed as callables, dlti systems in decimate. Integer arguments (orders, lengths, factors) must be integers.