Array API Standard Support: signal#

This page explains some caveats of the signal module and provides (currently incomplete) tables about the CPU, GPU and JIT support.

Caveats#

JAX and CuPy provide alternative implementations for some signal functions. When such a function is called, a decorator decides which implementation to use by inspecting the xp parameter.

Hence, there can be, especially during CI testing, discrepancies in behavior between the default NumPy-based implementation and the JAX and CuPy backends. Skipping the incompatible backends in unit tests, as described in the Adding tests section, is the currently recommended workaround.

The functions are decorated by the code in file scipy/signal/_support_alternative_backends.py:

  1import functools
  2import types
  3from scipy._lib._array_api import (
  4    is_cupy, is_jax, scipy_namespace_for, SCIPY_ARRAY_API, xp_capabilities
  5)
  6
  7from ._signal_api import *   # noqa: F403
  8from . import _signal_api
  9from . import _delegators
 10__all__ = _signal_api.__all__
 11
 12
 13MODULE_NAME = 'signal'
 14
 15# jax.scipy.signal has only partial coverage of scipy.signal, so we keep the list
 16# of functions we can delegate to JAX
 17# https://jax.readthedocs.io/en/latest/jax.scipy.html
 18JAX_SIGNAL_FUNCS = [
 19    'fftconvolve', 'convolve', 'convolve2d', 'correlate', 'correlate2d',
 20    'csd', 'detrend', 'istft', 'welch'
 21]
 22
 23# some cupyx.scipy.signal functions are incompatible with their scipy counterparts
 24CUPY_BLACKLIST = [
 25    'abcd_normalize', 'bessel', 'besselap', 'envelope', 'get_window', 'lfilter_zi',
 26    'sosfilt_zi', 'remez',
 27]
 28
 29# freqz_sos is a sosfreqz rename, and cupy does not have the new name yet (in v13.x)
 30CUPY_RENAMES = {'freqz_sos': 'sosfreqz'}
 31
 32
 33def delegate_xp(delegator, module_name):
 34    def inner(func):
 35        @functools.wraps(func)
 36        def wrapper(*args, **kwds):
 37            try:
 38                xp = delegator(*args, **kwds)
 39            except TypeError:
 40                # object arrays
 41                if func.__name__ == "tf2ss":
 42                    import numpy as np
 43                    xp = np
 44                else:
 45                    raise
 46
 47            # try delegating to a cupyx/jax namesake
 48            if is_cupy(xp) and func.__name__ not in CUPY_BLACKLIST:
 49                func_name = CUPY_RENAMES.get(func.__name__, func.__name__)
 50
 51                # https://github.com/cupy/cupy/issues/8336
 52                import importlib
 53                cupyx_module = importlib.import_module(f"cupyx.scipy.{module_name}")
 54                cupyx_func = getattr(cupyx_module, func_name)
 55                kwds.pop('xp', None)
 56                return cupyx_func(*args, **kwds)
 57            elif is_jax(xp) and func.__name__ in JAX_SIGNAL_FUNCS:
 58                spx = scipy_namespace_for(xp)
 59                jax_module = getattr(spx, module_name)
 60                jax_func = getattr(jax_module, func.__name__)
 61                kwds.pop('xp', None)
 62                return jax_func(*args, **kwds)
 63            else:
 64                # the original function
 65                return func(*args, **kwds)
 66        return wrapper
 67    return inner
 68
 69
 70# Although most of these functions currently exist in CuPy and some in JAX,
 71# there are no alternative backend tests for any of them in the current
 72# test suite. Each will be documented as np_only until tests are added.
 73untested = {
 74    "argrelextrema",
 75    "argrelmax",
 76    "argrelmin",
 77    "band_stop_obj",
 78    "bode",
 79    "check_NOLA",
 80    "chirp",
 81    "coherence",
 82    "csd",
 83    "czt",
 84    "czt_points",
 85    "dbode",
 86    "dfreqresp",
 87    "dlsim",
 88    "dstep",
 89    "find_peaks",
 90    "find_peaks_cwt",
 91    "freqresp",
 92    "gausspulse",
 93    "iirdesign", # There's no reason this shouldn't work. It just needs tests.
 94    "istft",
 95    "lombscargle",
 96    "lsim",
 97    "max_len_seq",
 98    "peak_prominences",
 99    "peak_widths",
100    "periodogram",
101    "place_poles",
102    "sawtooth",
103    "sepfir2d",
104    "ss2tf",
105    "ss2zpk",
106    "step",
107    "sweep_poly",
108    "symiirorder1",
109    "symiirorder2",
110    "tf2ss",
111    "unit_impulse",
112    "welch",
113    "zoom_fft",
114    "zpk2ss",
115}
116
117
118def get_default_capabilities(func_name, delegator):
119    if delegator is None or func_name in untested:
120        return xp_capabilities(np_only=True)
121    return xp_capabilities()
122
123bilinear_extra_note = \
124    """CuPy does not accept complex inputs.
125
126    """
127
128uses_choose_conv_extra_note = \
129    """CuPy does not support inputs with ``ndim>1`` when ``method="auto"``
130    but does support higher dimensional arrays for ``method="direct"``
131    and ``method="fft"``.
132
133    """
134
135resample_poly_extra_note = \
136    """CuPy only supports ``padtype="constant"``.
137
138    """
139
140upfirdn_extra_note = \
141    """CuPy only supports ``mode="constant"`` and ``cval=0.0``.
142
143    """
144
145xord_extra_note = \
146    """The ``torch`` backend on GPU does not support the case where
147    `wp` and `ws` specify a Bandstop filter.
148
149    """
150
151convolve2d_extra_note = \
152    """The JAX backend only supports ``boundary="fill"`` and ``fillvalue=0``.
153
154    """
155
156zpk2tf_extra_note = \
157    """The CuPy and JAX backends both support only 1d input.
158
159    """
160
161abcd_normalize_extra_note = \
162    """The result dtype when all array inputs are of integer dtype is the
163    backend's current default floating point dtype.
164
165    """
166
167capabilities_overrides = {
168    "abcd_normalize": xp_capabilities(extra_note=abcd_normalize_extra_note),
169    "bessel": xp_capabilities(cpu_only=True, jax_jit=False, allow_dask_compute=True),
170    "bilinear": xp_capabilities(cpu_only=True, exceptions=["cupy"],
171                                jax_jit=False, allow_dask_compute=True,
172                                reason="Uses np.polynomial.Polynomial",
173                                extra_note=bilinear_extra_note),
174    "bilinear_zpk": xp_capabilities(cpu_only=True, exceptions=["cupy", "torch"],
175                                    jax_jit=False, allow_dask_compute=True),
176    "butter": xp_capabilities(cpu_only=True, exceptions=["cupy"], jax_jit=False,
177                              allow_dask_compute=True),
178    "buttord": xp_capabilities(cpu_only=True, exceptions=["cupy", "torch"],
179                               jax_jit=False, allow_dask_compute=True,
180                               extra_note=xord_extra_note),
181    "cheb1ord": xp_capabilities(cpu_only=True, exceptions=["cupy", "torch"],
182                                jax_jit=False, allow_dask_compute=True,
183                                extra_note=xord_extra_note),
184    "cheb2ord": xp_capabilities(cpu_only=True, exceptions=["cupy", "torch"],
185                                jax_jit=False, allow_dask_compute=True,
186                                extra_note=xord_extra_note),
187    "cheby1": xp_capabilities(cpu_only=True, exceptions=["cupy"], jax_jit=False,
188                              allow_dask_compute=True),
189
190    "cheby2": xp_capabilities(cpu_only=True, exceptions=["cupy"], jax_jit=False,
191                              allow_dask_compute=True),
192    "cont2discrete": xp_capabilities(np_only=True, exceptions=["cupy"]),
193    "convolve": xp_capabilities(cpu_only=True, exceptions=["cupy", "jax.numpy"],
194                                allow_dask_compute=True,
195                                extra_note=uses_choose_conv_extra_note),
196    "convolve2d": xp_capabilities(cpu_only=True, exceptions=["cupy", "jax.numpy"],
197                                  allow_dask_compute=True,
198                                  extra_note=convolve2d_extra_note),
199    "correlate": xp_capabilities(cpu_only=True, exceptions=["cupy", "jax.numpy"],
200                                 allow_dask_compute=True,
201                                 extra_note=uses_choose_conv_extra_note),
202    "correlate2d": xp_capabilities(cpu_only=True, exceptions=["cupy", "jax.numpy"],
203                                   allow_dask_compute=True,
204                                   extra_note=convolve2d_extra_note),
205    "correlation_lags": xp_capabilities(out_of_scope=True),
206    "cspline1d": xp_capabilities(cpu_only=True, exceptions=["cupy"],
207                                 jax_jit=False, allow_dask_compute=True),
208    "cspline1d_eval": xp_capabilities(cpu_only=True, exceptions=["cupy"],
209                                      jax_jit=False, allow_dask_compute=True),
210    "cspline2d": xp_capabilities(cpu_only=True, exceptions=["cupy"],
211                                 jax_jit=False, allow_dask_compute=True),
212    "deconvolve": xp_capabilities(cpu_only=True, exceptions=["cupy"],
213                                  jax_jit=False, allow_dask_compute=True),
214    "decimate": xp_capabilities(np_only=True, exceptions=["cupy"]),
215    "detrend": xp_capabilities(cpu_only=True, exceptions=["cupy", "jax.numpy"],
216                               allow_dask_compute=True),
217    "dimpulse": xp_capabilities(np_only=True, exceptions=["cupy"]),
218    "dlti": xp_capabilities(np_only=True,
219                            reason="works in CuPy but delegation isn't set up yet"),
220    "ellip": xp_capabilities(cpu_only=True, exceptions=["cupy"], jax_jit=False,
221                             allow_dask_compute=True,
222                             reason="scipy.special.ellipk"),
223    "ellipord": xp_capabilities(cpu_only=True, exceptions=["cupy"],
224                                jax_jit=False, allow_dask_compute=True,
225                                reason="scipy.special.ellipk"),
226    "findfreqs": xp_capabilities(cpu_only=True, exceptions=["cupy", "torch"],
227                                 jax_jit=False, allow_dask_compute=True),
228    "firls": xp_capabilities(cpu_only=True, allow_dask_compute=True, jax_jit=False,
229                             reason="lstsq"),
230    "firwin": xp_capabilities(cpu_only=True, exceptions=["cupy", "torch"],
231                              jax_jit=False, allow_dask_compute=True),
232    "firwin2": xp_capabilities(cpu_only=True, exceptions=["cupy"],
233                               jax_jit=False, allow_dask_compute=True,
234                               reason="firwin uses np.interp"),
235    "fftconvolve": xp_capabilities(cpu_only=True,
236                                   exceptions=["cupy", "jax.numpy", "torch"]),
237    "freqs": xp_capabilities(cpu_only=True, exceptions=["cupy", "torch"],
238                             jax_jit=False, allow_dask_compute=True),
239    "freqs_zpk": xp_capabilities(cpu_only=True, exceptions=["cupy", "torch"],
240                                 jax_jit=False, allow_dask_compute=True),
241    "freqz": xp_capabilities(cpu_only=True, exceptions=["cupy", "torch"],
242                             jax_jit=False, allow_dask_compute=True),
243    "freqz_sos": xp_capabilities(cpu_only=True, exceptions=["cupy", "torch"],
244                                 jax_jit=False, allow_dask_compute=True),
245    "group_delay": xp_capabilities(cpu_only=True, exceptions=["cupy"],
246                                   jax_jit=False, allow_dask_compute=True),
247    "invres": xp_capabilities(np_only=True, exceptions=["cupy"]),
248    "invresz": xp_capabilities(np_only=True, exceptions=["cupy"]),
249    "iircomb": xp_capabilities(xfail_backends=[("jax.numpy", "inaccurate")]),
250    "iirfilter": xp_capabilities(cpu_only=True, exceptions=["cupy", "torch"],
251                                 jax_jit=False, allow_dask_compute=True),
252    "kaiser_atten": xp_capabilities(
253        out_of_scope=True, reason="scalars in, scalars out"
254    ),
255    "kaiser_beta": xp_capabilities(out_of_scope=True, reason="scalars in, scalars out"),
256    "kaiserord": xp_capabilities(out_of_scope=True, reason="scalars in, scalars out"),
257    "lfilter": xp_capabilities(cpu_only=True, exceptions=["cupy"],
258                               allow_dask_compute=True, jax_jit=False),
259    "lfilter_zi": xp_capabilities(cpu_only=True, allow_dask_compute=True,
260                                  jax_jit=False),
261    "lfiltic": xp_capabilities(cpu_only=True, exceptions=["cupy"],
262                               allow_dask_compute=True),
263    "lp2bp": xp_capabilities(cpu_only=True, exceptions=["cupy", "torch"],
264                             allow_dask_compute=True, jax_jit=False),
265    "lp2bp_zpk": xp_capabilities(cpu_only=True, exceptions=["cupy", "torch"],
266                                 allow_dask_compute=True, jax_jit=False),
267    "lp2bs": xp_capabilities(cpu_only=True, exceptions=["cupy", "torch"],
268                             allow_dask_compute=True, jax_jit=False),
269    "lp2bs_zpk": xp_capabilities(cpu_only=True, exceptions=["cupy", "torch"],
270                                 allow_dask_compute=True, jax_jit=False),
271    "lp2lp": xp_capabilities(cpu_only=True, exceptions=["cupy", "torch"],
272                             allow_dask_compute=True, jax_jit=False),
273    "lp2lp_zpk": xp_capabilities(cpu_only=True, exceptions=["cupy", "torch"],
274                                 allow_dask_compute=True, jax_jit=False),
275    "lp2hp": xp_capabilities(cpu_only=True, exceptions=["cupy", "torch"],
276                             allow_dask_compute=True, jax_jit=False),
277    "lp2hp_zpk": xp_capabilities(cpu_only=True, exceptions=["cupy", "torch"],
278                                 allow_dask_compute=True, jax_jit=False),
279    "lti": xp_capabilities(np_only=True,
280                            reason="works in CuPy but delegation isn't set up yet"),
281    "medfilt": xp_capabilities(cpu_only=True, exceptions=["cupy"],
282                               allow_dask_compute=True, jax_jit=False,
283                               reason="uses scipy.ndimage.rank_filter"),
284    "medfilt2d": xp_capabilities(cpu_only=True, exceptions=["cupy"],
285                                 allow_dask_compute=True, jax_jit=False,
286                                 reason="c extension module"),
287    "minimum_phase": xp_capabilities(cpu_only=True, exceptions=["cupy", "torch"],
288                                     allow_dask_compute=True, jax_jit=False),
289    "normalize": xp_capabilities(cpu_only=True, exceptions=["cupy", "torch"],
290                                 jax_jit=False, allow_dask_compute=True),
291    "oaconvolve": xp_capabilities(
292        cpu_only=True, exceptions=["cupy", "torch"],
293        xfail_backends=[("dask.array", "wrong answer")],
294    ),
295    "order_filter": xp_capabilities(cpu_only=True, exceptions=["cupy"],
296                                    allow_dask_compute=True, jax_jit=False,
297                                    reason="uses scipy.ndimage.rank_filter"),
298    "qspline1d": xp_capabilities(cpu_only=True, exceptions=["cupy"],
299                                 jax_jit=False, allow_dask_compute=True),
300    "qspline1d_eval": xp_capabilities(cpu_only=True, exceptions=["cupy"],
301                                      jax_jit=False, allow_dask_compute=True),
302    "qspline2d": xp_capabilities(np_only=True, exceptions=["cupy"]),
303    "remez": xp_capabilities(cpu_only=True, allow_dask_compute=True, jax_jit=False),
304    "resample": xp_capabilities(
305        cpu_only=True, exceptions=["cupy"],
306        skip_backends=[
307            ("dask.array", "XXX something in dask"),
308            ("jax.numpy", "XXX: immutable arrays"),
309        ]
310    ),
311    "resample_poly": xp_capabilities(
312        cpu_only=True, exceptions=["cupy"],
313        jax_jit=False, skip_backends=[("dask.array", "XXX something in dask")],
314        extra_note=resample_poly_extra_note,
315    ),
316    "residue": xp_capabilities(np_only=True, exceptions=["cupy"]),
317    "residuez": xp_capabilities(np_only=True, exceptions=["cupy"]),
318    "savgol_filter": xp_capabilities(cpu_only=True, exceptions=["cupy"],
319                                     jax_jit=False,
320                                     reason="convolve1d is cpu-only"),
321    "sawtooth": xp_capabilities(jax_jit=False,
322                                skip_backends=[("dask.array", "dask tests fail")]),
323    "sepfir2d": xp_capabilities(np_only=True),
324    "sos2zpk": xp_capabilities(cpu_only=True, exceptions=["cupy"], jax_jit=False,
325                               allow_dask_compute=True),
326    "sos2tf": xp_capabilities(cpu_only=True, exceptions=["cupy"], jax_jit=False,
327                              allow_dask_compute=True),
328    "sosfilt": xp_capabilities(cpu_only=True, exceptions=["cupy"], jax_jit=False,
329                               allow_dask_compute=True),
330    "sosfilt_zi": xp_capabilities(cpu_only=True, allow_dask_compute=True,
331                                  jax_jit=False),
332    "sosfiltfilt": xp_capabilities(
333        cpu_only=True, exceptions=["cupy"],
334        skip_backends=[
335            (
336                "dask.array",
337                "sosfiltfilt directly sets shape attributes on arrays"
338                " which dask doesn't like"
339            ),
340            ("torch", "negative strides"),
341            ("jax.numpy", "sosfilt works in-place"),
342        ],
343    ),
344    "sosfreqz": xp_capabilities(cpu_only=True, exceptions=["cupy", "torch"],
345                                jax_jit=False, allow_dask_compute=True),
346    "spline_filter": xp_capabilities(cpu_only=True, exceptions=["cupy"],
347                                     jax_jit=False, allow_dask_compute=True),
348    "tf2sos": xp_capabilities(cpu_only=True, exceptions=["cupy"], jax_jit=False,
349                              allow_dask_compute=True),
350    "tf2zpk": xp_capabilities(cpu_only=True, exceptions=["cupy"], jax_jit=False,
351                              allow_dask_compute=True),
352    "unique_roots": xp_capabilities(np_only=True, exceptions=["cupy"]),
353    "upfirdn": xp_capabilities(cpu_only=True, exceptions=["cupy"], jax_jit=False,
354                               allow_dask_compute=True,
355                               reason="Cython implementation",
356                               extra_note=upfirdn_extra_note),
357    "vectorstrength": xp_capabilities(cpu_only=True, exceptions=["cupy", "torch"],
358                                      allow_dask_compute=True, jax_jit=False),
359    "wiener": xp_capabilities(cpu_only=True, exceptions=["cupy", "jax.numpy"],
360                              allow_dask_compute=True, jax_jit=False,
361                              reason="uses scipy.signal.correlate"),
362    "zpk2sos": xp_capabilities(cpu_only=True, exceptions=["cupy"], jax_jit=False,
363                               allow_dask_compute=True),
364    "zpk2tf": xp_capabilities(cpu_only=True, exceptions=["cupy"], jax_jit=False,
365                              allow_dask_compute=True,
366                              extra_note=zpk2tf_extra_note),
367    "spectrogram": xp_capabilities(out_of_scope=True),  # legacy
368    "stft": xp_capabilities(out_of_scope=True),  # legacy
369    "istft": xp_capabilities(out_of_scope=True),  # legacy
370    "check_COLA": xp_capabilities(out_of_scope=True),  # legacy
371}
372
373
374# ### decorate ###
375for obj_name in _signal_api.__all__:
376    bare_obj = getattr(_signal_api, obj_name)
377    delegator = getattr(_delegators, obj_name + "_signature", None)
378
379    if SCIPY_ARRAY_API and delegator is not None:
380        f = delegate_xp(delegator, MODULE_NAME)(bare_obj)
381    else:
382        f = bare_obj
383
384    if not isinstance(f, types.ModuleType):
385        capabilities = capabilities_overrides.get(
386            obj_name, get_default_capabilities(obj_name, delegator)
387        )
388        f = capabilities(f)  # pyrefly:ignore[not-callable]
389
390    # add the decorated function to the namespace, to be imported in __init__.py
391    vars()[obj_name] = f

Note that a function will only be decorated if the environment variable SCIPY_ARRAY_API is set and its signature is listed in the file scipy/signal/_delegators.py. E.g., for firwin, the signature function looks like this:

339def firwin_signature(numtaps, cutoff, *args, **kwds):
340    if isinstance(cutoff, int | float):
341        xp = np_compat
342    else:
343        xp = array_namespace(cutoff)
344    return xp

Support on CPU#

Legend

✔️ = supported

✖ = unsupported

N/A = out-of-scope

function/class

torch

jax

dask

CZT

ShortTimeFFT

StateSpace

TransferFunction

ZerosPolesGain

ZoomFFT

abcd_normalize

✔️

✔️

✔️

argrelextrema

argrelmax

argrelmin

band_stop_obj

bessel

✔️

✔️

✔️

besselap

✔️

✔️

✔️

bilinear

✔️

✔️

✔️

bilinear_zpk

✔️

✔️

✔️

bode

buttap

✔️

✔️

✔️

butter

✔️

✔️

✔️

buttord

✔️

✔️

✔️

cheb1ap

✔️

✔️

✔️

cheb1ord

✔️

✔️

✔️

cheb2ap

✔️

✔️

✔️

cheb2ord

✔️

✔️

✔️

cheby1

✔️

✔️

✔️

cheby2

✔️

✔️

✔️

check_COLA

N/A

N/A

N/A

check_NOLA

chirp

choose_conv_method

✔️

✔️

✔️

closest_STFT_dual_window

coherence

cont2discrete

convolve

✔️

✔️

✔️

convolve2d

✔️

✔️

✔️

correlate

✔️

✔️

✔️

correlate2d

✔️

✔️

✔️

correlation_lags

N/A

N/A

N/A

csd

cspline1d

✔️

✔️

✔️

cspline1d_eval

✔️

✔️

✔️

cspline2d

✔️

✔️

✔️

czt

czt_points

dbode

decimate

deconvolve

✔️

✔️

✔️

detrend

✔️

✔️

✔️

dfreqresp

dimpulse

dlsim

dlti

dstep

ellip

✔️

✔️

✔️

ellipap

✔️

✔️

✔️

ellipord

✔️

✔️

✔️

envelope

✔️

✔️

✔️

fftconvolve

✔️

✔️

✔️

filtfilt

✔️

✔️

✔️

find_peaks

find_peaks_cwt

findfreqs

✔️

✔️

✔️

firls

✔️

✔️

✔️

firwin

✔️

✔️

✔️

firwin2

✔️

✔️

✔️

firwin_2d

freqresp

freqs

✔️

✔️

✔️

freqs_zpk

✔️

✔️

✔️

freqz

✔️

✔️

✔️

freqz_sos

✔️

✔️

✔️

freqz_zpk

✔️

✔️

✔️

gammatone

✔️

✔️

✔️

gauss_spline

✔️

✔️

✔️

gausspulse

get_window

✔️

✔️

✔️

group_delay

✔️

✔️

✔️

hilbert

✔️

✔️

✔️

hilbert2

✔️

✔️

✔️

iircomb

✔️

✔️

iirdesign

iirfilter

✔️

✔️

✔️

iirnotch

✔️

✔️

✔️

iirpeak

✔️

✔️

✔️

impulse

✔️

✔️

✔️

invres

invresz

istft

N/A

N/A

N/A

kaiser_atten

N/A

N/A

N/A

kaiser_beta

N/A

N/A

N/A

kaiserord

N/A

N/A

N/A

lfilter

✔️

✔️

✔️

lfilter_zi

✔️

✔️

✔️

lfiltic

✔️

✔️

✔️

lombscargle

lp2bp

✔️

✔️

✔️

lp2bp_zpk

✔️

✔️

✔️

lp2bs

✔️

✔️

✔️

lp2bs_zpk

✔️

✔️

✔️

lp2hp

✔️

✔️

✔️

lp2hp_zpk

✔️

✔️

✔️

lp2lp

✔️

✔️

✔️

lp2lp_zpk

✔️

✔️

✔️

lsim

lti

max_len_seq

medfilt

✔️

✔️

✔️

medfilt2d

✔️

✔️

✔️

minimum_phase

✔️

✔️

✔️

normalize

✔️

✔️

✔️

oaconvolve

✔️

✔️

order_filter

✔️

✔️

✔️

peak_prominences

peak_widths

periodogram

place_poles

qspline1d

✔️

✔️

✔️

qspline1d_eval

✔️

✔️

✔️

qspline2d

remez

✔️

✔️

✔️

resample

✔️

resample_poly

✔️

✔️

residue

residuez

savgol_coeffs

✔️

✔️

✔️

savgol_filter

✔️

✔️

✔️

sawtooth

✔️

✔️

sepfir2d

sos2tf

✔️

✔️

✔️

sos2zpk

✔️

✔️

✔️

sosfilt

✔️

✔️

✔️

sosfilt_zi

✔️

✔️

✔️

sosfiltfilt

sosfreqz

✔️

✔️

✔️

spectrogram

N/A

N/A

N/A

spline_filter

✔️

✔️

✔️

square

✔️

✔️

✔️

ss2tf

ss2zpk

step

stft

N/A

N/A

N/A

sweep_poly

symiirorder1

symiirorder2

tf2sos

✔️

✔️

✔️

tf2ss

tf2zpk

✔️

✔️

✔️

unique_roots

unit_impulse

upfirdn

✔️

✔️

✔️

vectorstrength

✔️

✔️

✔️

welch

whittaker_henderson

wiener

✔️

✔️

✔️

zoom_fft

zpk2sos

✔️

✔️

✔️

zpk2ss

zpk2tf

✔️

✔️

✔️

Support on GPU#

Legend

✔️ = supported

✖ = unsupported

N/A = out-of-scope

function/class

cupy

torch

jax

CZT

ShortTimeFFT

StateSpace

TransferFunction

ZerosPolesGain

ZoomFFT

abcd_normalize

✔️

✔️

✔️

argrelextrema

argrelmax

argrelmin

band_stop_obj

bessel

besselap

✔️

✔️

✔️

bilinear

✔️

bilinear_zpk

✔️

✔️

bode

buttap

✔️

✔️

✔️

butter

✔️

buttord

✔️

✔️

cheb1ap

✔️

✔️

✔️

cheb1ord

✔️

✔️

cheb2ap

✔️

✔️

✔️

cheb2ord

✔️

✔️

cheby1

✔️

cheby2

✔️

check_COLA

N/A

N/A

N/A

check_NOLA

chirp

choose_conv_method

✔️

✔️

✔️

closest_STFT_dual_window

coherence

cont2discrete

✔️

convolve

✔️

✔️

convolve2d

✔️

✔️

correlate

✔️

✔️

correlate2d

✔️

✔️

correlation_lags

N/A

N/A

N/A

csd

cspline1d

✔️

cspline1d_eval

✔️

cspline2d

✔️

czt

czt_points

dbode

decimate

✔️

deconvolve

✔️

detrend

✔️

✔️

dfreqresp

dimpulse

✔️

dlsim

dlti

dstep

ellip

✔️

ellipap

✔️

✔️

✔️

ellipord

✔️

envelope

✔️

✔️

✔️

fftconvolve

✔️

✔️

✔️

filtfilt

✔️

✔️

✔️

find_peaks

find_peaks_cwt

findfreqs

✔️

✔️

firls

firwin

✔️

✔️

firwin2

✔️

firwin_2d

freqresp

freqs

✔️

✔️

freqs_zpk

✔️

✔️

freqz

✔️

✔️

freqz_sos

✔️

✔️

freqz_zpk

✔️

✔️

✔️

gammatone

✔️

✔️

✔️

gauss_spline

✔️

✔️

✔️

gausspulse

get_window

✔️

✔️

✔️

group_delay

✔️

hilbert

✔️

✔️

✔️

hilbert2

✔️

✔️

✔️

iircomb

✔️

✔️

iirdesign

iirfilter

✔️

✔️

iirnotch

✔️

✔️

✔️

iirpeak

✔️

✔️

✔️

impulse

✔️

✔️

✔️

invres

✔️

invresz

✔️

istft

N/A

N/A

N/A

kaiser_atten

N/A

N/A

N/A

kaiser_beta

N/A

N/A

N/A

kaiserord

N/A

N/A

N/A

lfilter

✔️

lfilter_zi

lfiltic

✔️

lombscargle

lp2bp

✔️

✔️

lp2bp_zpk

✔️

✔️

lp2bs

✔️

✔️

lp2bs_zpk

✔️

✔️

lp2hp

✔️

✔️

lp2hp_zpk

✔️

✔️

lp2lp

✔️

✔️

lp2lp_zpk

✔️

✔️

lsim

lti

max_len_seq

medfilt

✔️

medfilt2d

✔️

minimum_phase

✔️

✔️

normalize

✔️

✔️

oaconvolve

✔️

✔️

order_filter

✔️

peak_prominences

peak_widths

periodogram

place_poles

qspline1d

✔️

qspline1d_eval

✔️

qspline2d

✔️

remez

resample

✔️

resample_poly

✔️

residue

✔️

residuez

✔️

savgol_coeffs

✔️

✔️

✔️

savgol_filter

✔️

sawtooth

✔️

✔️

✔️

sepfir2d

sos2tf

✔️

sos2zpk

✔️

sosfilt

✔️

sosfilt_zi

sosfiltfilt

✔️

sosfreqz

✔️

✔️

spectrogram

N/A

N/A

N/A

spline_filter

✔️

square

✔️

✔️

✔️

ss2tf

ss2zpk

step

stft

N/A

N/A

N/A

sweep_poly

symiirorder1

symiirorder2

tf2sos

✔️

tf2ss

tf2zpk

✔️

unique_roots

✔️

unit_impulse

upfirdn

✔️

vectorstrength

✔️

✔️

welch

whittaker_henderson

wiener

✔️

✔️

zoom_fft

zpk2sos

✔️

zpk2ss

zpk2tf

✔️

Support with JIT#

Legend

✔️ = supported

✖ = unsupported

N/A = out-of-scope

function/class

jax

CZT

ShortTimeFFT

StateSpace

TransferFunction

ZerosPolesGain

ZoomFFT

abcd_normalize

✔️

argrelextrema

argrelmax

argrelmin

band_stop_obj

bessel

besselap

✔️

bilinear

bilinear_zpk

bode

buttap

✔️

butter

buttord

cheb1ap

✔️

cheb1ord

cheb2ap

✔️

cheb2ord

cheby1

cheby2

check_COLA

N/A

check_NOLA

chirp

choose_conv_method

✔️

closest_STFT_dual_window

coherence

cont2discrete

convolve

✔️

convolve2d

✔️

correlate

✔️

correlate2d

✔️

correlation_lags

N/A

csd

cspline1d

cspline1d_eval

cspline2d

czt

czt_points

dbode

decimate

deconvolve

detrend

✔️

dfreqresp

dimpulse

dlsim

dlti

dstep

ellip

ellipap

✔️

ellipord

envelope

✔️

fftconvolve

✔️

filtfilt

✔️

find_peaks

find_peaks_cwt

findfreqs

firls

firwin

firwin2

firwin_2d

freqresp

freqs

freqs_zpk

freqz

freqz_sos

freqz_zpk

✔️

gammatone

✔️

gauss_spline

✔️

gausspulse

get_window

✔️

group_delay

hilbert

✔️

hilbert2

✔️

iircomb

iirdesign

iirfilter

iirnotch

✔️

iirpeak

✔️

impulse

✔️

invres

invresz

istft

N/A

kaiser_atten

N/A

kaiser_beta

N/A

kaiserord

N/A

lfilter

lfilter_zi

lfiltic

✔️

lombscargle

lp2bp

lp2bp_zpk

lp2bs

lp2bs_zpk

lp2hp

lp2hp_zpk

lp2lp

lp2lp_zpk

lsim

lti

max_len_seq

medfilt

medfilt2d

minimum_phase

normalize

oaconvolve

✔️

order_filter

peak_prominences

peak_widths

periodogram

place_poles

qspline1d

qspline1d_eval

qspline2d

remez

resample

resample_poly

residue

residuez

savgol_coeffs

✔️

savgol_filter

sawtooth

sepfir2d

sos2tf

sos2zpk

sosfilt

sosfilt_zi

sosfiltfilt

sosfreqz

spectrogram

N/A

spline_filter

square

✔️

ss2tf

ss2zpk

step

stft

N/A

sweep_poly

symiirorder1

symiirorder2

tf2sos

tf2ss

tf2zpk

unique_roots

unit_impulse

upfirdn

vectorstrength

welch

whittaker_henderson

wiener

zoom_fft

zpk2sos

zpk2ss

zpk2tf