ENH: uarray support for scipy.signal

.github/workflows/docker.yml

@@ -14,7 +14,7 @@ jobs:
     name: Build base Docker image
     runs-on: ubuntu-latest
     environment: scipy-dev
-    if: "github.repository_owner == 'scipy' && !contains(github.event.head_commit.message, '[ci skip]') && !contains(github.event.head_commit.message, '[skip ci]') && !contains(github.event.head_commit.message, '[skip github]')"
+    if: "github.repository_owner == 'rgommers' && !contains(github.event.head_commit.message, '[ci skip]') && !contains(github.event.head_commit.message, '[skip ci]') && !contains(github.event.head_commit.message, '[skip github]')"
     steps:
       - name: Clone repository
         uses: actions/checkout@v2

.github/workflows/gitpod.yml

@@ -6,16 +6,16 @@ on:
 
 jobs:
   build:
-    name: Build Gitpod Docker image 
+    name: Build Gitpod Docker image
     runs-on: ubuntu-latest
     environment: scipy-dev
-    if: "github.repository_owner == 'scipy' && !contains(github.event.head_commit.message, '[ci skip]') && !contains(github.event.head_commit.message, '[skip ci]') && !contains(github.event.head_commit.message, '[skip github]')"
+    if: "github.repository_owner == 'rgommers' && !contains(github.event.head_commit.message, '[ci skip]') && !contains(github.event.head_commit.message, '[skip ci]') && !contains(github.event.head_commit.message, '[skip github]')"
     steps:
       - name: Clone repository
         uses: actions/checkout@v2
-      - name: Lint Docker 
+      - name: Lint Docker
         uses: brpaz/[email protected]
-        with: 
+        with:
           dockerfile: ./tools/docker_dev/gitpod.Dockerfile
       - name: Get refs
         shell: bash
@@ -49,6 +49,6 @@ jobs:
           cache-to: type=local,dest=/tmp/.buildx-cache
           tags: |
             scipy/scipy-gitpod:${{ steps.getrefs.outputs.date }}-${{ steps.getrefs.outputs.branch}}-${{ steps.getrefs.outputs.sha8 }}, scipy/scipy-gitpod:latest
-      - name: Image digest 
+      - name: Image digest
         # Return details of the image build: sha and shell
         run: echo ${{ steps.docker_build.outputs.digest }}

.github/workflows/linux.yml

@@ -13,7 +13,7 @@ on:
 jobs:
   Python-38-dbg:
     name: Python 3.8-dbg
-    if: "github.repository == 'scipy/scipy' && !contains(github.event.head_commit.message, '[ci skip]') && !contains(github.event.head_commit.message, '[skip ci]') && !contains(github.event.head_commit.message, '[skip github]')"
+    if: "github.repository == 'rgommers/scipy' && !contains(github.event.head_commit.message, '[ci skip]') && !contains(github.event.head_commit.message, '[skip ci]') && !contains(github.event.head_commit.message, '[skip github]')"
     runs-on: ubuntu-18.04
     steps:
       - uses: actions/checkout@v2
@@ -53,7 +53,7 @@ jobs:
 
   test_numpy_main:
     name: NumPy main
-    if: "github.repository == 'scipy/scipy' && !contains(github.event.head_commit.message, '[ci skip]') && !contains(github.event.head_commit.message, '[skip ci]') && !contains(github.event.head_commit.message, '[skip github]') && !contains(github.ref, 'maintenance/') && !contains(github.base_ref, 'maintenance/')"
+    if: "github.repository == 'rgommers/scipy' && !contains(github.event.head_commit.message, '[ci skip]') && !contains(github.event.head_commit.message, '[skip ci]') && !contains(github.event.head_commit.message, '[skip github]') && !contains(github.ref, 'maintenance/') && !contains(github.base_ref, 'maintenance/')"
     runs-on: ubuntu-latest
     strategy:
       matrix:

.github/workflows/macos.yml

@@ -14,7 +14,7 @@ on:
 jobs:
   test_macos:
     name: macOS Test Matrix
-    if: "github.repository == 'scipy/scipy' && !contains(github.event.head_commit.message, '[ci skip]') && !contains(github.event.head_commit.message, '[skip ci]') && !contains(github.event.head_commit.message, '[skip github]')"
+    if: "github.repository == 'rgommers/scipy' && !contains(github.event.head_commit.message, '[ci skip]') && !contains(github.event.head_commit.message, '[skip ci]') && !contains(github.event.head_commit.message, '[skip github]')"
     runs-on: macos-latest
     strategy:
       max-parallel: 3

mypy.ini

@@ -199,6 +199,9 @@ ignore_errors = True
 [mypy-scipy._build_utils.tempita]
 ignore_errors = True
 
+[mypy-scipy.signal._api]
+ignore_errors = True
+
 [mypy-scipy.signal.tests.test_signaltools]
 ignore_errors = True
 

scipy/signal/__init__.py

@@ -307,24 +307,22 @@
 
 """
 from . import _sigtools, windows
-from ._waveforms import *
 from ._max_len_seq import max_len_seq
-from ._upfirdn import upfirdn
+from ._multimethods import *
 
 from ._spline import (  # noqa: F401
     cspline2d,
     qspline2d,
-    sepfir2d,
     symiirorder1,
     symiirorder2,
 )
 
+from ._backend import *
 from ._bsplines import *
 from ._filter_design import *
 from ._fir_filter_design import *
 from ._ltisys import *
 from ._lti_conversion import *
-from ._signaltools import *
 from ._savitzky_golay import savgol_coeffs, savgol_filter
 from ._spectral_py import *
 from ._wavelets import *

scipy/signal/_api.py

@@ -0,0 +1,4 @@
+from ._upfirdn import upfirdn
+from ._spline import sepfir2d
+from ._signaltools import *
+from ._waveforms import *

scipy/signal/_backend.py

@@ -0,0 +1,112 @@
+import scipy._lib.uarray as ua
+from scipy.signal import _api
+import numpy as np
+
+__all__ = [
+    'register_backend', 'set_backend',
+    'set_global_backend', 'skip_backend'
+]
+
+
+class scalar_or_array:
+    """
+    Special case argument that can be either a scalar or array
+    for __ua_convert__.
+    """
+    pass
+
+
+class tuple_str_array:
+    """
+    Special case argument that can be either a string, tuple or array
+    for __ua_convert__.
+    """
+    pass
+
+
+class _ScipySignalBackend:
+    __ua_domain__ = "numpy.scipy.signal"
+
+
+    @staticmethod
+    def __ua_function__(method, args, kwargs):
+        fn = getattr(_api, method.__name__, None)
+
+        if fn is None:
+            return NotImplemented
+
+        return fn(*args, **kwargs)
+
+
+    @ua.wrap_single_convertor
+    def __ua_convert__(value, dispatch_type, coerce):
+        if value is None:
+            return None
+
+        if dispatch_type is np.ndarray:
+            if not coerce and not isinstance(value, np.ndarray):
+                return NotImplemented
+
+            return np.asarray(value)
+
+        elif dispatch_type is np.dtype:
+            return np.dtype(value)
+
+        elif dispatch_type is scalar_or_array:
+            if np.isscalar(value):
+                return value
+            elif not coerce and not isinstance(value, np.ndarray):
+                return NotImplemented
+
+            return np.asarray(value)
+
+        elif dispatch_type is tuple_str_array:
+            if np.isscalar(value) or isinstance(value, (str, tuple)):
+                return value
+            elif not coerce and not isinstance(value, np.ndarray):
+                return NotImplemented
+
+            return np.asarray(value)
+
+        return value
+
+
+_named_backends = {
+    'scipy': _ScipySignalBackend,
+}
+
+
+def _backend_from_arg(backend):
+    if isinstance(backend, str):
+        try:
+            backend = _named_backends[backend]
+        except KeyError as e:
+            raise ValueError('Unknown backend {}'.format(backend)) from e
+
+    if backend.__ua_domain__ != 'numpy.scipy.signal':
+        raise ValueError('Backend does not implement "numpy.scipy.signal"')
+
+    return backend
+
+
+def set_global_backend(backend, coerce=False, only=False, try_last=False):
+    backend = _backend_from_arg(backend)
+    ua.set_global_backend(backend, coerce=coerce, only=only, try_last=try_last)
+
+
+def register_backend(backend):
+    backend = _backend_from_arg(backend)
+    ua.register_backend(backend)
+
+
+def set_backend(backend, coerce=True, only=False):
+    backend = _backend_from_arg(backend)
+    return ua.set_backend(backend, coerce=coerce, only=only)
+
+
+def skip_backend(backend):
+    backend = _backend_from_arg(backend)
+    return ua.skip_backend(backend)
+
+
+set_global_backend('scipy', coerce=True, try_last=True)