Sep 27, 2021 · Sep 27, 2021
diff --git a/doc/api/next_api_changes/deprecations/ZZZZZ-AL.rst b/doc/api/next_api_changes/deprecations/ZZZZZ-AL.rst
 ``mlab.stride_windows``
 ~~~~~~~~~~~~~~~~~~~~~~~
 ... is deprecated.  Use ``np.lib.stride_tricks.sliding_window_view`` instead
 (or ``np.lib.stride_tricks.as_strided`` on numpy<1.20).
diff --git a/lib/matplotlib/mlab.py b/lib/matplotlib/mlab.py
    return y - (b*x + a)


 @_api.deprecated("3.6")
 def stride_windows(x, n, noverlap=None, axis=0):
    """
    Get all windows of x with length n as a single array,
    """
    if noverlap is None:
        noverlap = 0
    if np.ndim(x) != 1:
        raise ValueError('only 1-dimensional arrays can be used')
    return _stride_windows(x, n, noverlap, axis)


 def _stride_windows(x, n, noverlap=0, axis=0):
    # np>=1.20 provides sliding_window_view, and we only ever use axis=0.
    if hasattr(np.lib.stride_tricks, "sliding_window_view") and axis == 0:
        if noverlap >= n:
            raise ValueError('noverlap must be less than n')
        return np.lib.stride_tricks.sliding_window_view(
            x, n, axis=0)[::n - noverlap].T

    if noverlap >= n:
        raise ValueError('noverlap must be less than n')

    x = np.asarray(x)

    if x.ndim != 1:
        raise ValueError('only 1-dimensional arrays can be used')
    if n == 1 and noverlap == 0:
        if axis == 0:
            return x[np.newaxis]
        raise ValueError(
            "The window length must match the data's first dimension")

    result =stride_windows(x, NFFT, noverlap, axis=0)
    result =_stride_windows(x, NFFT, noverlap)
    result = detrend(result, detrend_func, axis=0)
    result = result * window.reshape((-1, 1))
    result = np.fft.fft(result, n=pad_to, axis=0)[:numFreqs, :]
    freqs = np.fft.fftfreq(pad_to, 1/Fs)[:numFreqs]

    if not same_data:
        # if same_data is False, mode must be 'psd'
        resultY =stride_windows(y, NFFT, noverlap)
        resultY =_stride_windows(y, NFFT, noverlap)
        resultY = detrend(resultY, detrend_func, axis=0)
        resultY = resultY * window.reshape((-1, 1))
        resultY = np.fft.fft(resultY, n=pad_to, axis=0)[:numFreqs, :]
diff --git a/lib/matplotlib/tests/test_mlab.py b/lib/matplotlib/tests/test_mlab.py
 import numpy as np
 import pytest

 import matplotlib.mlab as mlab
 from matplotlib import mlab, _api


 class TestStride:
            y = y.base
        return y

    @pytest.fixture(autouse=True)
    def stride_is_deprecated(self):
        with _api.suppress_matplotlib_deprecation_warning():
            yield

    def calc_window_target(self, x, NFFT, noverlap=0, axis=0):
        """
        This is an adaptation of the original window extraction algorithm.
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1,4 @@
		``mlab.stride_windows``
		~~~~~~~~~~~~~~~~~~~~~~~
		... is deprecated. Use ``np.lib.stride_tricks.sliding_window_view`` instead
		(or ``np.lib.stride_tricks.as_strided`` on numpy<1.20).
Original file line number	Diff line number	Diff line change
Expand Up		@@ -215,6 +215,7 @@ def detrend_linear(y):
		return y - (b*x + a)


		@_api.deprecated("3.6")
		def stride_windows(x, n, noverlap=None, axis=0):
		"""
		Get all windows of x with length n as a single array,
Expand DownExpand Up		@@ -246,6 +247,18 @@ def stride_windows(x, n, noverlap=None, axis=0):
		"""
		if noverlap is None:
		noverlap = 0
		if np.ndim(x) != 1:
		raise ValueError('only 1-dimensional arrays can be used')
		return _stride_windows(x, n, noverlap, axis)


		def _stride_windows(x, n, noverlap=0, axis=0):
		# np>=1.20 provides sliding_window_view, and we only ever use axis=0.
		if hasattr(np.lib.stride_tricks, "sliding_window_view") and axis == 0:
		if noverlap >= n:
		raise ValueError('noverlap must be less than n')
		return np.lib.stride_tricks.sliding_window_view(
		x, n, axis=0)[::n - noverlap].T

		if noverlap >= n:
		raise ValueError('noverlap must be less than n')
Expand All		@@ -254,8 +267,6 @@ def stride_windows(x, n, noverlap=None, axis=0):

		x = np.asarray(x)

		if x.ndim != 1:
		raise ValueError('only 1-dimensional arrays can be used')
		if n == 1 and noverlap == 0:
		if axis == 0:
		return x[np.newaxis]
Expand DownExpand Up		@@ -370,15 +381,15 @@ def _spectral_helper(x, y=None, NFFT=None, Fs=None, detrend_func=None,
		raise ValueError(
		"The window length must match the data's first dimension")

		result =stride_windows(x, NFFT, noverlap, axis=0)
		result =_stride_windows(x, NFFT, noverlap)
		result = detrend(result, detrend_func, axis=0)
		result = result * window.reshape((-1, 1))
		result = np.fft.fft(result, n=pad_to, axis=0)[:numFreqs, :]
		freqs = np.fft.fftfreq(pad_to, 1/Fs)[:numFreqs]

		if not same_data:
		# if same_data is False, mode must be 'psd'
		resultY =stride_windows(y, NFFT, noverlap)
		resultY =_stride_windows(y, NFFT, noverlap)
		resultY = detrend(resultY, detrend_func, axis=0)
		resultY = resultY * window.reshape((-1, 1))
		resultY = np.fft.fft(resultY, n=pad_to, axis=0)[:numFreqs, :]
Expand Down
Original file line number	Diff line number	Diff line change
Expand Up		@@ -3,7 +3,7 @@
		import numpy as np
		import pytest

		import matplotlib.mlab as mlab
		from matplotlib import mlab, _api


		class TestStride:
Expand All		@@ -13,6 +13,11 @@ def get_base(self, x):
		y = y.base
		return y

		@pytest.fixture(autouse=True)
		def stride_is_deprecated(self):
		with _api.suppress_matplotlib_deprecation_warning():
		yield

		def calc_window_target(self, x, NFFT, noverlap=0, axis=0):
		"""
		This is an adaptation of the original window extraction algorithm.
Expand Down