Fixed database typo and removed unnecessary class identifier.

venv/Lib/site-packages/scipy/fft/_pocketfft/tests/test_real_transforms.py

@@ -0,0 +1,487 @@
+from os.path import join, dirname
+
+import numpy as np
+from numpy.testing import (
+    assert_array_almost_equal, assert_equal, assert_allclose)
+import pytest
+from pytest import raises as assert_raises
+
+from scipy.fft._pocketfft.realtransforms import (
+    dct, idct, dst, idst, dctn, idctn, dstn, idstn)
+
+fftpack_test_dir = join(dirname(__file__), '..', '..', '..', 'fftpack', 'tests')
+
+MDATA_COUNT = 8
+FFTWDATA_COUNT = 14
+
+def is_longdouble_binary_compatible():
+    try:
+        one = np.frombuffer(
+            b'\x00\x00\x00\x00\x00\x00\x00\x80\xff\x3f\x00\x00\x00\x00\x00\x00',
+            dtype='<f16')
+        return one == np.longfloat(1.)
+    except TypeError:
+        return False
+
+
+def get_reference_data():
+    ref = getattr(globals(), '__reference_data', None)
+    if ref is not None:
+        return ref
+
+    # Matlab reference data
+    MDATA = np.load(join(fftpack_test_dir, 'test.npz'))
+    X = [MDATA['x%d' % i] for i in range(MDATA_COUNT)]
+    Y = [MDATA['y%d' % i] for i in range(MDATA_COUNT)]
+
+    # FFTW reference data: the data are organized as follows:
+    #    * SIZES is an array containing all available sizes
+    #    * for every type (1, 2, 3, 4) and every size, the array dct_type_size
+    #    contains the output of the DCT applied to the input np.linspace(0, size-1,
+    #    size)
+    FFTWDATA_DOUBLE = np.load(join(fftpack_test_dir, 'fftw_double_ref.npz'))
+    FFTWDATA_SINGLE = np.load(join(fftpack_test_dir, 'fftw_single_ref.npz'))
+    FFTWDATA_SIZES = FFTWDATA_DOUBLE['sizes']
+    assert len(FFTWDATA_SIZES) == FFTWDATA_COUNT
+
+    if is_longdouble_binary_compatible():
+        FFTWDATA_LONGDOUBLE = np.load(
+            join(fftpack_test_dir, 'fftw_longdouble_ref.npz'))
+    else:
+        FFTWDATA_LONGDOUBLE = {k: v.astype(np.longfloat)
+                               for k,v in FFTWDATA_DOUBLE.items()}
+
+    ref = {
+        'FFTWDATA_LONGDOUBLE': FFTWDATA_LONGDOUBLE,
+        'FFTWDATA_DOUBLE': FFTWDATA_DOUBLE,
+        'FFTWDATA_SINGLE': FFTWDATA_SINGLE,
+        'FFTWDATA_SIZES': FFTWDATA_SIZES,
+        'X': X,
+        'Y': Y
+    }
+
+    globals()['__reference_data'] = ref
+    return ref
+
+
+@pytest.fixture(params=range(FFTWDATA_COUNT))
+def fftwdata_size(request):
+    return get_reference_data()['FFTWDATA_SIZES'][request.param]
+
+@pytest.fixture(params=range(MDATA_COUNT))
+def mdata_x(request):
+    return get_reference_data()['X'][request.param]
+
+
+@pytest.fixture(params=range(MDATA_COUNT))
+def mdata_xy(request):
+    ref = get_reference_data()
+    y = ref['Y'][request.param]
+    x = ref['X'][request.param]
+    return x, y
+
+
+def fftw_dct_ref(type, size, dt):
+    x = np.linspace(0, size-1, size).astype(dt)
+    dt = np.result_type(np.float32, dt)
+    if dt == np.double:
+        data = get_reference_data()['FFTWDATA_DOUBLE']
+    elif dt == np.float32:
+        data = get_reference_data()['FFTWDATA_SINGLE']
+    elif dt == np.longfloat:
+        data = get_reference_data()['FFTWDATA_LONGDOUBLE']
+    else:
+        raise ValueError()
+    y = (data['dct_%d_%d' % (type, size)]).astype(dt)
+    return x, y, dt
+
+
+def fftw_dst_ref(type, size, dt):
+    x = np.linspace(0, size-1, size).astype(dt)
+    dt = np.result_type(np.float32, dt)
+    if dt == np.double:
+        data = get_reference_data()['FFTWDATA_DOUBLE']
+    elif dt == np.float32:
+        data = get_reference_data()['FFTWDATA_SINGLE']
+    elif dt == np.longfloat:
+        data = get_reference_data()['FFTWDATA_LONGDOUBLE']
+    else:
+        raise ValueError()
+    y = (data['dst_%d_%d' % (type, size)]).astype(dt)
+    return x, y, dt
+
+
+def ref_2d(func, x, **kwargs):
+    """Calculate 2-D reference data from a 1d transform"""
+    x = np.array(x, copy=True)
+    for row in range(x.shape[0]):
+        x[row, :] = func(x[row, :], **kwargs)
+    for col in range(x.shape[1]):
+        x[:, col] = func(x[:, col], **kwargs)
+    return x
+
+
+def naive_dct1(x, norm=None):
+    """Calculate textbook definition version of DCT-I."""
+    x = np.array(x, copy=True)
+    N = len(x)
+    M = N-1
+    y = np.zeros(N)
+    m0, m = 1, 2
+    if norm == 'ortho':
+        m0 = np.sqrt(1.0/M)
+        m = np.sqrt(2.0/M)
+    for k in range(N):
+        for n in range(1, N-1):
+            y[k] += m*x[n]*np.cos(np.pi*n*k/M)
+        y[k] += m0 * x[0]
+        y[k] += m0 * x[N-1] * (1 if k % 2 == 0 else -1)
+    if norm == 'ortho':
+        y[0] *= 1/np.sqrt(2)
+        y[N-1] *= 1/np.sqrt(2)
+    return y
+
+
+def naive_dst1(x, norm=None):
+    """Calculate textbook definition version of DST-I."""
+    x = np.array(x, copy=True)
+    N = len(x)
+    M = N+1
+    y = np.zeros(N)
+    for k in range(N):
+        for n in range(N):
+            y[k] += 2*x[n]*np.sin(np.pi*(n+1.0)*(k+1.0)/M)
+    if norm == 'ortho':
+        y *= np.sqrt(0.5/M)
+    return y
+
+
+def naive_dct4(x, norm=None):
+    """Calculate textbook definition version of DCT-IV."""
+    x = np.array(x, copy=True)
+    N = len(x)
+    y = np.zeros(N)
+    for k in range(N):
+        for n in range(N):
+            y[k] += x[n]*np.cos(np.pi*(n+0.5)*(k+0.5)/(N))
+    if norm == 'ortho':
+        y *= np.sqrt(2.0/N)
+    else:
+        y *= 2
+    return y
+
+
+def naive_dst4(x, norm=None):
+    """Calculate textbook definition version of DST-IV."""
+    x = np.array(x, copy=True)
+    N = len(x)
+    y = np.zeros(N)
+    for k in range(N):
+        for n in range(N):
+            y[k] += x[n]*np.sin(np.pi*(n+0.5)*(k+0.5)/(N))
+    if norm == 'ortho':
+        y *= np.sqrt(2.0/N)
+    else:
+        y *= 2
+    return y
+
+
+@pytest.mark.parametrize('dtype', [np.complex64, np.complex128, np.longcomplex])
+@pytest.mark.parametrize('transform', [dct, dst, idct, idst])
+def test_complex(transform, dtype):
+    y = transform(1j*np.arange(5, dtype=dtype))
+    x = 1j*transform(np.arange(5))
+    assert_array_almost_equal(x, y)
+
+
+# map (tranform, dtype, type) -> decimal
+dec_map = {
+    # DCT
+    (dct, np.double, 1): 13,
+    (dct, np.float32, 1): 6,
+
+    (dct, np.double, 2): 14,
+    (dct, np.float32, 2): 5,
+
+    (dct, np.double, 3): 14,
+    (dct, np.float32, 3): 5,
+
+    (dct, np.double, 4): 13,
+    (dct, np.float32, 4): 6,
+
+    # IDCT
+    (idct, np.double, 1): 14,
+    (idct, np.float32, 1): 6,
+
+    (idct, np.double, 2): 14,
+    (idct, np.float32, 2): 5,
+
+    (idct, np.double, 3): 14,
+    (idct, np.float32, 3): 5,
+
+    (idct, np.double, 4): 14,
+    (idct, np.float32, 4): 6,
+
+    # DST
+    (dst, np.double, 1): 13,
+    (dst, np.float32, 1): 6,
+
+    (dst, np.double, 2): 14,
+    (dst, np.float32, 2): 6,
+
+    (dst, np.double, 3): 14,
+    (dst, np.float32, 3): 7,
+
+    (dst, np.double, 4): 13,
+    (dst, np.float32, 4): 6,
+
+    # IDST
+    (idst, np.double, 1): 14,
+    (idst, np.float32, 1): 6,
+
+    (idst, np.double, 2): 14,
+    (idst, np.float32, 2): 6,
+
+    (idst, np.double, 3): 14,
+    (idst, np.float32, 3): 6,
+
+    (idst, np.double, 4): 14,
+    (idst, np.float32, 4): 6,
+}
+
+for k,v in dec_map.copy().items():
+    if k[1] == np.double:
+        dec_map[(k[0], np.longdouble, k[2])] = v
+    elif k[1] == np.float32:
+        dec_map[(k[0], int, k[2])] = v
+
+
+@pytest.mark.parametrize('rdt', [np.longfloat, np.double, np.float32, int])
+@pytest.mark.parametrize('type', [1, 2, 3, 4])
+class TestDCT:
+    def test_definition(self, rdt, type, fftwdata_size):
+        x, yr, dt = fftw_dct_ref(type, fftwdata_size, rdt)
+        y = dct(x, type=type)
+        assert_equal(y.dtype, dt)
+        dec = dec_map[(dct, rdt, type)]
+        assert_allclose(y, yr, rtol=0., atol=np.max(yr)*10**(-dec))
+
+    @pytest.mark.parametrize('size', [7, 8, 9, 16, 32, 64])
+    def test_axis(self, rdt, type, size):
+        nt = 2
+        dec = dec_map[(dct, rdt, type)]
+        x = np.random.randn(nt, size)
+        y = dct(x, type=type)
+        for j in range(nt):
+            assert_array_almost_equal(y[j], dct(x[j], type=type),
+                                      decimal=dec)
+
+        x = x.T
+        y = dct(x, axis=0, type=type)
+        for j in range(nt):
+            assert_array_almost_equal(y[:,j], dct(x[:,j], type=type),
+                                      decimal=dec)
+
+
+@pytest.mark.parametrize('rdt', [np.longfloat, np.double, np.float32, int])
+def test_dct1_definition_ortho(rdt, mdata_x):
+    # Test orthornomal mode.
+    dec = dec_map[(dct, rdt, 1)]
+    x = np.array(mdata_x, dtype=rdt)
+    dt = np.result_type(np.float32, rdt)
+    y = dct(x, norm='ortho', type=1)
+    y2 = naive_dct1(x, norm='ortho')
+    assert_equal(y.dtype, dt)
+    assert_allclose(y, y2, rtol=0., atol=np.max(y2)*10**(-dec))
+
+
+@pytest.mark.parametrize('rdt', [np.longfloat, np.double, np.float32, int])
+def test_dct2_definition_matlab(mdata_xy, rdt):
+    # Test correspondence with matlab (orthornomal mode).
+    dt = np.result_type(np.float32, rdt)
+    x = np.array(mdata_xy[0], dtype=dt)
+
+    yr = mdata_xy[1]
+    y = dct(x, norm="ortho", type=2)
+    dec = dec_map[(dct, rdt, 2)]
+    assert_equal(y.dtype, dt)
+    assert_array_almost_equal(y, yr, decimal=dec)
+
+
+@pytest.mark.parametrize('rdt', [np.longfloat, np.double, np.float32, int])
+def test_dct3_definition_ortho(mdata_x, rdt):
+    # Test orthornomal mode.
+    x = np.array(mdata_x, dtype=rdt)
+    dt = np.result_type(np.float32, rdt)
+    y = dct(x, norm='ortho', type=2)
+    xi = dct(y, norm="ortho", type=3)
+    dec = dec_map[(dct, rdt, 3)]
+    assert_equal(xi.dtype, dt)
+    assert_array_almost_equal(xi, x, decimal=dec)
+
+
+@pytest.mark.parametrize('rdt', [np.longfloat, np.double, np.float32, int])
+def test_dct4_definition_ortho(mdata_x, rdt):
+    # Test orthornomal mode.
+    x = np.array(mdata_x, dtype=rdt)
+    dt = np.result_type(np.float32, rdt)
+    y = dct(x, norm='ortho', type=4)
+    y2 = naive_dct4(x, norm='ortho')
+    dec = dec_map[(dct, rdt, 4)]
+    assert_equal(y.dtype, dt)
+    assert_allclose(y, y2, rtol=0., atol=np.max(y2)*10**(-dec))
+
+
+@pytest.mark.parametrize('rdt', [np.longfloat, np.double, np.float32, int])
+@pytest.mark.parametrize('type', [1, 2, 3, 4])
+def test_idct_definition(fftwdata_size, rdt, type):
+    xr, yr, dt = fftw_dct_ref(type, fftwdata_size, rdt)
+    x = idct(yr, type=type)
+    dec = dec_map[(idct, rdt, type)]
+    assert_equal(x.dtype, dt)
+    assert_allclose(x, xr, rtol=0., atol=np.max(xr)*10**(-dec))
+
+
+@pytest.mark.parametrize('rdt', [np.longfloat, np.double, np.float32, int])
+@pytest.mark.parametrize('type', [1, 2, 3, 4])
+def test_definition(fftwdata_size, rdt, type):
+    xr, yr, dt = fftw_dst_ref(type, fftwdata_size, rdt)
+    y = dst(xr, type=type)
+    dec = dec_map[(dst, rdt, type)]
+    assert_equal(y.dtype, dt)
+    assert_allclose(y, yr, rtol=0., atol=np.max(yr)*10**(-dec))
+
+
+@pytest.mark.parametrize('rdt', [np.longfloat, np.double, np.float32, int])
+def test_dst1_definition_ortho(rdt, mdata_x):
+    # Test orthornomal mode.
+    dec = dec_map[(dst, rdt, 1)]
+    x = np.array(mdata_x, dtype=rdt)
+    dt = np.result_type(np.float32, rdt)
+    y = dst(x, norm='ortho', type=1)
+    y2 = naive_dst1(x, norm='ortho')
+    assert_equal(y.dtype, dt)
+    assert_allclose(y, y2, rtol=0., atol=np.max(y2)*10**(-dec))
+
+
+@pytest.mark.parametrize('rdt', [np.longfloat, np.double, np.float32, int])
+def test_dst4_definition_ortho(rdt, mdata_x):
+    # Test orthornomal mode.
+    dec = dec_map[(dst, rdt, 4)]
+    x = np.array(mdata_x, dtype=rdt)
+    dt = np.result_type(np.float32, rdt)
+    y = dst(x, norm='ortho', type=4)
+    y2 = naive_dst4(x, norm='ortho')
+    assert_equal(y.dtype, dt)
+    assert_array_almost_equal(y, y2, decimal=dec)
+
+
+@pytest.mark.parametrize('rdt', [np.longfloat, np.double, np.float32, int])
+@pytest.mark.parametrize('type', [1, 2, 3, 4])
+def test_idst_definition(fftwdata_size, rdt, type):
+    xr, yr, dt = fftw_dst_ref(type, fftwdata_size, rdt)
+    x = idst(yr, type=type)
+    dec = dec_map[(idst, rdt, type)]
+    assert_equal(x.dtype, dt)
+    assert_allclose(x, xr, rtol=0., atol=np.max(xr)*10**(-dec))
+
+
+@pytest.mark.parametrize('routine', [dct, dst, idct, idst])
+@pytest.mark.parametrize('dtype', [np.float32, np.float64, np.longfloat])
+@pytest.mark.parametrize('shape, axis', [
+    ((16,), -1), ((16, 2), 0), ((2, 16), 1)
+])
+@pytest.mark.parametrize('type', [1, 2, 3, 4])
+@pytest.mark.parametrize('overwrite_x', [True, False])
+@pytest.mark.parametrize('norm', [None, 'ortho'])
+def test_overwrite(routine, dtype, shape, axis, type, norm, overwrite_x):
+    # Check input overwrite behavior
+    np.random.seed(1234)
+    if np.issubdtype(dtype, np.complexfloating):
+        x = np.random.randn(*shape) + 1j*np.random.randn(*shape)
+    else:
+        x = np.random.randn(*shape)
+    x = x.astype(dtype)
+    x2 = x.copy()
+    routine(x2, type, None, axis, norm, overwrite_x=overwrite_x)
+
+    sig = "%s(%s%r, %r, axis=%r, overwrite_x=%r)" % (
+        routine.__name__, x.dtype, x.shape, None, axis, overwrite_x)
+    if not overwrite_x:
+        assert_equal(x2, x, err_msg="spurious overwrite in %s" % sig)
+
+
+class Test_DCTN_IDCTN(object):
+    dec = 14
+    dct_type = [1, 2, 3, 4]
+    norms = [None, 'ortho']
+    rstate = np.random.RandomState(1234)
+    shape = (32, 16)
+    data = rstate.randn(*shape)
+
+    @pytest.mark.parametrize('fforward,finverse', [(dctn, idctn),
+                                                   (dstn, idstn)])
+    @pytest.mark.parametrize('axes', [None,
+                                      1, (1,), [1],
+                                      0, (0,), [0],
+                                      (0, 1), [0, 1],
+                                      (-2, -1), [-2, -1]])
+    @pytest.mark.parametrize('dct_type', dct_type)
+    @pytest.mark.parametrize('norm', ['ortho'])
+    def test_axes_round_trip(self, fforward, finverse, axes, dct_type, norm):
+        tmp = fforward(self.data, type=dct_type, axes=axes, norm=norm)
+        tmp = finverse(tmp, type=dct_type, axes=axes, norm=norm)
+        assert_array_almost_equal(self.data, tmp, decimal=12)
+
+    @pytest.mark.parametrize('funcn,func', [(dctn, dct), (dstn, dst)])
+    @pytest.mark.parametrize('dct_type', dct_type)
+    @pytest.mark.parametrize('norm', norms)
+    def test_dctn_vs_2d_reference(self, funcn, func, dct_type, norm):
+        y1 = funcn(self.data, type=dct_type, axes=None, norm=norm)
+        y2 = ref_2d(func, self.data, type=dct_type, norm=norm)
+        assert_array_almost_equal(y1, y2, decimal=11)
+
+    @pytest.mark.parametrize('funcn,func', [(idctn, idct), (idstn, idst)])
+    @pytest.mark.parametrize('dct_type', dct_type)
+    @pytest.mark.parametrize('norm', [None, 'ortho'])
+    def test_idctn_vs_2d_reference(self, funcn, func, dct_type, norm):
+        fdata = dctn(self.data, type=dct_type, norm=norm)
+        y1 = funcn(fdata, type=dct_type, norm=norm)
+        y2 = ref_2d(func, fdata, type=dct_type, norm=norm)
+        assert_array_almost_equal(y1, y2, decimal=11)
+
+    @pytest.mark.parametrize('fforward,finverse', [(dctn, idctn),
+                                                   (dstn, idstn)])
+    def test_axes_and_shape(self, fforward, finverse):
+        with assert_raises(ValueError,
+                           match="when given, axes and shape arguments"
+                           " have to be of the same length"):
+            fforward(self.data, s=self.data.shape[0], axes=(0, 1))
+
+        with assert_raises(ValueError,
+                           match="when given, axes and shape arguments"
+                           " have to be of the same length"):
+            fforward(self.data, s=self.data.shape, axes=0)
+
+    @pytest.mark.parametrize('fforward', [dctn, dstn])
+    def test_shape(self, fforward):
+        tmp = fforward(self.data, s=(128, 128), axes=None)
+        assert_equal(tmp.shape, (128, 128))
+
+    @pytest.mark.parametrize('fforward,finverse', [(dctn, idctn),
+                                                   (dstn, idstn)])
+    @pytest.mark.parametrize('axes', [1, (1,), [1],
+                                      0, (0,), [0]])
+    def test_shape_is_none_with_axes(self, fforward, finverse, axes):
+        tmp = fforward(self.data, s=None, axes=axes, norm='ortho')
+        tmp = finverse(tmp, s=None, axes=axes, norm='ortho')
+        assert_array_almost_equal(self.data, tmp, decimal=self.dec)
+
+
+@pytest.mark.parametrize('func', [dct, dctn, idct, idctn,
+                                  dst, dstn, idst, idstn])
+def test_swapped_byte_order(func):
+    rng = np.random.RandomState(1234)
+    x = rng.rand(10)
+    swapped_dt = x.dtype.newbyteorder('S')
+    assert_allclose(func(x.astype(swapped_dt)), func(x))