Python numpy.frexp方法代码示例

# 需要导入模块: import numpy [as 别名]
# 或者: from numpy import frexp [as 别名]
def test_failing_out_wrap(self):

        singleton = np.array([1.0])

        class Ok(np.ndarray):
            def __array_wrap__(self, obj):
                return singleton

        class Bad(np.ndarray):
            def __array_wrap__(self, obj):
                raise RuntimeError

        ok = np.empty(1).view(Ok)
        bad = np.empty(1).view(Bad)

        # double-free (segfault) of "ok" if "bad" raises an exception
        for i in range(10):
            assert_raises(RuntimeError, ncu.frexp, 1, ok, bad) 

# 需要导入模块: import numpy [as 别名]
# 或者: from numpy import frexp [as 别名]
def robust_outer_product(vec_1, vec_2):
    """
    Calculates a 'robust' outer product of two vectors that may or may not
    contain very small values.

    Parameters
    ----------
    vec_1 : 1D ndarray
    vec_2 : 1D ndarray

    Returns
    -------
    outer_prod : 2D ndarray. The outer product of vec_1 and vec_2
    """
    mantissa_1, exponents_1 = np.frexp(vec_1)
    mantissa_2, exponents_2 = np.frexp(vec_2)
    new_mantissas = mantissa_1[None, :] * mantissa_2[:, None]
    new_exponents = exponents_1[None, :] + exponents_2[:, None]
    return new_mantissas * np.exp2(new_exponents) 

# 需要导入模块: import numpy [as 别名]
# 或者: from numpy import frexp [as 别名]
def testFrexp(self):
        t1 = ones((3, 4, 5), chunk_size=2)
        t2 = empty((3, 4, 5), dtype=np.float_, chunk_size=2)
        op_type = type(t1.op)

        o1, o2 = frexp(t1)

        self.assertIs(o1.op, o2.op)
        self.assertNotEqual(o1.dtype, o2.dtype)

        o1, o2 = frexp(t1, t1)

        self.assertIs(o1, t1)
        self.assertIsNot(o1.inputs[0], t1)
        self.assertIsInstance(o1.inputs[0].op, op_type)
        self.assertIsNot(o2.inputs[0], t1)

        o1, o2 = frexp(t1, t2, where=t1 > 0)

        op_type = type(t2.op)
        self.assertIs(o1, t2)
        self.assertIsNot(o1.inputs[0], t1)
        self.assertIsInstance(o1.inputs[0].op, op_type)
        self.assertIsNot(o2.inputs[0], t1) 

# 需要导入模块: import numpy [as 别名]
# 或者: from numpy import frexp [as 别名]
def clear_fuss(ar, fuss_binary_bits=7):
    """Clears trailing `fuss_binary_bits` of mantissa of a floating number"""
    x = np.asanyarray(ar)
    if np.iscomplexobj(x):
        return clear_fuss(x.real) + 1j * clear_fuss(x.imag)

    significant_binary_bits = np.finfo(x.dtype).nmant
    x_mant, x_exp = np.frexp(x)
    f = 2.0**(significant_binary_bits - fuss_binary_bits)
    x_mant *= f
    np.rint(x_mant, out=x_mant)
    x_mant /= f

    return np.ldexp(x_mant, x_exp)


# XXX: This function should be available through numpy.testing 

# 需要导入模块: import numpy [as 别名]
# 或者: from numpy import frexp [as 别名]
def test_ufunc_two_outputs(self):
        mantissa, exponent = np.frexp(2 ** -3)
        expected = (ArrayLike(mantissa), ArrayLike(exponent))
        _assert_equal_type_and_value(
            np.frexp(ArrayLike(2 ** -3)), expected)
        _assert_equal_type_and_value(
            np.frexp(ArrayLike(np.array(2 ** -3))), expected) 

# 需要导入模块: import numpy [as 别名]
# 或者: from numpy import frexp [as 别名]
def test_doc(self):
        # don't bother checking the long list of kwargs, which are likely to
        # change
        assert_(ncu.add.__doc__.startswith(
            "add(x1, x2, /, out=None, *, where=True"))
        assert_(ncu.frexp.__doc__.startswith(
            "frexp(x[, out1, out2], / [, out=(None, None)], *, where=True")) 

# 需要导入模块: import numpy [as 别名]
# 或者: from numpy import frexp [as 别名]
def execute(cls, ctx, op):
        inputs, device_id, xp = as_same_device(
            [ctx[c.key] for c in op.inputs], device=op.device, ret_extra=True)

        with device(device_id):
            kw = {'casting': op.casting}

            inputs_iter = iter(inputs)
            input = next(inputs_iter)
            if op.out1 is not None:
                out1 = next(inputs_iter)
            else:
                out1 = None
            if op.out2 is not None:
                out2 = next(inputs_iter)
            else:
                out2 = None
            if op.where is not None:
                where = kw['where'] = next(inputs_iter)
            else:
                where = None
            kw['order'] = op.order

            try:
                args = [input]
                if out1 is not None:
                    args.append(out1)
                if out2 is not None:
                    args.append(out2)
                mantissa, exponent = xp.frexp(*args, **kw)
            except TypeError:
                if where is None:
                    raise
                mantissa, exponent = xp.frexp(input)
                mantissa, exponent = xp.where(where, mantissa, out1), xp.where(where, exponent, out2)

            for c, res in zip(op.outputs, (mantissa, exponent)):
                ctx[c.key] = res 

# 需要导入模块: import numpy [as 别名]
# 或者: from numpy import frexp [as 别名]
def testFrexpExecution(self):
        data1 = np.random.random((5, 9, 4))

        arr1 = tensor(data1.copy(), chunk_size=3)

        o1, o2 = frexp(arr1)
        o = o1 + o2

        res = self.executor.execute_tensor(o, concat=True)[0]
        expected = sum(np.frexp(data1))
        self.assertTrue(np.allclose(res, expected))

        arr1 = tensor(data1.copy(), chunk_size=3)
        o1 = zeros(data1.shape, chunk_size=3)
        o2 = zeros(data1.shape, dtype='i8', chunk_size=3)
        frexp(arr1, o1, o2)
        o = o1 + o2

        res = self.executor.execute_tensor(o, concat=True)[0]
        expected = sum(np.frexp(data1))
        self.assertTrue(np.allclose(res, expected))

        data1 = sps.random(5, 9, density=.1)

        arr1 = tensor(data1.copy(), chunk_size=3)

        o1, o2 = frexp(arr1)
        o = o1 + o2

        res = self.executor.execute_tensor(o, concat=True)[0]
        expected = sum(np.frexp(data1.toarray()))
        np.testing.assert_equal(res.toarray(), expected) 

# 需要导入模块: import numpy [as 别名]
# 或者: from numpy import frexp [as 别名]
def testFrexpOrderExecution(self):
        data1 = np.random.random((5, 9))
        t = tensor(data1, chunk_size=3)

        o1, o2 = frexp(t, order='F')
        res1, res2 = self.executor.execute_tileables([o1, o2])
        expected1, expected2 = np.frexp(data1, order='F')
        np.testing.assert_allclose(res1, expected1)
        self.assertTrue(res1.flags['F_CONTIGUOUS'])
        self.assertFalse(res1.flags['C_CONTIGUOUS'])
        np.testing.assert_allclose(res2, expected2)
        self.assertTrue(res2.flags['F_CONTIGUOUS'])
        self.assertFalse(res2.flags['C_CONTIGUOUS']) 

# 需要导入模块: import numpy [as 别名]
# 或者: from numpy import frexp [as 别名]
def test_ufunc_override_out(self):
        # 2016-01-29: NUMPY_UFUNC_DISABLED
        return

        class A(object):
            def __numpy_ufunc__(self, ufunc, method, pos, inputs, **kwargs):
                return kwargs

        class B(object):
            def __numpy_ufunc__(self, ufunc, method, pos, inputs, **kwargs):
                return kwargs

        a = A()
        b = B()
        res0 = np.multiply(a, b, 'out_arg')
        res1 = np.multiply(a, b, out='out_arg')
        res2 = np.multiply(2, b, 'out_arg')
        res3 = np.multiply(3, b, out='out_arg')
        res4 = np.multiply(a, 4, 'out_arg')
        res5 = np.multiply(a, 5, out='out_arg')

        assert_equal(res0['out'], 'out_arg')
        assert_equal(res1['out'], 'out_arg')
        assert_equal(res2['out'], 'out_arg')
        assert_equal(res3['out'], 'out_arg')
        assert_equal(res4['out'], 'out_arg')
        assert_equal(res5['out'], 'out_arg')

        # ufuncs with multiple output modf and frexp.
        res6 = np.modf(a, 'out0', 'out1')
        res7 = np.frexp(a, 'out0', 'out1')
        assert_equal(res6['out'][0], 'out0')
        assert_equal(res6['out'][1], 'out1')
        assert_equal(res7['out'][0], 'out0')
        assert_equal(res7['out'][1], 'out1') 

# 需要导入模块: import numpy [as 别名]
# 或者: from numpy import frexp [as 别名]
def radiance_writer(out_path, image):
    with open(out_path, "wb") as f:
        f.write(b"#?RADIANCE\n# Made with Python & Numpy\nFORMAT=32-bit_rle_rgbe\n\n")
        f.write(b"-Y %d +X %d\n" %(image.shape[0], image.shape[1]))

        brightest = np.maximum(np.maximum(image[...,0], image[...,1]), image[...,2])
        mantissa = np.zeros_like(brightest)
        exponent = np.zeros_like(brightest)
        np.frexp(brightest, mantissa, exponent)
        scaled_mantissa = mantissa * 255.0 / brightest
        rgbe = np.zeros((image.shape[0], image.shape[1], 4), dtype=np.uint8)
        rgbe[...,0:3] = np.around(image[...,0:3] * scaled_mantissa[...,None])
        rgbe[...,3] = np.around(exponent + 128)

        rgbe.flatten().tofile(f) 

# 需要导入模块: import numpy [as 别名]
# 或者: from numpy import frexp [as 别名]
def test_frexp(self, dtype):
        numpy_a = numpy.array([-300, -20, -10, -1, 0, 1, 10, 20, 300],
                              dtype=dtype)
        numpy_b, numpy_c = numpy.frexp(numpy_a)

        cupy_a = cupy.array(numpy_a)
        cupy_b, cupy_c = cupy.frexp(cupy_a)

        testing.assert_array_equal(cupy_b, numpy_b)
        testing.assert_array_equal(cupy_c, numpy_c) 

# 需要导入模块: import numpy [as 别名]
# 或者: from numpy import frexp [as 别名]
def pow_next_log_of_2_no_round(value, bound_shift, shift_max_shift=4):
    mul, shift = np.frexp(np.abs(value))    # value = mul(0~1)*(1 << shift)
    ret = bound_shift - 1 - shift           # shift to full bound_shift
    mul = np.sign(value) * mul * np.power(2, bound_shift - 1)   # scale mul
    # value = mul>>ret
    return ret, mul