From e9e267ef711261f20528d443f38eb7b9e991057c Mon Sep 17 00:00:00 2001
From: reminisce <wujun.nju@gmail.com>
Date: Sat, 14 Sep 2019 09:33:08 -0700
Subject: [PATCH] Fix remaining errors reported by D2L (#16157)

* Fix

* Fix ssd

* Add test for np.empty

* Add np.linalg.norm

* Fix indexing bug

* Improve doc
---
 python/mxnet/_numpy_op_doc.py               | 353 +++++++++++++++++++-
 python/mxnet/gluon/loss.py                  |  10 +-
 python/mxnet/ndarray/numpy/linalg.py        |  48 ++-
 python/mxnet/numpy/linalg.py                |  42 ++-
 python/mxnet/numpy/multiarray.py            | 102 ++++--
 python/mxnet/symbol/numpy/_symbol.py        |  20 +-
 python/mxnet/symbol/numpy/linalg.py         |  48 ++-
 tests/python/unittest/test_numpy_gluon.py   |  38 ++-
 tests/python/unittest/test_numpy_ndarray.py |  71 +++-
 tests/python/unittest/test_numpy_op.py      |  81 ++++-
 10 files changed, 751 insertions(+), 62 deletions(-)

diff --git a/python/mxnet/_numpy_op_doc.py b/python/mxnet/_numpy_op_doc.py
index 4e5ea74c2771..c95752a00cb6 100644
--- a/python/mxnet/_numpy_op_doc.py
+++ b/python/mxnet/_numpy_op_doc.py
@@ -21,7 +21,10 @@
 
 
 def _np_ones_like(a):
-    """Return an array of ones with the same shape and type as a given array.
+    """
+    ones_like(a)
+
+    Return an array of ones with the same shape and type as a given array.
 
     Parameters
     ----------
@@ -38,7 +41,10 @@ def _np_ones_like(a):
 
 
 def _np_zeros_like(a):
-    """Return an array of zeros with the same shape and type as a given array.
+    """
+    zeros_like(a)
+
+    Return an array of zeros with the same shape and type as a given array.
 
     Parameters
     ----------
@@ -55,7 +61,10 @@ def _np_zeros_like(a):
 
 
 def _np_cumsum(a, axis=None, dtype=None, out=None):
-    """Return the cumulative sum of the elements along a given axis.
+    """
+    cumsum(a, axis=None, dtype=None, out=None)
+
+    Return the cumulative sum of the elements along a given axis.
 
     Parameters
     ----------
@@ -103,3 +112,341 @@ def _np_cumsum(a, axis=None, dtype=None, out=None):
 
     """
     pass
+
+
+def _np_repeat(a, repeats, axis=None):
+    """
+    repeat(a, repeats, axis=None)
+
+    Repeat elements of an array.
+
+    Parameters
+    ----------
+    a : ndarray
+        Input array.
+    repeats : int
+        The number of repetitions for each element.
+    axis : int, optional
+        The axis along which to repeat values.  By default, use the
+        flattened input array, and return a flat output array.
+
+    Returns
+    -------
+    repeated_array : ndarray
+        Output array which has the same shape as `a`, except along
+        the given axis.
+
+    Notes
+    -----
+    Unlike the official NumPy ``repeat`` operator, this operator currently
+    does not support array of ints for the parameter `repeats`.
+
+    Examples
+    --------
+    >>> x = np.arange(4).reshape(2, 2)
+    >>> x
+    array([[0., 1.],
+           [2., 3.]])
+    >>> np.repeat(x, repeats=3)
+    array([0., 0., 0., 1., 1., 1., 2., 2., 2., 3., 3., 3.])
+    >>> np.repeat(x, repeats=3, axis=0)
+    array([[0., 1.],
+           [0., 1.],
+           [0., 1.],
+           [2., 3.],
+           [2., 3.],
+           [2., 3.]])
+    >>> np.repeat(x, repeats=3, axis=1)
+    array([[0., 0., 0., 1., 1., 1.],
+           [2., 2., 2., 3., 3., 3.]])
+    """
+    pass
+
+
+def _np_transpose(a, axes=None):
+    """
+    transpose(a, axes=None)
+
+    Permute the dimensions of an array.
+
+    Parameters
+    ----------
+    a : ndarray
+        Input array.
+    axes : list of ints, optional
+        By default, reverse the dimensions,
+        otherwise permute the axes according to the values given.
+
+    Returns
+    -------
+    p : ndarray
+        a with its axes permuted.
+
+    Notes
+    -----
+    This function differs from the original `numpy.transpose
+    <https://docs.scipy.org/doc/numpy/reference/generated/numpy.transpose.html>`_ in
+    the following way(s):
+
+    - only ndarray is accepted as valid input, python iterables are not supported
+    - the operator always returns an `ndarray` that does not share the memory with the input
+
+    Examples
+    --------
+    >>> x = np.arange(4).reshape((2,2))
+    >>> x
+    array([[0., 1.],
+           [2., 3.]])
+    >>> np.transpose(x)
+    array([[0., 2.],
+           [1., 3.]])
+    >>> x = np.ones((1, 2, 3))
+    >>> np.transpose(x, (1, 0, 2)).shape
+    (2, 1, 3)
+    """
+    pass
+
+
+def _np_dot(a, b, out=None):
+    """dot(a, b, out=None)
+
+    Dot product of two arrays. Specifically,
+
+    - If both `a` and `b` are 1-D arrays, it is inner product of vectors
+
+    - If both `a` and `b` are 2-D arrays, it is matrix multiplication,
+
+    - If either `a` or `b` is 0-D (scalar), it is equivalent to :func:`multiply`
+      and using ``np.multiply(a, b)`` or ``a * b`` is preferred.
+
+    - If `a` is an N-D array and `b` is a 1-D array, it is a sum product over
+      the last axis of `a` and `b`.
+
+    - If `a` is an N-D array and `b` is a 2-D array, it is a
+      sum product over the last axis of `a` and the second-to-last axis of `b`::
+
+        dot(a, b)[i,j,k] = sum(a[i,j,:] * b[:,k])
+
+    Parameters
+    ----------
+    a : ndarray
+        First argument.
+    b : ndarray
+        Second argument.
+
+    out : ndarray, optional
+        Output argument. It must have the same shape and type as the expected output.
+
+    Returns
+    -------
+    output : ndarray
+        Returns the dot product of `a` and `b`.  If `a` and `b` are both
+        scalars or both 1-D arrays then a scalar is returned; otherwise
+        an array is returned.
+        If `out` is given, then it is returned
+
+    Examples
+    --------
+    >>> a = np.array(3)
+    >>> b = np.array(4)
+    >>> np.dot(a, b)
+    array(12.)
+
+    For 2-D arrays it is the matrix product:
+
+    >>> a = np.array([[1, 0], [0, 1]])
+    >>> b = np.array([[4, 1], [2, 2]])
+    >>> np.dot(a, b)
+    array([[4., 1.],
+           [2., 2.]])
+
+    >>> a = np.arange(3*4*5*6).reshape((3,4,5,6))
+    >>> b = np.arange(5*6)[::-1].reshape((6,5))
+    >>> np.dot(a, b)[2,3,2,2]
+    array(29884.)
+    >>> np.sum(a[2,3,2,:] * b[:,2])
+    array(29884.)
+    """
+    pass
+
+
+def _np_sum(a, axis=0, dtype=None, keepdims=None, initial=None, out=None):
+    r"""
+    sum(a, axis=None, dtype=None, keepdims=_Null, initial=_Null, out=None)
+
+    Sum of array elements over a given axis.
+
+    Parameters
+    ----------
+    a : ndarray
+        Input data.
+    axis : None or int, optional
+        Axis or axes along which a sum is performed.  The default,
+        axis=None, will sum all of the elements of the input array.  If
+        axis is negative it counts from the last to the first axis.
+    dtype : dtype, optional
+        The type of the returned array and of the accumulator in which the
+        elements are summed. The default type is float32.
+    keepdims : bool, optional
+        If this is set to True, the axes which are reduced are left
+        in the result as dimensions with size one. With this option,
+        the result will broadcast correctly against the input array.
+
+        If the default value is passed, then `keepdims` will not be
+        passed through to the `sum` method of sub-classes of
+        `ndarray`, however any non-default value will be.  If the
+        sub-classes `sum` method does not implement `keepdims` any
+        exceptions will be raised.
+    initial: Currently only supports None as input, optional
+        Starting value for the sum.
+        Currently not implemented. Please use ``None`` as input or skip this argument.
+    out : ndarray or None, optional
+        Alternative output array in which to place the result. It must have
+        the same shape and dtype as the expected output.
+
+    Returns
+    -------
+    sum_along_axis : ndarray
+        An ndarray with the same shape as `a`, with the specified
+        axis removed. If an output array is specified, a reference to
+        `out` is returned.
+
+    Notes
+    -----
+    - Input type does not support Python native iterables.
+    - "out" param: cannot perform auto type change. out ndarray's dtype must be the same as the expected output.
+    - "initial" param is not supported yet. Please use None as input.
+    - Arithmetic is modular when using integer types, and no error is raised on overflow.
+    - The sum of an empty array is the neutral element 0:
+
+    >>> a = np.empty(1)
+    >>> np.sum(a)
+    array(0.)
+
+    This function differs from the original `numpy.sum
+    <https://docs.scipy.org/doc/numpy/reference/generated/numpy.sum.html>`_ in
+    the following aspects:
+
+    - Input type does not support Python native iterables(list, tuple, ...).
+    - "out" param: cannot perform auto type cast. out ndarray's dtype must be the same as the expected output.
+    - "initial" param is not supported yet. Please use ``None`` as input or skip it.
+
+    Examples
+    --------
+    >>> a = np.array([0.5, 1.5])
+    >>> np.sum(a)
+    array(2.)
+    >>> a = np.array([0.5, 0.7, 0.2, 1.5])
+    >>> np.sum(a, dtype=np.int32)
+    array(2, dtype=int32)
+    >>> a = np.array([[0, 1], [0, 5]])
+    >>> np.sum(a)
+    array(6.)
+    >>> np.sum(a, axis=0)
+    array([0., 6.])
+    >>> np.sum(a, axis=1)
+    array([1., 5.])
+
+    With output ndarray:
+
+    >>> a = np.array([[0, 1], [0, 5]])
+    >>> b = np.ones((2,), dtype=np.float32)
+    >>> np.sum(a, axis = 0, out=b)
+    array([0., 6.])
+    >>> b
+    array([0., 6.])
+
+    If the accumulator is too small, overflow occurs:
+
+    >>> np.ones(128, dtype=np.int8).sum(dtype=np.int8)
+    array(-128, dtype=int8)
+    """
+    pass
+
+
+def _np_copy(a, out=None):
+    """
+    copy(a, out=None)
+
+    Return an array copy of the given object.
+
+    Parameters
+    ----------
+    a : ndarray
+        Input data.
+    out : ndarray or None, optional
+        Alternative output array in which to place the result. It must have
+        the same shape and dtype as the expected output.
+
+    Returns
+    -------
+    arr : ndarray
+        Array interpretation of `a`.
+
+    Notes
+    -------
+    This function differs from the original `numpy.copy
+    <https://docs.scipy.org/doc/numpy/reference/generated/numpy.copy.html>`_ in
+    the following aspects:
+
+    - Input type does not support Python native iterables(list, tuple, ...).
+    - ``out`` param: cannot perform auto broadcasting. ``out`` ndarray's shape must be the same as the expected output.
+    - ``out`` param: cannot perform auto type cast. ``out`` ndarray's dtype must be the same as the expected output.
+    - Does not support "order" parameter.
+
+    Examples
+    --------
+    Create an array x, with a reference y and a copy z:
+
+    >>> x = np.array([1, 2, 3])
+    >>> y = x
+    >>> z = np.copy(x)
+
+    Note that, when ``x`` is modified, ``y`` is also modified, but not ``z``:
+
+    >>> x[0] = 10
+    >>> x[0] == y[0]
+    array([1.])
+    >>> x[0] == z[0]
+    array([0.])
+    """
+    pass
+
+
+def _np_reshape(a, newshape, order='C', out=None):
+    """
+    reshape(a, newshape, order='C')
+
+    Gives a new shape to an array without changing its data.
+    This function always returns a copy of the input array if
+    ``out`` is not provided.
+
+    Parameters
+    ----------
+    a : ndarray
+        Array to be reshaped.
+    newshape : int or tuple of ints
+        The new shape should be compatible with the original shape. If
+        an integer, then the result will be a 1-D array of that length.
+        One shape dimension can be -1. In this case, the value is
+        inferred from the length of the array and remaining dimensions.
+    order : {'C'}, optional
+        Read the elements of `a` using this index order, and place the
+        elements into the reshaped array using this index order.  'C'
+        means to read / write the elements using C-like index order,
+        with the last axis index changing fastest, back to the first
+        axis index changing slowest. Other order types such as 'F'/'A'
+        may be added in the future.
+
+    Returns
+    -------
+    reshaped_array : ndarray
+        It will be always a copy of the original array. This behavior is different
+        from the official NumPy ``reshape`` operator where views of the original array may be
+        generated.
+
+    See Also
+    --------
+    ndarray.reshape : Equivalent method.
+    """
+    pass
diff --git a/python/mxnet/gluon/loss.py b/python/mxnet/gluon/loss.py
index 4cdb361eb146..45c3dee08139 100644
--- a/python/mxnet/gluon/loss.py
+++ b/python/mxnet/gluon/loss.py
@@ -189,9 +189,15 @@ def __init__(self, weight=None, batch_axis=0, **kwargs):
 
     def hybrid_forward(self, F, pred, label, sample_weight=None):
         label = _reshape_like(F, label, pred)
-        loss = F.abs(label - pred)
+        loss = F.np.abs(label - pred) if is_np_array() else F.abs(label - pred)
         loss = _apply_weighting(F, loss, self._weight, sample_weight)
-        return F.mean(loss, axis=self._batch_axis, exclude=True)
+        if is_np_array():
+            if F is ndarray:
+                return F.np.mean(loss, axis=tuple(range(1, loss.ndim)))
+            else:
+                return F.npx.batch_flatten(loss).mean(axis=1)
+        else:
+            return F.mean(loss, axis=self._batch_axis, exclude=True)
 
 
 class SigmoidBinaryCrossEntropyLoss(Loss):
diff --git a/python/mxnet/ndarray/numpy/linalg.py b/python/mxnet/ndarray/numpy/linalg.py
index 0222bb45d148..36f3f21a7588 100644
--- a/python/mxnet/ndarray/numpy/linalg.py
+++ b/python/mxnet/ndarray/numpy/linalg.py
@@ -18,5 +18,51 @@
 """Namespace for operators used in Gluon dispatched by F=ndarray."""
 
 from __future__ import absolute_import
+from . import _op as _mx_nd_np
 
-__all__ = []
+__all__ = ['norm']
+
+
+def norm(x, ord=None, axis=None, keepdims=False):
+    r"""Matrix or vector norm.
+
+    This function can only support Frobenius norm for now.
+    The Frobenius norm is given by [1]_:
+
+        :math:`||A||_F = [\sum_{i,j} abs(a_{i,j})^2]^{1/2}`
+
+    Parameters
+    ----------
+    x : ndarray
+        Input array.
+    ord : {'fro'}, optional
+        Order of the norm.
+    axis : {int, 2-tuple of ints, None}, optional
+        If `axis` is an integer, it specifies the axis of `x` along which to
+        compute the vector norms.  If `axis` is a 2-tuple, it specifies the
+        axes that hold 2-D matrices, and the matrix norms of these matrices
+        are computed.  If `axis` is None, the norm of the whole ndarray is
+        returned.
+
+    keepdims : bool, optional
+        If this is set to True, the axes which are normed over are left in the
+        result as dimensions with size one.  With this option the result will
+        broadcast correctly against the original `x`.
+
+    Returns
+    -------
+    n : float or ndarray
+        Norm of the matrix or vector(s).
+
+    References
+    ----------
+    .. [1] G. H. Golub and C. F. Van Loan, *Matrix Computations*,
+           Baltimore, MD, Johns Hopkins University Press, 1985, pg. 15
+    """
+    if ord is not None and ord != 'fro':
+        raise ValueError('only support Frobenius norm for now, received ord={}'.format(str(ord)))
+    if isinstance(axis, tuple) and len(axis) > 2:
+        raise ValueError('Improper number of dimensions to norm')
+    if ord == 'fro' and x.ndim > 2 and axis is None:
+        raise ValueError('Improper number of dimensions to norm')
+    return _mx_nd_np.sqrt(_mx_nd_np.sum(x * x, axis=axis, keepdims=keepdims))
diff --git a/python/mxnet/numpy/linalg.py b/python/mxnet/numpy/linalg.py
index c4109378e146..9758af47233d 100644
--- a/python/mxnet/numpy/linalg.py
+++ b/python/mxnet/numpy/linalg.py
@@ -18,5 +18,45 @@
 """Namespace for ops used in imperative programming."""
 
 from __future__ import absolute_import
+from ..ndarray import numpy as _mx_nd_np
 
-__all__ = []
+__all__ = ['norm']
+
+
+def norm(x, ord=None, axis=None, keepdims=False):
+    r"""Matrix or vector norm.
+
+    This function can only support Frobenius norm for now.
+    The Frobenius norm is given by [1]_:
+
+        :math:`||A||_F = [\sum_{i,j} abs(a_{i,j})^2]^{1/2}`
+
+    Parameters
+    ----------
+    x : ndarray
+        Input array.
+    ord : {'fro'}, optional
+        Order of the norm.
+    axis : {int, 2-tuple of ints, None}, optional
+        If `axis` is an integer, it specifies the axis of `x` along which to
+        compute the vector norms.  If `axis` is a 2-tuple, it specifies the
+        axes that hold 2-D matrices, and the matrix norms of these matrices
+        are computed.  If `axis` is None, the norm of the whole ndarray is
+        returned.
+
+    keepdims : bool, optional
+        If this is set to True, the axes which are normed over are left in the
+        result as dimensions with size one.  With this option the result will
+        broadcast correctly against the original `x`.
+
+    Returns
+    -------
+    n : float or ndarray
+        Norm of the matrix or vector(s).
+
+    References
+    ----------
+    .. [1] G. H. Golub and C. F. Van Loan, *Matrix Computations*,
+           Baltimore, MD, Johns Hopkins University Press, 1985, pg. 15
+    """
+    return _mx_nd_np.linalg.norm(x, ord, axis, keepdims)
diff --git a/python/mxnet/numpy/multiarray.py b/python/mxnet/numpy/multiarray.py
index 4eddb0380c09..1f8aa92f9851 100644
--- a/python/mxnet/numpy/multiarray.py
+++ b/python/mxnet/numpy/multiarray.py
@@ -59,6 +59,7 @@
 _NDARRAY_BASIC_INDEXING = 0
 _NDARRAY_ADVANCED_INDEXING = 1
 
+
 # This function is copied from ndarray.py since pylint
 # keeps giving false alarm error of undefined-all-variable
 def _new_alloc_handle(shape, ctx, delay_alloc, dtype=mx_real_t):
@@ -311,14 +312,14 @@ def _prepare_value_nd(self, value, bcast_shape, squeeze_axes=None):
         Note: mxnet.numpy.ndarray not support NDArray as assigned value.
         """
         if isinstance(value, numeric_types):
-            value_nd = full(bcast_shape, value, ctx=self.context, dtype=self.dtype)
+            value_nd = full(bcast_shape, value, ctx=self.ctx, dtype=self.dtype)
         elif isinstance(value, self.__class__):
-            value_nd = value.as_in_context(self.context)
+            value_nd = value.as_in_ctx(self.ctx)
             if value_nd.dtype != self.dtype:
                 value_nd = value_nd.astype(self.dtype)
         else:
             try:
-                value_nd = array(value, ctx=self.context, dtype=self.dtype)
+                value_nd = array(value, ctx=self.ctx, dtype=self.dtype)
             except:
                 raise TypeError('mxnet.np.ndarray does not support assignment with non-array-like '
                                 'object {} of type {}'.format(value, type(value)))
@@ -329,6 +330,19 @@ def _prepare_value_nd(self, value, bcast_shape, squeeze_axes=None):
             squeeze_axes = tuple([ax for ax in squeeze_axes if ax < len(value_nd.shape)])
             value_nd = value_nd.squeeze(axis=tuple(squeeze_axes))
 
+        # handle the cases like the following
+        # a = np.zeros((3, 3)), b = np.ones((1, 1, 1, 1, 3)), a[0] = b
+        # b cannot broadcast directly to a[0].shape unless its leading 1-size axes are trimmed
+        if value_nd.ndim > len(bcast_shape):
+            squeeze_axes = []
+            for i in range(value_nd.ndim - len(bcast_shape)):
+                if value_nd.shape[i] == 1:
+                    squeeze_axes.append(i)
+                else:
+                    break
+            if squeeze_axes:
+                value_nd = value_nd.squeeze(squeeze_axes)
+
         if value_nd.shape != bcast_shape:
             if value_nd.size == 0:
                 value_nd = value_nd.reshape(bcast_shape)
@@ -336,7 +350,6 @@ def _prepare_value_nd(self, value, bcast_shape, squeeze_axes=None):
                 value_nd = value_nd.broadcast_to(bcast_shape)
         return value_nd
 
-
     def __add__(self, other):
         """x.__add__(y) <=> x + y"""
         return add(self, other)
@@ -727,14 +740,14 @@ def copyto(self, other):
 
         Examples
         --------
-        >>> x = np.ones((2,3))
-        >>> y = np.zeros((2,3), ctx=mx.gpu(0))
+        >>> x = np.ones((2, 3))
+        >>> y = np.zeros((2, 3), ctx=npx.gpu(0))
         >>> z = x.copyto(y)
         >>> z is y
         True
-        >>> y.asnumpy()
+        >>> y
         array([[ 1.,  1.,  1.],
-               [ 1.,  1.,  1.]], dtype=float32)
+               [ 1.,  1.,  1.]])
         """
         if isinstance(other, ndarray):
             if other.handle is self.handle:
@@ -756,6 +769,11 @@ def argmax(self, axis=None, out=None):  # pylint: disable=arguments-differ
         return argmax(self, axis, out)
 
     def as_in_context(self, context):
+        """This function has been deprecated. Please refer to ``ndarray.as_in_ctx``."""
+        warnings.warn('ndarray.context has been renamed to ndarray.ctx', DeprecationWarning)
+        return self.as_nd_ndarray().as_in_context(context).as_np_ndarray()
+
+    def as_in_ctx(self, ctx):
         """Returns an array on the target device with the same value as this array.
 
         If the target context is the same as ``self.context``, then ``self`` is
@@ -771,15 +789,58 @@ def as_in_context(self, context):
         ndarray
             The target array.
         """
-        if self.context == context:
+        if self.ctx == ctx:
             return self
-        return self.copyto(context)
+        return self.copyto(ctx)
+
+    @property
+    def ctx(self):
+        """Device context of the array.
+
+        Examples
+        --------
+        >>> x = np.array([1, 2, 3, 4])
+        >>> x.ctx
+        cpu(0)
+        >>> type(x.ctx)
+        <class 'mxnet.context.Context'>
+        >>> y = np.zeros((2, 3), npx.gpu(0))
+        >>> y.ctx
+        gpu(0)
+        """
+        dev_typeid = ctypes.c_int()
+        dev_id = ctypes.c_int()
+        check_call(_LIB.MXNDArrayGetContext(
+            self.handle, ctypes.byref(dev_typeid), ctypes.byref(dev_id)))
+        return Context(Context.devtype2str[dev_typeid.value], dev_id.value)
+
+    @property
+    def context(self):
+        """This function has been deprecated. Please refer to ``ndarray.ctx``."""
+        warnings.warn('ndarray.context has been renamed to ndarray.ctx', DeprecationWarning)
+        return self.as_nd_ndarray().context
 
     def copy(self, order='C'):  # pylint: disable=arguments-differ
+        """Return a coyp of the array, keeping the same context.
+
+        Parameters
+        ----------
+        order : str
+            The memory layout of the copy. Currently, only c-contiguous memory
+            layout is supported.
+
+        Examples
+        --------
+        >>> x = np.ones((2, 3))
+        >>> y = x.copy()
+        >>> y
+        array([[ 1.,  1.,  1.],
+               [ 1.,  1.,  1.]])
+        """
         if order != 'C':
             raise NotImplementedError('ndarray.copy only supports order=\'C\', while '
                                       'received {}'.format(str(order)))
-        return super(ndarray, self).copy().as_np_ndarray()
+        return self.copyto(self.ctx)
 
     def dot(self, b, out=None):
         """Dot product of two arrays.
@@ -787,7 +848,7 @@ def dot(self, b, out=None):
         return _mx_np_op.dot(self, b, out=out)
 
     def reshape(self, *args, **kwargs):  # pylint: disable=arguments-differ
-        """Returns an array containing the same data with a new shape.
+        """Returns a copy of the array with a new shape.
 
         Notes
         -----
@@ -854,7 +915,7 @@ def broadcast_axes(self, *args, **kwargs):
 
     def repeat(self, repeats, axis=None):  # pylint: disable=arguments-differ
         """Repeat elements of an array."""
-        raise NotImplementedError
+        return _mx_np_op.repeat(self, repeats=repeats, axis=axis)
 
     def pad(self, *args, **kwargs):
         """Convenience fluent method for :py:func:`pad`.
@@ -1182,22 +1243,22 @@ def var(self, axis=None, dtype=None, out=None, ddof=0, keepdims=None):  # pylint
 
     def cumsum(self, axis=None, dtype=None, out=None):
         """Return the cumulative sum of the elements along the given axis."""
-        raise NotImplementedError
+        return _mx_np_op.cumsum(self, axis=axis, dtype=dtype, out=out)
 
     def tolist(self):
         return self.asnumpy().tolist()
 
     def max(self, axis=None, out=None, keepdims=False):  # pylint: disable=arguments-differ
         """Return the maximum along a given axis."""
-        raise NotImplementedError
+        return _mx_np_op.max(self, axis=axis, keepdims=keepdims, out=out)
 
-    def min(self, *args, **kwargs):
+    def min(self, axis=None, out=None, keepdims=False):  # pylint: disable=arguments-differ
         """Convenience fluent method for :py:func:`min`.
 
         The arguments are the same as for :py:func:`min`, with
         this array as data.
         """
-        raise NotImplementedError
+        return _mx_np_op.min(self, axis=axis, keepdims=keepdims, out=out)
 
     def norm(self, *args, **kwargs):
         """Convenience fluent method for :py:func:`norm`.
@@ -1549,7 +1610,7 @@ def tostype(self, stype):
 
 
 @set_module('mxnet.numpy')
-def empty(shape, dtype=float, order='C', ctx=None):
+def empty(shape, dtype=_np.float32, order='C', ctx=None):
     """Return a new array of given shape and type, without initializing entries.
 
     Parameters
@@ -1573,7 +1634,8 @@ def empty(shape, dtype=float, order='C', ctx=None):
         Array of uninitialized (arbitrary) data of the given shape, dtype, and order.
     """
     if order != 'C':
-        raise NotImplementedError
+        raise NotImplementedError('`empty` only supports order equal to `C`, while received {}'
+                                  .format(str(order)))
     if ctx is None:
         ctx = current_context()
     if dtype is None:
@@ -1609,7 +1671,7 @@ def array(object, dtype=None, ctx=None):
     if isinstance(object, ndarray):
         dtype = object.dtype if dtype is None else dtype
     else:
-        dtype = mx_real_t if dtype is None else dtype
+        dtype = _np.float32 if dtype is None else dtype
         if not isinstance(object, (ndarray, _np.ndarray)):
             try:
                 object = _np.array(object, dtype=dtype)
diff --git a/python/mxnet/symbol/numpy/_symbol.py b/python/mxnet/symbol/numpy/_symbol.py
index 0841c0e4d2cc..077008aba119 100644
--- a/python/mxnet/symbol/numpy/_symbol.py
+++ b/python/mxnet/symbol/numpy/_symbol.py
@@ -223,11 +223,11 @@ def dot(self, b, out=None):
         return _mx_np_op.dot(self, b, out=out)
 
     def reshape(self, *args, **kwargs):  # pylint: disable=arguments-differ
-        """Returns an array containing the same data with a new shape.
+        """Returns a copy of the array with a new shape.
 
         Notes
         -----
-        Unlike the free function `numpy.reshape`, this method on `ndarray` allows
+        Unlike the free function `mxnet.numpy.reshape`, this method on `ndarray` allows
         the elements of the shape parameter to be passed in as separate arguments.
         For example, ``a.reshape(10, 11)`` is equivalent to
         ``a.reshape((10, 11))``.
@@ -289,7 +289,7 @@ def broadcast_axes(self, *args, **kwargs):
 
     def repeat(self, repeats, axis=None):  # pylint: disable=arguments-differ
         """Repeat elements of an array."""
-        raise NotImplementedError
+        return _mx_np_op.repeat(self, repeats=repeats, axis=axis)
 
     def pad(self, *args, **kwargs):
         """Convenience fluent method for :py:func:`pad`.
@@ -543,19 +543,15 @@ def var(self, axis=None, dtype=None, out=None, ddof=0, keepdims=None):  # pylint
 
     def cumsum(self, axis=None, dtype=None, out=None):
         """Return the cumulative sum of the elements along the given axis."""
-        raise NotImplementedError
+        return _mx_np_op.cumsum(self, axis=axis, dtype=dtype, out=out)
 
     def max(self, axis=None, out=None, keepdims=False):  # pylint: disable=arguments-differ
         """Return the maximum along a given axis."""
-        raise NotImplementedError
-
-    def min(self, *args, **kwargs):
-        """Convenience fluent method for :py:func:`min`.
+        return _mx_np_op.max(self, axis=axis, keepdims=keepdims, out=out)
 
-        The arguments are the same as for :py:func:`min`, with
-        this array as data.
-        """
-        raise NotImplementedError
+    def min(self, axis=None, out=None, keepdims=False):  # pylint: disable=arguments-differ
+        """Return the minimum along a given axis."""
+        return _mx_np_op.min(self, axis=axis, keepdims=keepdims, out=out)
 
     def norm(self, *args, **kwargs):
         """Convenience fluent method for :py:func:`norm`.
diff --git a/python/mxnet/symbol/numpy/linalg.py b/python/mxnet/symbol/numpy/linalg.py
index 28cfd0f3806a..d1918ef8b903 100644
--- a/python/mxnet/symbol/numpy/linalg.py
+++ b/python/mxnet/symbol/numpy/linalg.py
@@ -18,5 +18,51 @@
 """Namespace for operators used in Gluon dispatched by F=symbol."""
 
 from __future__ import absolute_import
+from . import _symbol
+from . import _op as _mx_sym_np
 
-__all__ = []
+__all__ = ['norm']
+
+
+def norm(x, ord=None, axis=None, keepdims=False):
+    r"""Matrix or vector norm.
+
+    This function can only support Frobenius norm for now.
+    The Frobenius norm is given by [1]_:
+
+        :math:`||A||_F = [\sum_{i,j} abs(a_{i,j})^2]^{1/2}`
+
+    Parameters
+    ----------
+    x : ndarray
+        Input array.
+    ord : {'fro'}, optional
+        Order of the norm.
+    axis : {int, 2-tuple of ints, None}, optional
+        If `axis` is an integer, it specifies the axis of `x` along which to
+        compute the vector norms.  If `axis` is a 2-tuple, it specifies the
+        axes that hold 2-D matrices, and the matrix norms of these matrices
+        are computed.  If `axis` is None, the norm of the whole ndarray is
+        returned.
+
+    keepdims : bool, optional
+        If this is set to True, the axes which are normed over are left in the
+        result as dimensions with size one.  With this option the result will
+        broadcast correctly against the original `x`.
+
+    Returns
+    -------
+    n : float or ndarray
+        Norm of the matrix or vector(s).
+
+    References
+    ----------
+    .. [1] G. H. Golub and C. F. Van Loan, *Matrix Computations*,
+           Baltimore, MD, Johns Hopkins University Press, 1985, pg. 15
+    """
+    if ord is not None and ord != 'fro':
+        raise ValueError('only support Frobenius norm for now, received ord={}'.format(str(ord)))
+    if isinstance(axis, tuple) and len(axis) > 2:
+        raise ValueError('Improper number of dimensions to norm')
+    # TODO(junwu): When ord = 'fro', axis = None, and x.ndim > 2, raise exception
+    return _symbol.sqrt(_mx_sym_np.sum(x * x, axis=axis, keepdims=keepdims))
diff --git a/tests/python/unittest/test_numpy_gluon.py b/tests/python/unittest/test_numpy_gluon.py
index e96f829a8580..62ea38fc0c13 100644
--- a/tests/python/unittest/test_numpy_gluon.py
+++ b/tests/python/unittest/test_numpy_gluon.py
@@ -19,9 +19,11 @@
 from __future__ import absolute_import
 from __future__ import division
 
+import numpy as _np
 import mxnet as mx
 from mxnet import gluon, autograd, np
-from mxnet.test_utils import use_np
+from mxnet.test_utils import use_np, assert_almost_equal
+from common import with_seed
 
 
 def test_create_np_param():
@@ -108,6 +110,40 @@ def hybrid_forward(self, F, pred, label):
         trainer.step(1)
 
 
+@with_seed()
+@use_np
+def test_np_loss_ndarray():
+    # Ported from test_loss.test_loss_ndarray
+    output = np.array([1, 2, 3, 4])
+    label = np.array([1, 3, 5, 7])
+    weighting = np.array([0.5, 1, 0.5, 1])
+
+    loss = gluon.loss.L1Loss()
+    assert np.sum(loss(output, label)) == 6.
+    loss = gluon.loss.L1Loss(weight=0.5)
+    assert np.sum(loss(output, label)) == 3.
+    loss = gluon.loss.L1Loss()
+    assert np.sum(loss(output, label, weighting)) == 5.
+
+    loss = gluon.loss.L2Loss()
+    assert np.sum(loss(output, label)) == 7.
+    loss = gluon.loss.L2Loss(weight=0.25)
+    assert np.sum(loss(output, label)) == 1.75
+    loss = gluon.loss.L2Loss()
+    assert np.sum(loss(output, label, weighting)) == 6
+
+    output = np.array([[0, 2], [1, 4]])
+    label = np.array([0, 1])
+    weighting = np.array([[0.5], [1.0]])
+
+    loss = gluon.loss.SoftmaxCrossEntropyLoss()
+    L = loss(output, label).asnumpy()
+    assert_almost_equal(L, _np.array([2.12692809,  0.04858733]), use_broadcast=False)
+
+    L = loss(output, label, weighting).asnumpy()
+    assert_almost_equal(L, _np.array([1.06346405,  0.04858733]), use_broadcast=False)
+
+
 if __name__ == '__main__':
     import nose
     nose.runmodule()
diff --git a/tests/python/unittest/test_numpy_ndarray.py b/tests/python/unittest/test_numpy_ndarray.py
index 883060466836..bffa7a00dccb 100644
--- a/tests/python/unittest/test_numpy_ndarray.py
+++ b/tests/python/unittest/test_numpy_ndarray.py
@@ -26,12 +26,45 @@
 from mxnet.test_utils import same, assert_almost_equal, rand_shape_nd, rand_ndarray, retry, assert_exception, use_np
 from common import with_seed, TemporaryDirectory
 from mxnet.test_utils import verify_generator, gen_buckets_probs_with_ppf
+from mxnet.ndarray.ndarray import py_slice
+from mxnet.base import integer_types
 import scipy.stats as ss
 
 
 @with_seed()
 @use_np
-def test_array_creation():
+def test_np_empty():
+    dtypes = [np.int8, np.int32, np.float16, np.float32, np.float64, None]
+    expected_dtypes = [np.int8, np.int32, np.float16, np.float32, np.float64, np.float32]
+    orders = ['C', 'F', 'A']
+    shapes = [
+        (),
+        0,
+        (0,),
+        (0, 0),
+        2,
+        (2,),
+        (3, 0),
+        (4, 5),
+        (1, 1, 1, 1),
+    ]
+    ctxes = [npx.current_context(), None]
+    for dtype, expected_dtype in zip(dtypes, expected_dtypes):
+        for shape in shapes:
+            for order in orders:
+                for ctx in ctxes:
+                    if order == 'C':
+                        ret = np.empty(shape, dtype, order, ctx)
+                        assert ret.dtype == expected_dtype
+                        assert ret.shape == shape if isinstance(shape, tuple) else (shape,)
+                        assert ret.ctx == npx.current_context()
+                    else:
+                        assert_exception(np.empty, NotImplementedError, shape, dtype, order, ctx)
+
+
+@with_seed()
+@use_np
+def test_np_array_creation():
     dtypes = [_np.int8, _np.int32, _np.float16, _np.float32, _np.float64, None]
     objects = [
         [],
@@ -54,7 +87,7 @@ def test_array_creation():
 
 @with_seed()
 @use_np
-def test_zeros():
+def test_np_zeros():
     # test np.zeros in Gluon
     class TestZeros(HybridBlock):
         def __init__(self, shape, dtype=None):
@@ -102,7 +135,7 @@ def check_zero_array_creation(shape, dtype):
 
 @with_seed()
 @use_np
-def test_ones():
+def test_np_ones():
     # test np.ones in Gluon
     class TestOnes(HybridBlock):
         def __init__(self, shape, dtype=None):
@@ -149,7 +182,7 @@ def check_ones_array_creation(shape, dtype):
 
 
 @with_seed()
-def test_ndarray_binary_element_wise_ops():
+def test_np_ndarray_binary_element_wise_ops():
     np_op_map = {
         '+': _np.add,
         '*': _np.multiply,
@@ -304,7 +337,7 @@ def check_binary_op_result(shape1, shape2, op, dtype=None):
 
 
 @with_seed()
-def test_hybrid_block_multiple_outputs():
+def test_np_hybrid_block_multiple_outputs():
     @use_np
     class TestAllNumpyOutputs(HybridBlock):
         def hybrid_forward(self, F, x, *args, **kwargs):
@@ -338,7 +371,7 @@ def hybrid_forward(self, F, x, *args, **kwargs):
 
 @with_seed()
 @use_np
-def test_grad_ndarray_type():
+def test_np_grad_ndarray_type():
     data = np.array(2, dtype=_np.float32)
     data.attach_grad()
     assert type(data.grad) == np.ndarray
@@ -379,7 +412,7 @@ def test_np_ndarray_copy():
 def test_np_ndarray_indexing():
     def np_int(index, int_type=np.int32):
         """
-        Helper function for testing indexing that converts slices to slices of ints or None, and tuples to 
+        Helper function for testing indexing that converts slices to slices of ints or None, and tuples to
         tuples of ints or None.
         """
         def convert(num):
@@ -401,7 +434,7 @@ def convert(num):
         else:
             assert False
 
-    # Copied from test_ndarray.py. Under construction. 
+    # Copied from test_ndarray.py. Under construction.
     def test_getitem(np_array, index):
         np_index = index
         if type(index) == mx.nd.NDArray:  # use of NDArray is prohibited
@@ -439,6 +472,13 @@ def assert_same(np_array, np_index, mx_array, mx_index, mx_value, np_value=None)
 
             assert same(np_array, mx_array.asnumpy())
 
+        def _is_basic_index(index):
+            if isinstance(index, (integer_types, py_slice)):
+                return True
+            if isinstance(index, tuple) and all(isinstance(i, (integer_types, py_slice)) for i in index):
+                return True
+            return False
+
         np_index = index  # keep this native numpy type
         if isinstance(index, np.ndarray):
             np_index = index.asnumpy()
@@ -467,6 +507,13 @@ def assert_same(np_array, np_index, mx_array, mx_index, mx_value, np_value=None)
             assert_same(np_array, np_index, mx_array, index, np.array(np_value))
             # test native numpy array with broadcast
             assert_same(np_array, np_index, mx_array, index, np_value)
+
+            # test value shape are expanded to be longer than index array's shape
+            # this is currently only supported in basic indexing
+            if _is_basic_index(index):
+                expanded_value_shape = (1, 1, 1) + np_value.shape
+                assert_same(np_array, np_index, mx_array, index, np.array(np_value.reshape(expanded_value_shape)))
+                assert_same(np_array, np_index, mx_array, index, np_value.reshape(expanded_value_shape))
             # test list with broadcast
             assert_same(np_array, np_index, mx_array, index,
                         [_np.random.randint(low=-10000, high=0)] * indexed_array_shape[-1])
@@ -664,18 +711,18 @@ def test_setitem_autograd(np_array, index):
         test_setitem(np_array, index)
         test_getitem_autograd(np_array, index)
         test_setitem_autograd(np_array, index)
-    
+
     # Test indexing to zero-size tensors
     index_list = [
-        (slice(0, 0), slice(0, 0), 1, 2),  
-        (slice(0, 0), slice(0, 0), slice(0, 0), slice(0, 0)),  
+        (slice(0, 0), slice(0, 0), 1, 2),
+        (slice(0, 0), slice(0, 0), slice(0, 0), slice(0, 0)),
     ]
     for index in index_list:
         test_getitem(np_array, index)
         test_setitem(np_array, index)
         test_getitem_autograd(np_array, index)
         test_setitem_autograd(np_array, index)
-    
+
     # test zero-size tensors get and setitem
     shapes_indices = [
                         ((0), [slice(None, None, None)]),
diff --git a/tests/python/unittest/test_numpy_op.py b/tests/python/unittest/test_numpy_op.py
index 0f7355b7ef13..c5b0907fb7a8 100644
--- a/tests/python/unittest/test_numpy_op.py
+++ b/tests/python/unittest/test_numpy_op.py
@@ -288,7 +288,7 @@ def __init__(self, axis=None, keepdims=False):
             self._keepdims = keepdims
 
         def hybrid_forward(self, F, a, *args, **kwargs):
-            return F.np.max(a, axis=self._axis, keepdims=self._keepdims)
+            return a.max(axis=self._axis, keepdims=self._keepdims)
 
     class TestMin(HybridBlock):
         def __init__(self, axis=None, keepdims=False):
@@ -297,7 +297,7 @@ def __init__(self, axis=None, keepdims=False):
             self._keepdims = keepdims
 
         def hybrid_forward(self, F, a, *args, **kwargs):
-            return F.np.min(a, axis=self._axis, keepdims=self._keepdims)
+            return a.min(axis=self._axis, keepdims=self._keepdims)
 
     def is_int(dtype):
         return 'int' == dtype
@@ -326,12 +326,8 @@ def get_grad(axis, func_name):
             raise ValueError('axis should be int or None or ()')
 
     def _test_np_exception(func, shape, dim):
-        x = _np.random.uniform(-1.0, 1.0, shape)
-        x = mx.nd.array(x).as_np_ndarray()
-        if func == 'max':
-            out = mx.np.max(x)
-        else:
-            out = mx.np.min(x)
+        x = np.random.uniform(-1.0, 1.0, shape)
+        out = getattr(x, func)()
         assert out.ndim == dim, 'dimension mismatch, output.ndim={}, dim={}'.format(output.ndim, dim)
 
     in_data_dim = random.choice([2, 3, 4])
@@ -1620,7 +1616,7 @@ def __init__(self, axis=None, dtype=None):
             self._dtype = dtype
 
         def hybrid_forward(self, F, a):
-            return F.np.cumsum(a, axis=self._axis, dtype=self._dtype)
+            return a.cumsum(axis=self._axis, dtype=self._dtype)
 
     shapes = [(2, 3, 4), (2, 0, 3), ()]
     for hybridize in [True, False]:
@@ -1790,6 +1786,73 @@ def hybrid_forward(self, F, x):
                 assert mx_out.shape == np_out.shape
 
 
+@with_seed()
+@use_np
+def test_np_repeat():
+    config = [
+        ((), 2, None),
+        ((), 0, None),
+        ((4, 2), 2, None),
+        ((4, 2), 2, 0),
+        ((4, 2), 2, 1),
+        ((4, 2), 2, -1),
+    ]
+
+    class TestRepeat(HybridBlock):
+        def __init__(self, repeats, axis=None):
+            super(TestRepeat, self).__init__()
+            self._repeats = repeats
+            self._axis = axis
+
+        def hybrid_forward(self, F, x):
+            return x.repeat(self._repeats, self._axis)
+
+    for shape, repeats, axis in config:
+        data_np = _np.random.randint(low=0, high=1000, size=shape)
+        data_mx = np.array(data_np, dtype=data_np.dtype)
+        ret_np = data_np.repeat(repeats, axis)
+        ret_mx = data_mx.repeat(repeats, axis)
+        assert same(ret_mx.asnumpy(), ret_np)
+
+        net = TestRepeat(repeats, axis)
+        for hybrid in [False, True]:
+            if hybrid:
+                net.hybridize()
+            ret_mx = net(data_mx)
+            assert same(ret_mx.asnumpy(), ret_np)
+
+
+@with_seed()
+@use_np
+def test_np_linalg_norm():
+    @use_np
+    class TestLinalgNorm(HybridBlock):
+        def __init__(self, ord=None, axis=None, keepdims=False):
+            super(TestLinalgNorm, self).__init__()
+            self._ord = ord
+            self._axis = axis
+            self._keepdims = keepdims
+
+        def hybrid_forward(self, F, x):
+            return F.np.linalg.norm(x, ord=self._ord, axis=self._axis, keepdims=self._keepdims)
+
+    a = np.arange(5 * 6 * 7 * 8).reshape((5, 6, 7, 8))
+    ords = [None, 'fro']
+    axes = [None, (0, 2), (1, 0), (1, 2)]
+    for ord in ords:
+        for axis in axes:
+            if ord == 'fro' and axis is None and a.ndim > 2:
+                continue
+            for keepdims in [False, True]:
+                for hybridize in [False, True]:
+                    net = TestLinalgNorm(ord, axis, keepdims)
+                    if hybridize:
+                        net.hybridize()
+                    mx_ret = net(a)
+                    np_ret = _np.linalg.norm(a.asnumpy(), ord=ord, axis=axis, keepdims=keepdims)
+                    assert_almost_equal(mx_ret.asnumpy(), np_ret, atol=1e-5, rtol=1e-4)
+
+
 if __name__ == '__main__':
     import nose
     nose.runmodule()