From 00423dc55f22878f9359c346df6226bea4445186 Mon Sep 17 00:00:00 2001
From: Hameer Abbasi <hameerabbasi@yahoo.com>
Date: Fri, 19 Jan 2018 01:28:25 +0100
Subject: [PATCH 1/9] Add tests for scipy spmatrices from the left.

---
 requirements.txt         |   2 +-
 sparse/coo.py            | 115 ++++-----------------------------------
 sparse/tests/test_coo.py |  14 +++++
 3 files changed, 25 insertions(+), 106 deletions(-)

diff --git a/requirements.txt b/requirements.txt
index df1123ff..f1802810 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,3 +1,3 @@
-numpy
+numpy >= 1.13
 scipy >= 0.19
 six
diff --git a/sparse/coo.py b/sparse/coo.py
index f0b5f0b1..cb509ed7 100644
--- a/sparse/coo.py
+++ b/sparse/coo.py
@@ -7,6 +7,7 @@
 
 import numpy as np
 import scipy.sparse
+from numpy.lib.mixins import NDArrayOperatorsMixin
 
 from .slicing import normalize_index
 from .utils import _zero_of_dtype
@@ -20,7 +21,7 @@
     pass
 
 
-class COO(object):
+class COO(NDArrayOperatorsMixin):
     """
     A sparse multidimensional array.
 
@@ -1221,6 +1222,10 @@ def __rmatmul__(self, other):
             return NotImplemented
 
     def __array_ufunc__(self, ufunc, method, *inputs, **kwargs):
+        out = kwargs.pop('out', None)
+        if out is not None:
+            return NotImplemented
+
         if method == '__call__':
             return COO._elemwise(ufunc, *inputs, **kwargs)
         elif method == 'reduce':
@@ -1522,105 +1527,6 @@ def sum_duplicates(self):
         self.coords = coords
         self.has_duplicates = False
 
-    def __add__(self, other):
-        return self.elemwise(operator.add, other)
-
-    def __radd__(self, other):
-        return self.elemwise(_reverse_self_other(operator.add), other)
-
-    def __neg__(self):
-        return self.elemwise(operator.neg)
-
-    def __sub__(self, other):
-        return self.elemwise(operator.sub, other)
-
-    def __rsub__(self, other):
-        return self.elemwise(_reverse_self_other(operator.sub), other)
-
-    def __mul__(self, other):
-        return self.elemwise(operator.mul, other)
-
-    def __rmul__(self, other):
-        return self.elemwise(_reverse_self_other(operator.mul), other)
-
-    def __truediv__(self, other):
-        return self.elemwise(operator.truediv, other)
-
-    def __rtruediv__(self, other):
-        return self.elemwise(_reverse_self_other(operator.truediv), other)
-
-    def __floordiv__(self, other):
-        return self.elemwise(operator.floordiv, other)
-
-    def __rfloordiv__(self, other):
-        return self.elemwise(_reverse_self_other(operator.floordiv), other)
-
-    __div__ = __truediv__
-    __rdiv__ = __rtruediv__
-
-    def __pow__(self, other):
-        return self.elemwise(operator.pow, other)
-
-    def __rpow__(self, other):
-        return self.elemwise(_reverse_self_other(operator.pow), other)
-
-    def __mod__(self, other):
-        return self.elemwise(operator.mod, other)
-
-    def __rmod__(self, other):
-        return self.elemwise(_reverse_self_other(operator.mod), other)
-
-    def __and__(self, other):
-        return self.elemwise(operator.and_, other)
-
-    def __rand__(self, other):
-        return self.elemwise(_reverse_self_other(operator.and_), other)
-
-    def __xor__(self, other):
-        return self.elemwise(operator.xor, other)
-
-    def __rxor__(self, other):
-        return self.elemwise(_reverse_self_other(operator.xor), other)
-
-    def __or__(self, other):
-        return self.elemwise(operator.or_, other)
-
-    def __ror__(self, other):
-        return self.elemwise(_reverse_self_other(operator.or_), other)
-
-    def __invert__(self):
-        return self.elemwise(operator.invert)
-
-    def __gt__(self, other):
-        return self.elemwise(operator.gt, other)
-
-    def __ge__(self, other):
-        return self.elemwise(operator.ge, other)
-
-    def __lt__(self, other):
-        return self.elemwise(operator.lt, other)
-
-    def __le__(self, other):
-        return self.elemwise(operator.le, other)
-
-    def __eq__(self, other):
-        return self.elemwise(operator.eq, other)
-
-    def __ne__(self, other):
-        return self.elemwise(operator.ne, other)
-
-    def __lshift__(self, other):
-        return self.elemwise(operator.lshift, other)
-
-    def __rlshift__(self, other):
-        return self.elemwise(_reverse_self_other(operator.lshift), other)
-
-    def __rshift__(self, other):
-        return self.elemwise(operator.rshift, other)
-
-    def __rrshift__(self, other):
-        return self.elemwise(_reverse_self_other(operator.rshift), other)
-
     @staticmethod
     def _elemwise(func, *args, **kwargs):
         if len(args) == 0:
@@ -1628,7 +1534,7 @@ def _elemwise(func, *args, **kwargs):
 
         self = args[0]
         if isinstance(self, scipy.sparse.spmatrix):
-            self = COO.from_numpy(self)
+            self = COO.from_scipy_sparse(self)
         elif np.isscalar(self) or (isinstance(self, np.ndarray)
                                    and self.ndim == 0):
             func = partial(func, self)
@@ -1712,7 +1618,7 @@ def broadcast_to(self, shape):
         return COO(coords, data, shape=result_shape, has_duplicates=self.has_duplicates,
                    sorted=self.sorted)
 
-    def __abs__(self):
+    def abs(self):
         """
         Calculate the absolute value element-wise.
 
@@ -1722,8 +1628,6 @@ def __abs__(self):
         """
         return self.elemwise(abs)
 
-    abs = __abs__
-
     def exp(self, out=None):
         """
         Calculate the exponential of all elements in the array.
@@ -2464,7 +2368,8 @@ def _elemwise_binary(func, self, other, *args, **kwargs):
     self_zero = _zero_of_dtype(self.dtype)
     other_zero = _zero_of_dtype(other.dtype)
 
-    func_zero = _zero_of_dtype(func(self_zero, other_zero, *args, **kwargs).dtype)
+    func_value = func(self_zero, other_zero, *args, **kwargs)
+    func_zero = _zero_of_dtype(np.dtype(func_value))
     if check and func(self_zero, other_zero, *args, **kwargs) != func_zero:
         raise ValueError("Performing this operation would produce "
                          "a dense result: %s" % str(func))
diff --git a/sparse/tests/test_coo.py b/sparse/tests/test_coo.py
index f5883d70..28772976 100644
--- a/sparse/tests/test_coo.py
+++ b/sparse/tests/test_coo.py
@@ -256,6 +256,20 @@ def test_op_scipy_sparse(func):
     assert_eq(func(x, y), func(xs, ys))
 
 
+@pytest.mark.parametrize('func', [
+    operator.mul, operator.add, operator.sub, operator.gt,
+    operator.lt, operator.ne
+])
+def test_op_scipy_sparse_left(func):
+    ys = sparse.random((3, 4), density=0.5)
+    x = sparse.random((3, 4), density=0.5).todense()
+
+    xs = scipy.sparse.csr_matrix(x)
+    y = ys.todense()
+
+    assert_eq(func(x, y), func(xs, ys))
+
+
 @pytest.mark.parametrize('func, scalar', [
     (operator.mul, 5),
     (operator.add, 0),

From 08e559b251e5b78bb4a73bf7a7dc18e336479840 Mon Sep 17 00:00:00 2001
From: Hameer Abbasi <hameerabbasi@yahoo.com>
Date: Fri, 19 Jan 2018 01:37:18 +0100
Subject: [PATCH 2/9] Fix failing tests.

---
 sparse/tests/test_coo.py | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/sparse/tests/test_coo.py b/sparse/tests/test_coo.py
index 28772976..b6a2fa44 100644
--- a/sparse/tests/test_coo.py
+++ b/sparse/tests/test_coo.py
@@ -257,8 +257,12 @@ def test_op_scipy_sparse(func):
 
 
 @pytest.mark.parametrize('func', [
-    operator.mul, operator.add, operator.sub, operator.gt,
-    operator.lt, operator.ne
+    operator.mul,
+    operator.add,
+    operator.sub,
+    pytest.mark.xfail(operator.gt, reason='Scipy sparse doesn\'t support this yet.'),
+    pytest.mark.xfail(operator.lt, reason='Scipy sparse doesn\'t support this yet.'),
+    pytest.mark.xfail(operator.ne, reason='Scipy sparse doesn\'t support this yet.'),
 ])
 def test_op_scipy_sparse_left(func):
     ys = sparse.random((3, 4), density=0.5)

From e36bc8c0329a8b121bee6d3d295d901ac5c08fc6 Mon Sep 17 00:00:00 2001
From: Hameer Abbasi <hameerabbasi@yahoo.com>
Date: Fri, 19 Jan 2018 10:11:38 +0100
Subject: [PATCH 3/9] Update docs.

---
 docs/generated/sparse.COO.rst                 |  2 +-
 docs/user_manual/operations.rst               |  2 +-
 docs/user_manual/operations/elemwise.rst      |  7 ++--
 .../operations/{basic.rst => operators.rst}   | 28 +++++++++++++---
 sparse/coo.py                                 | 15 +++++----
 sparse/tests/test_coo.py                      | 32 -------------------
 6 files changed, 38 insertions(+), 48 deletions(-)
 rename docs/user_manual/operations/{basic.rst => operators.rst} (79%)

diff --git a/docs/generated/sparse.COO.rst b/docs/generated/sparse.COO.rst
index 86b12545..078b2846 100644
--- a/docs/generated/sparse.COO.rst
+++ b/docs/generated/sparse.COO.rst
@@ -6,7 +6,7 @@ COO
 .. autoclass:: COO
 
    .. note::
-      :obj:`COO` objects also support :doc:`operators <../user_manual/operations/basic>`
+      :obj:`COO` objects also support :doc:`operators <../user_manual/operations/operators>`
       and :doc:`indexing <../user_manual/operations/indexing>`
 
    .. rubric:: Attributes
diff --git a/docs/user_manual/operations.rst b/docs/user_manual/operations.rst
index 3794a698..82f98c08 100644
--- a/docs/user_manual/operations.rst
+++ b/docs/user_manual/operations.rst
@@ -8,7 +8,7 @@ common operations <operations/other>`_
 .. toctree::
    :maxdepth: 2
 
-   operations/basic
+   operations/operators
    operations/elemwise
    operations/reductions
    operations/indexing
diff --git a/docs/user_manual/operations/elemwise.rst b/docs/user_manual/operations/elemwise.rst
index b0c2a3f9..b54e26fa 100644
--- a/docs/user_manual/operations/elemwise.rst
+++ b/docs/user_manual/operations/elemwise.rst
@@ -26,14 +26,15 @@ However, the following are all unsupported and will raise a :obj:`ValueError`:
    np.log(x)
 
 Notice that you can apply any unary or binary :obj:`numpy.ufunc` to :obj:`COO`
-arrays, :obj:`scipy.sparse.spmatrix` objects and scalars and it will work so
-long as the result is not dense.
+arrays, and :obj:`numpy.ndarray` objects and scalars and it will work so
+long as the result is not dense. When applying to :obj:`numpy.ndarray` objects,
+we check that operating on the array with zero would always produce a zero.
 
 :obj:`COO.elemwise`
 -------------------
 This function allows you to apply any arbitrary unary or binary function where
 the first object is :obj:`COO`, and the second is a scalar, :obj:`COO`, or
-a :obj:`scipy.sparse.spmatrix`. For example, the following will add two
+a :obj:`numpy.ndarray`. For example, the following will add two
 :obj:`COO` objects:
 
 .. code-block:: python
diff --git a/docs/user_manual/operations/basic.rst b/docs/user_manual/operations/operators.rst
similarity index 79%
rename from docs/user_manual/operations/basic.rst
rename to docs/user_manual/operations/operators.rst
index c47913f3..47c4c635 100644
--- a/docs/user_manual/operations/basic.rst
+++ b/docs/user_manual/operations/operators.rst
@@ -1,9 +1,9 @@
 .. currentmodule:: sparse
 
-Basic Operations
-================
+Operators
+=========
 :obj:`COO` objects can have a number of operators applied to them. They support
-operations with scalars, :obj:`scipy.sparse.spmatrix` objects, and other
+operations with scalars, :obj:`numpy.ndarray` objects, and other
 :obj:`COO` objects. For example, to get the sum of two :obj:`COO` objects, you
 would do the following:
 
@@ -53,6 +53,26 @@ If densification is needed, it must be explicit. In other words, you must call
 :obj:`COO.todense` on the :obj:`COO` object. If both operands are :obj:`COO`,
 both must be densified.
 
+Operations with :obj:`numpy.ndarray`
+------------------------------------
+Certain operations with :obj:`numpy.ndarray` are also supported. For example,
+the following are all allowed if :code:`x` is a :obj:`numpy.ndarray` and
+:code:`(x == 0).all()` evaluates to :code:`True`:
+
+.. code-block:: python
+
+   x + y
+   x - y
+
+The following is true so long as there are no infinities or NaNs in :code:`x`:
+
+.. code-block:: python
+
+   x * y
+
+In general, if operating on the :code:`numpy.ndarray` with a zero would produce
+all-zeros then the operation is supported.
+
 Broadcasting
 ------------
 All binary operators support :obj:`broadcasting <numpy.doc.broadcasting>`.
@@ -67,7 +87,7 @@ will raise a :obj:`ValueError`.
 Full List of Operators
 ----------------------
 Here, :code:`x` and :code:`y` can be :obj:`COO` arrays,
-:obj:`scipy.sparse.spmatrix` objects or scalars, keeping in mind :ref:`auto
+:obj:`numpy.ndarray` objects or scalars, keeping in mind :ref:`auto
 densification rules <auto-densification>`. The following operators are supported:
 
 * Basic algebraic operations
diff --git a/sparse/coo.py b/sparse/coo.py
index cb509ed7..f1b3e3f6 100644
--- a/sparse/coo.py
+++ b/sparse/coo.py
@@ -1533,10 +1533,8 @@ def _elemwise(func, *args, **kwargs):
             return func()
 
         self = args[0]
-        if isinstance(self, scipy.sparse.spmatrix):
-            self = COO.from_scipy_sparse(self)
-        elif np.isscalar(self) or (isinstance(self, np.ndarray)
-                                   and self.ndim == 0):
+        if np.isscalar(self) or (isinstance(self, np.ndarray)
+                                 and self.ndim == 0):
             func = partial(func, self)
             other = args[1]
             if isinstance(other, scipy.sparse.spmatrix):
@@ -1547,8 +1545,6 @@ def _elemwise(func, *args, **kwargs):
             return _elemwise_unary(func, self, *args[1:], **kwargs)
         else:
             other = args[1]
-            if isinstance(other, scipy.sparse.spmatrix):
-                other = COO.from_scipy_sparse(other)
 
             if isinstance(other, COO) or isinstance(other, np.ndarray):
                 return _elemwise_binary(func, self, other, *args[2:], **kwargs)
@@ -1565,7 +1561,7 @@ def elemwise(self, func, *args, **kwargs):
             The function to apply to one or two arguments.
         args : tuple, optional
             The extra arguments to pass to the function. If :code:`args[0]` is a COO object,
-            a scipy.sparse.spmatrix or a scalar; the function will be treated as a binary
+            or a scalar; the function will be treated as a binary
             function. Otherwise, it will be treated as a unary function.
         kwargs : dict, optional
             The kwargs to pass to the function.
@@ -1584,6 +1580,11 @@ def elemwise(self, func, *args, **kwargs):
         --------
         :obj:`numpy.ufunc` : A similar Numpy construct. Note that any :code:`ufunc` can be used
             as the :code:`func` input to this function.
+
+        Notes
+        -----
+        In the future, this function may support functions of more than two arguments. Therefore,
+        it is best to pass in any additional arguments as keyword arguments.
         """
         return COO._elemwise(func, self, *args, **kwargs)
 
diff --git a/sparse/tests/test_coo.py b/sparse/tests/test_coo.py
index b6a2fa44..d270af42 100644
--- a/sparse/tests/test_coo.py
+++ b/sparse/tests/test_coo.py
@@ -242,38 +242,6 @@ def test_auto_densification_fails(func):
         func(xs, ys)
 
 
-@pytest.mark.parametrize('func', [
-    operator.mul, operator.add, operator.sub, operator.gt,
-    operator.lt, operator.ne
-])
-def test_op_scipy_sparse(func):
-    xs = sparse.random((3, 4), density=0.5)
-    y = sparse.random((3, 4), density=0.5).todense()
-
-    ys = scipy.sparse.csr_matrix(y)
-    x = xs.todense()
-
-    assert_eq(func(x, y), func(xs, ys))
-
-
-@pytest.mark.parametrize('func', [
-    operator.mul,
-    operator.add,
-    operator.sub,
-    pytest.mark.xfail(operator.gt, reason='Scipy sparse doesn\'t support this yet.'),
-    pytest.mark.xfail(operator.lt, reason='Scipy sparse doesn\'t support this yet.'),
-    pytest.mark.xfail(operator.ne, reason='Scipy sparse doesn\'t support this yet.'),
-])
-def test_op_scipy_sparse_left(func):
-    ys = sparse.random((3, 4), density=0.5)
-    x = sparse.random((3, 4), density=0.5).todense()
-
-    xs = scipy.sparse.csr_matrix(x)
-    y = ys.todense()
-
-    assert_eq(func(x, y), func(xs, ys))
-
-
 @pytest.mark.parametrize('func, scalar', [
     (operator.mul, 5),
     (operator.add, 0),

From e38f548ecff90fe2e016eff0b7540de1a00b0eb4 Mon Sep 17 00:00:00 2001
From: Hameer Abbasi <hameerabbasi@yahoo.com>
Date: Fri, 19 Jan 2018 10:18:36 +0100
Subject: [PATCH 4/9] Add back pure Python abs support.

---
 sparse/coo.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/sparse/coo.py b/sparse/coo.py
index f1b3e3f6..ef92b17d 100644
--- a/sparse/coo.py
+++ b/sparse/coo.py
@@ -1629,6 +1629,8 @@ def abs(self):
         """
         return self.elemwise(abs)
 
+    __abs__ = abs
+
     def exp(self, out=None):
         """
         Calculate the exponential of all elements in the array.

From 3951ac5b2537b185e643704081f4b94678c612f6 Mon Sep 17 00:00:00 2001
From: Hameer Abbasi <hameerabbasi@yahoo.com>
Date: Tue, 23 Jan 2018 16:13:50 +0100
Subject: [PATCH 5/9] Drop Scipy op support

---
 sparse/coo.py | 2 --
 1 file changed, 2 deletions(-)

diff --git a/sparse/coo.py b/sparse/coo.py
index ef92b17d..f7978ea4 100644
--- a/sparse/coo.py
+++ b/sparse/coo.py
@@ -1537,8 +1537,6 @@ def _elemwise(func, *args, **kwargs):
                                  and self.ndim == 0):
             func = partial(func, self)
             other = args[1]
-            if isinstance(other, scipy.sparse.spmatrix):
-                other = COO.from_scipy_sparse(other)
             return _elemwise_unary(func, other, *args[2:], **kwargs)
 
         if len(args) == 1:

From 4809648c894c6ac2bc6df84d0b5921c5f3690f0f Mon Sep 17 00:00:00 2001
From: Hameer Abbasi <hameerabbasi@yahoo.com>
Date: Thu, 25 Jan 2018 13:45:03 +0100
Subject: [PATCH 6/9] Add Scipy sparse support back.

---
 sparse/coo.py            | 12 ++++++++----
 sparse/tests/test_coo.py | 32 ++++++++++++++++++++++++++++++++
 2 files changed, 40 insertions(+), 4 deletions(-)

diff --git a/sparse/coo.py b/sparse/coo.py
index f7978ea4..22b048c8 100644
--- a/sparse/coo.py
+++ b/sparse/coo.py
@@ -1539,11 +1539,17 @@ def _elemwise(func, *args, **kwargs):
             other = args[1]
             return _elemwise_unary(func, other, *args[2:], **kwargs)
 
+        if isinstance(self, scipy.sparse.spmatrix):
+            self = COO.from_scipy_sparse(self)
+
         if len(args) == 1:
             return _elemwise_unary(func, self, *args[1:], **kwargs)
         else:
             other = args[1]
 
+            if isinstance(other, scipy.sparse.spmatrix):
+                other = COO.from_scipy_sparse(other)
+
             if isinstance(other, COO) or isinstance(other, np.ndarray):
                 return _elemwise_binary(func, self, other, *args[2:], **kwargs)
             else:
@@ -1625,9 +1631,7 @@ def abs(self):
         --------
         :obj:`numpy.absolute` : NumPy equivalent ufunc.
         """
-        return self.elemwise(abs)
-
-    __abs__ = abs
+        return self.elemwise(np.abs)
 
     def exp(self, out=None):
         """
@@ -1909,7 +1913,7 @@ def astype(self, dtype, out=None):
         actually supported.
         """
         assert out is None
-        return self.elemwise(np.ndarray.astype, dtype)
+        return self.elemwise(np.ndarray.astype, dtype=dtype)
 
     def maybe_densify(self, max_size=1000, min_density=0.25):
         """
diff --git a/sparse/tests/test_coo.py b/sparse/tests/test_coo.py
index d270af42..ae3889ca 100644
--- a/sparse/tests/test_coo.py
+++ b/sparse/tests/test_coo.py
@@ -894,6 +894,38 @@ def test_scipy_sparse_interaction(scipy_format):
     assert_eq(sp, coo)
 
 
+@pytest.mark.parametrize('func', [
+    operator.mul, operator.add, operator.sub, operator.gt,
+    operator.lt, operator.ne
+])
+def test_op_scipy_sparse(func):
+    xs = sparse.random((3, 4), density=0.5)
+    y = sparse.random((3, 4), density=0.5).todense()
+
+    ys = scipy.sparse.csr_matrix(y)
+    x = xs.todense()
+
+    assert_eq(func(x, y), func(xs, ys))
+
+
+@pytest.mark.parametrize('func', [
+    operator.add,
+    operator.sub,
+    pytest.mark.xfail(operator.mul, reason='Scipy sparse auto-densifies in this case.'),
+    pytest.mark.xfail(operator.gt, reason='Scipy sparse doesn\'t support this yet.'),
+    pytest.mark.xfail(operator.lt, reason='Scipy sparse doesn\'t support this yet.'),
+    pytest.mark.xfail(operator.ne, reason='Scipy sparse doesn\'t support this yet.'),
+])
+def test_op_scipy_sparse_left(func):
+    ys = sparse.random((3, 4), density=0.5)
+    x = sparse.random((3, 4), density=0.5).todense()
+
+    xs = scipy.sparse.csr_matrix(x)
+    y = ys.todense()
+
+    assert_eq(func(x, y), func(xs, ys))
+
+
 def test_cache_csr():
     x = sparse.random((10, 5), density=0.5).todense()
     s = COO(x, cache=True)

From 5ccdbaa93113e87c07e270478cc75944d8dda487 Mon Sep 17 00:00:00 2001
From: Hameer Abbasi <hameerabbasi@yahoo.com>
Date: Thu, 25 Jan 2018 16:41:22 +0100
Subject: [PATCH 7/9] Update docs.

---
 docs/user_manual/operations/operators.rst | 25 ++++++++++++++++++++++-
 1 file changed, 24 insertions(+), 1 deletion(-)

diff --git a/docs/user_manual/operations/operators.rst b/docs/user_manual/operations/operators.rst
index 47c4c635..1372854b 100644
--- a/docs/user_manual/operations/operators.rst
+++ b/docs/user_manual/operations/operators.rst
@@ -73,6 +73,26 @@ The following is true so long as there are no infinities or NaNs in :code:`x`:
 In general, if operating on the :code:`numpy.ndarray` with a zero would produce
 all-zeros then the operation is supported.
 
+Operations with :obj:`scipy.sparse.spmatrix`
+--------------------------------------------
+Certain operations with :obj:`scipy.sparse.spmatrix` are also supported.
+For example, the following are all allowed if :code:`y` is a :obj:`scipy.sparse.spmatrix`:
+
+.. code-block:: python
+
+   x + y
+   x - y
+   x * y
+   x > y
+   x < y
+
+In general, if operating on a :code:`scipy.sparse.spmatrix` is the same as operating
+on :obj:`COO`, as long as it is to the right of the operator.
+
+.. note:: Results are not guaranteed if :code:`x` is a :obj:`scipy.sparse.spmatrix`.
+   For this reason, we recommend that all Scipy sparse matrices should be explicitly
+   converted to :obj:`COO` before any operations.
+
 Broadcasting
 ------------
 All binary operators support :obj:`broadcasting <numpy.doc.broadcasting>`.
@@ -88,7 +108,8 @@ Full List of Operators
 ----------------------
 Here, :code:`x` and :code:`y` can be :obj:`COO` arrays,
 :obj:`numpy.ndarray` objects or scalars, keeping in mind :ref:`auto
-densification rules <auto-densification>`. The following operators are supported:
+densification rules <auto-densification>`. In addition, :code:`y` can also
+be a :obj:`scipy.sparse.spmatrix` The following operators are supported:
 
 * Basic algebraic operations
 
@@ -119,3 +140,5 @@ densification rules <auto-densification>`. The following operators are supported
 
    * :obj:`operator.lshift` (:code:`x << y`)
    * :obj:`operator.rshift` (:code:`x >> y`)
+
+.. note:: In-place operators are not supported at this time.

From 3a92642fbe4db2779829c0c5c8511235efdf095c Mon Sep 17 00:00:00 2001
From: Hameer Abbasi <hameerabbasi@yahoo.com>
Date: Fri, 26 Jan 2018 21:33:03 +0100
Subject: [PATCH 8/9] Remove most .ufunc calls since Numpy doesn't have them.

---
 sparse/coo.py | 255 --------------------------------------------------
 1 file changed, 255 deletions(-)

diff --git a/sparse/coo.py b/sparse/coo.py
index 22b048c8..4a56ce05 100644
--- a/sparse/coo.py
+++ b/sparse/coo.py
@@ -1623,202 +1623,6 @@ def broadcast_to(self, shape):
         return COO(coords, data, shape=result_shape, has_duplicates=self.has_duplicates,
                    sorted=self.sorted)
 
-    def abs(self):
-        """
-        Calculate the absolute value element-wise.
-
-        See also
-        --------
-        :obj:`numpy.absolute` : NumPy equivalent ufunc.
-        """
-        return self.elemwise(np.abs)
-
-    def exp(self, out=None):
-        """
-        Calculate the exponential of all elements in the array.
-
-        See also
-        --------
-        :obj:`numpy.exp` : NumPy equivalent ufunc.
-        :obj:`COO.elemwise`: Apply an arbitrary element-wise function to one or two
-            arguments.
-
-        Notes
-        -----
-        The :code:`out` parameter is provided just for compatibility with Numpy and isn't
-        actually supported.
-        """
-        assert out is None
-        return self.elemwise(np.exp)
-
-    def expm1(self, out=None):
-        """
-        Calculate :code:`exp(x) - 1` for all elements in the array.
-
-        See also
-        --------
-        scipy.sparse.coo_matrix.expm1 : SciPy sparse equivalent function
-        :obj:`numpy.expm1` : NumPy equivalent ufunc.
-        :obj:`COO.elemwise`: Apply an arbitrary element-wise function to one or two
-            arguments.
-
-        Notes
-        -----
-        The :code:`out` parameter is provided just for compatibility with Numpy and isn't
-        actually supported.
-        """
-        assert out is None
-        return self.elemwise(np.expm1)
-
-    def log1p(self, out=None):
-        """
-        Return the natural logarithm of one plus the input array, element-wise.
-
-        Calculates :code:`log(1 + x)`.
-
-        See also
-        --------
-        scipy.sparse.coo_matrix.log1p : SciPy sparse equivalent function
-        :obj:`numpy.log1p` : NumPy equivalent ufunc.
-        :obj:`COO.elemwise`: Apply an arbitrary element-wise function to one or two
-            arguments.
-
-        Notes
-        -----
-        The :code:`out` parameter is provided just for compatibility with Numpy and isn't
-        actually supported.
-        """
-        assert out is None
-        return self.elemwise(np.log1p)
-
-    def sin(self, out=None):
-        """
-        Trigonometric sine, element-wise.
-
-        See also
-        --------
-        scipy.sparse.coo_matrix.sin : SciPy sparse equivalent function
-        :obj:`numpy.sin` : NumPy equivalent ufunc.
-        :obj:`COO.elemwise`: Apply an arbitrary element-wise function to one or two
-            arguments.
-
-        Notes
-        -----
-        The :code:`out` parameter is provided just for compatibility with Numpy and isn't
-        actually supported.
-        """
-        assert out is None
-        return self.elemwise(np.sin)
-
-    def sinh(self, out=None):
-        """
-        Hyperbolic sine, element-wise.
-
-        See also
-        --------
-        scipy.sparse.coo_matrix.sinh : SciPy sparse equivalent function
-        :obj:`numpy.sinh` : NumPy equivalent ufunc.
-        :obj:`COO.elemwise`: Apply an arbitrary element-wise function to one or two
-            arguments.
-
-        Notes
-        -----
-        The :code:`out` parameter is provided just for compatibility with Numpy and isn't
-        actually supported.
-        """
-        assert out is None
-        return self.elemwise(np.sinh)
-
-    def tan(self, out=None):
-        """
-        Compute tangent element-wise.
-
-        See also
-        --------
-        scipy.sparse.coo_matrix.tan : SciPy sparse equivalent function
-        :obj:`numpy.tan` : NumPy equivalent ufunc.
-        :obj:`COO.elemwise`: Apply an arbitrary element-wise function to one or two
-            arguments.
-        """
-        assert out is None
-        return self.elemwise(np.tan)
-
-    def tanh(self, out=None):
-        """
-        Compute hyperbolic tangent element-wise.
-
-        See also
-        --------
-        scipy.sparse.coo_matrix.tanh : SciPy sparse equivalent function
-        :obj:`numpy.tanh` : NumPy equivalent ufunc.
-        :obj:`COO.elemwise`: Apply an arbitrary element-wise function to one or two
-            arguments.
-
-        Notes
-        -----
-        The :code:`out` parameter is provided just for compatibility with Numpy and isn't
-        actually supported.
-        """
-        assert out is None
-        return self.elemwise(np.tanh)
-
-    def sqrt(self, out=None):
-        """
-        Return the positive square-root of an array, element-wise.
-
-        See also
-        --------
-        scipy.sparse.coo_matrix.sqrt : SciPy sparse equivalent function
-        :obj:`numpy.sqrt` : NumPy equivalent ufunc.
-        :obj:`COO.elemwise`: Apply an arbitrary element-wise function to one or two
-            arguments.
-
-        Notes
-        -----
-        The :code:`out` parameter is provided just for compatibility with Numpy and isn't
-        actually supported.
-        """
-        assert out is None
-        return self.elemwise(np.sqrt)
-
-    def ceil(self, out=None):
-        """
-        Return the ceiling of the input, element-wise.
-
-        See also
-        --------
-        scipy.sparse.coo_matrix.ceil : SciPy sparse equivalent function
-        :obj:`numpy.ceil` : NumPy equivalent ufunc.
-        :obj:`COO.elemwise`: Apply an arbitrary element-wise function to one or two
-            arguments.
-
-        Notes
-        -----
-        The :code:`out` parameter is provided just for compatibility with Numpy and isn't
-        actually supported.
-        """
-        assert out is None
-        return self.elemwise(np.ceil)
-
-    def floor(self, out=None):
-        """
-        Return the floor of the input, element-wise.
-
-        See also
-        --------
-        scipy.sparse.coo_matrix.floor : SciPy sparse equivalent function
-        :obj:`numpy.floor` : NumPy equivalent ufunc.
-        :obj:`COO.elemwise`: Apply an arbitrary element-wise function to one or two
-            arguments.
-
-        Notes
-        -----
-        The :code:`out` parameter is provided just for compatibility with Numpy and isn't
-        actually supported.
-        """
-        assert out is None
-        return self.elemwise(np.floor)
-
     def round(self, decimals=0, out=None):
         """
         Evenly round to the given number of decimals.
@@ -1837,65 +1641,6 @@ def round(self, decimals=0, out=None):
         assert out is None
         return self.elemwise(np.round, decimals)
 
-    def rint(self, out=None):
-        """
-        Round elements of the array to the nearest integer.
-
-        See also
-        --------
-        scipy.sparse.coo_matrix.rint : SciPy sparse equivalent function
-        :obj:`numpy.rint` : NumPy equivalent ufunc.
-        :obj:`COO.elemwise`: Apply an arbitrary element-wise function to one or two
-            arguments.
-
-        Notes
-        -----
-        The :code:`out` parameter is provided just for compatibility with Numpy and isn't
-        actually supported.
-        """
-        assert out is None
-        return self.elemwise(np.rint)
-
-    def conj(self, out=None):
-        """
-        Return the complex conjugate, element-wise.
-
-        See also
-        --------
-        conjugate : Equivalent function
-        scipy.sparse.coo_matrix.conj : SciPy sparse equivalent function
-        :obj:`numpy.conj` : NumPy equivalent ufunc.
-        :obj:`COO.elemwise`: Apply an arbitrary element-wise function to one or two
-            arguments.
-
-        Notes
-        -----
-        The :code:`out` parameter is provided just for compatibility with Numpy and isn't
-        actually supported.
-        """
-        assert out is None
-        return self.elemwise(np.conj)
-
-    def conjugate(self, out=None):
-        """
-        Return the complex conjugate, element-wise.
-
-        See also
-        --------
-        conj : Equivalent function
-        scipy.sparse.coo_matrix.conjugate : SciPy sparse equivalent function
-        :obj:`numpy.conj` : NumPy equivalent ufunc.
-        :obj:`COO.elemwise`: Apply an arbitrary element-wise function to one or two
-            arguments.
-
-        Notes
-        -----
-        The :code:`out` parameter is provided just for compatibility with Numpy and isn't
-        actually supported.
-        """
-        assert out is None
-        return self.elemwise(np.conjugate)
-
     def astype(self, dtype, out=None):
         """
         Copy of the array, cast to a specified type.

From 316022d6d927234185277046313e43a003ea5eca Mon Sep 17 00:00:00 2001
From: Hameer Abbasi <hameerabbasi@yahoo.com>
Date: Fri, 26 Jan 2018 21:45:11 +0100
Subject: [PATCH 9/9] Update docs.

---
 docs/generated/sparse.COO.abs.rst        |  6 -----
 docs/generated/sparse.COO.ceil.rst       |  6 -----
 docs/generated/sparse.COO.conj.rst       |  6 -----
 docs/generated/sparse.COO.conjugate.rst  |  6 -----
 docs/generated/sparse.COO.exp.rst        |  6 -----
 docs/generated/sparse.COO.expm1.rst      |  6 -----
 docs/generated/sparse.COO.floor.rst      |  6 -----
 docs/generated/sparse.COO.log1p.rst      |  6 -----
 docs/generated/sparse.COO.rint.rst       |  6 -----
 docs/generated/sparse.COO.rst            | 14 ------------
 docs/generated/sparse.COO.sin.rst        |  6 -----
 docs/generated/sparse.COO.sinh.rst       |  6 -----
 docs/generated/sparse.COO.sqrt.rst       |  6 -----
 docs/generated/sparse.COO.tan.rst        |  6 -----
 docs/generated/sparse.COO.tanh.rst       |  6 -----
 docs/user_manual/operations/elemwise.rst | 29 ++++--------------------
 16 files changed, 4 insertions(+), 123 deletions(-)
 delete mode 100644 docs/generated/sparse.COO.abs.rst
 delete mode 100644 docs/generated/sparse.COO.ceil.rst
 delete mode 100644 docs/generated/sparse.COO.conj.rst
 delete mode 100644 docs/generated/sparse.COO.conjugate.rst
 delete mode 100644 docs/generated/sparse.COO.exp.rst
 delete mode 100644 docs/generated/sparse.COO.expm1.rst
 delete mode 100644 docs/generated/sparse.COO.floor.rst
 delete mode 100644 docs/generated/sparse.COO.log1p.rst
 delete mode 100644 docs/generated/sparse.COO.rint.rst
 delete mode 100644 docs/generated/sparse.COO.sin.rst
 delete mode 100644 docs/generated/sparse.COO.sinh.rst
 delete mode 100644 docs/generated/sparse.COO.sqrt.rst
 delete mode 100644 docs/generated/sparse.COO.tan.rst
 delete mode 100644 docs/generated/sparse.COO.tanh.rst

diff --git a/docs/generated/sparse.COO.abs.rst b/docs/generated/sparse.COO.abs.rst
deleted file mode 100644
index 7bfba439..00000000
--- a/docs/generated/sparse.COO.abs.rst
+++ /dev/null
@@ -1,6 +0,0 @@
-COO\.abs
-========
-
-.. currentmodule:: sparse
-
-.. automethod:: COO.abs
\ No newline at end of file
diff --git a/docs/generated/sparse.COO.ceil.rst b/docs/generated/sparse.COO.ceil.rst
deleted file mode 100644
index e999de48..00000000
--- a/docs/generated/sparse.COO.ceil.rst
+++ /dev/null
@@ -1,6 +0,0 @@
-COO\.ceil
-=========
-
-.. currentmodule:: sparse
-
-.. automethod:: COO.ceil
\ No newline at end of file
diff --git a/docs/generated/sparse.COO.conj.rst b/docs/generated/sparse.COO.conj.rst
deleted file mode 100644
index 39a963af..00000000
--- a/docs/generated/sparse.COO.conj.rst
+++ /dev/null
@@ -1,6 +0,0 @@
-COO\.conj
-=========
-
-.. currentmodule:: sparse
-
-.. automethod:: COO.conj
\ No newline at end of file
diff --git a/docs/generated/sparse.COO.conjugate.rst b/docs/generated/sparse.COO.conjugate.rst
deleted file mode 100644
index 476903c1..00000000
--- a/docs/generated/sparse.COO.conjugate.rst
+++ /dev/null
@@ -1,6 +0,0 @@
-COO\.conjugate
-==============
-
-.. currentmodule:: sparse
-
-.. automethod:: COO.conjugate
\ No newline at end of file
diff --git a/docs/generated/sparse.COO.exp.rst b/docs/generated/sparse.COO.exp.rst
deleted file mode 100644
index 7a6067ef..00000000
--- a/docs/generated/sparse.COO.exp.rst
+++ /dev/null
@@ -1,6 +0,0 @@
-COO\.exp
-========
-
-.. currentmodule:: sparse
-
-.. automethod:: COO.exp
\ No newline at end of file
diff --git a/docs/generated/sparse.COO.expm1.rst b/docs/generated/sparse.COO.expm1.rst
deleted file mode 100644
index 46717d78..00000000
--- a/docs/generated/sparse.COO.expm1.rst
+++ /dev/null
@@ -1,6 +0,0 @@
-COO\.expm1
-==========
-
-.. currentmodule:: sparse
-
-.. automethod:: COO.expm1
\ No newline at end of file
diff --git a/docs/generated/sparse.COO.floor.rst b/docs/generated/sparse.COO.floor.rst
deleted file mode 100644
index 7ff8a946..00000000
--- a/docs/generated/sparse.COO.floor.rst
+++ /dev/null
@@ -1,6 +0,0 @@
-COO\.floor
-==========
-
-.. currentmodule:: sparse
-
-.. automethod:: COO.floor
\ No newline at end of file
diff --git a/docs/generated/sparse.COO.log1p.rst b/docs/generated/sparse.COO.log1p.rst
deleted file mode 100644
index ec27f8e4..00000000
--- a/docs/generated/sparse.COO.log1p.rst
+++ /dev/null
@@ -1,6 +0,0 @@
-COO\.log1p
-==========
-
-.. currentmodule:: sparse
-
-.. automethod:: COO.log1p
\ No newline at end of file
diff --git a/docs/generated/sparse.COO.rint.rst b/docs/generated/sparse.COO.rint.rst
deleted file mode 100644
index 4302f0d4..00000000
--- a/docs/generated/sparse.COO.rint.rst
+++ /dev/null
@@ -1,6 +0,0 @@
-COO\.rint
-=========
-
-.. currentmodule:: sparse
-
-.. automethod:: COO.rint
\ No newline at end of file
diff --git a/docs/generated/sparse.COO.rst b/docs/generated/sparse.COO.rst
index 078b2846..2da5bcf3 100644
--- a/docs/generated/sparse.COO.rst
+++ b/docs/generated/sparse.COO.rst
@@ -33,22 +33,8 @@ COO
       :toctree:
 
       COO.elemwise
-      COO.abs
       COO.astype
-      COO.ceil
-      COO.conj
-      COO.conjugate
-      COO.exp
-      COO.expm1
-      COO.floor
-      COO.log1p
-      COO.rint
       COO.round
-      COO.sin
-      COO.sinh
-      COO.sqrt
-      COO.tan
-      COO.tanh
 
    .. rubric:: :doc:`Reductions <../user_manual/operations/reductions>`
    .. autosummary::
diff --git a/docs/generated/sparse.COO.sin.rst b/docs/generated/sparse.COO.sin.rst
deleted file mode 100644
index 2c00972b..00000000
--- a/docs/generated/sparse.COO.sin.rst
+++ /dev/null
@@ -1,6 +0,0 @@
-COO\.sin
-========
-
-.. currentmodule:: sparse
-
-.. automethod:: COO.sin
\ No newline at end of file
diff --git a/docs/generated/sparse.COO.sinh.rst b/docs/generated/sparse.COO.sinh.rst
deleted file mode 100644
index e3d5b7f0..00000000
--- a/docs/generated/sparse.COO.sinh.rst
+++ /dev/null
@@ -1,6 +0,0 @@
-COO\.sinh
-=========
-
-.. currentmodule:: sparse
-
-.. automethod:: COO.sinh
\ No newline at end of file
diff --git a/docs/generated/sparse.COO.sqrt.rst b/docs/generated/sparse.COO.sqrt.rst
deleted file mode 100644
index 10a8ccb2..00000000
--- a/docs/generated/sparse.COO.sqrt.rst
+++ /dev/null
@@ -1,6 +0,0 @@
-COO\.sqrt
-=========
-
-.. currentmodule:: sparse
-
-.. automethod:: COO.sqrt
\ No newline at end of file
diff --git a/docs/generated/sparse.COO.tan.rst b/docs/generated/sparse.COO.tan.rst
deleted file mode 100644
index f91eb510..00000000
--- a/docs/generated/sparse.COO.tan.rst
+++ /dev/null
@@ -1,6 +0,0 @@
-COO\.tan
-========
-
-.. currentmodule:: sparse
-
-.. automethod:: COO.tan
\ No newline at end of file
diff --git a/docs/generated/sparse.COO.tanh.rst b/docs/generated/sparse.COO.tanh.rst
deleted file mode 100644
index db166d9a..00000000
--- a/docs/generated/sparse.COO.tanh.rst
+++ /dev/null
@@ -1,6 +0,0 @@
-COO\.tanh
-=========
-
-.. currentmodule:: sparse
-
-.. automethod:: COO.tanh
\ No newline at end of file
diff --git a/docs/user_manual/operations/elemwise.rst b/docs/user_manual/operations/elemwise.rst
index b54e26fa..a1f2127f 100644
--- a/docs/user_manual/operations/elemwise.rst
+++ b/docs/user_manual/operations/elemwise.rst
@@ -10,18 +10,18 @@ To illustrate, the following are all possible, and will produce another
 
 .. code-block:: python
 
-   x.abs()
+   np.abs(x)
    np.sin(x)
    np.sqrt(x)
-   x.conj()
-   x.expm1()
+   np.conj(x)
+   np.expm1(x)
    np.log1p(x)
 
 However, the following are all unsupported and will raise a :obj:`ValueError`:
 
 .. code-block:: python
 
-   x.exp()
+   np.exp(x)
    np.cos(x)
    np.log(x)
 
@@ -41,24 +41,3 @@ a :obj:`numpy.ndarray`. For example, the following will add two
 
    x.elemwise(np.add, y)
 
-Partial List of Supported :obj:`numpy.ufunc` s
-----------------------------------------------
-Although any unary or binary :obj:`numpy.ufunc` should work if the result is
-not dense, when calling in the form :code:`x.func()`, the following operations
-are supported:
-
-* :obj:`COO.abs`
-* :obj:`COO.expm1`
-* :obj:`COO.log1p`
-* :obj:`COO.sin`
-* :obj:`COO.sinh`
-* :obj:`COO.tan`
-* :obj:`COO.tanh`
-* :obj:`COO.sqrt`
-* :obj:`COO.ceil`
-* :obj:`COO.floor`
-* :obj:`COO.round`
-* :obj:`COO.rint`
-* :obj:`COO.conj`
-* :obj:`COO.conjugate`
-* :obj:`COO.astype`