[Numpy] add isposinf isneginf isfinite

python/mxnet/ndarray/numpy/_op.py

@@ -44,7 +44,8 @@
            'tril', 'identity', 'take', 'ldexp', 'vdot', 'inner', 'outer',
            'equal', 'not_equal', 'greater', 'less', 'greater_equal', 'less_equal', 'hsplit', 'rot90', 'einsum',
            'true_divide', 'nonzero', 'quantile', 'percentile', 'shares_memory', 'may_share_memory',
-           'diff', 'resize', 'polyval', 'nan_to_num', 'isnan', 'isinf', 'where', 'bincount']
+           'diff', 'resize', 'polyval', 'nan_to_num', 'isnan', 'isinf', 'isposinf', 'isneginf', 'isfinite',
+           'where', 'bincount']
 
 
 @set_module('mxnet.ndarray.numpy')
@@ -6759,9 +6760,8 @@ def isnan(x, out=None, **kwargs):
     Notes
     -----
     NumPy uses the IEEE Standard for Binary Floating-Point for Arithmetic (IEEE 754).
-    This means that Not a Number is not equivalent to infinity.
 
-    This function differs from the original `numpy.isnan
+    This function differs from the original `numpy.isinf
     <https://docs.scipy.org/doc/numpy/reference/generated/numpy.isnan.html>`_ in
     the following aspects:
     - Does not support complex number for now
@@ -6835,6 +6835,152 @@ def isinf(x, out=None, **kwargs):
     return _unary_func_helper(x, _npi.isinf, _np.isinf, out=out, **kwargs)
 
 
+@wrap_np_unary_func
+def isposinf(x, out=None, **kwargs):
+    """
+    Test element-wise for positive infinity, return result as bool array.
+
+    Parameters
+    ----------
+    x : ndarray
+        Input array.
+    out : ndarray or None, optional
+        A location into which the result is stored.
+        If provided, it must have the same shape and dtype as input ndarray.
+        If not provided or `None`, a freshly-allocated array is returned.
+
+    Returns
+    -------
+    y : ndarray or bool
+        True where x is positive infinity, false otherwise.
+        This is a scalar if x is a scalar.
+
+    Notes
+    -----
+    NumPy uses the IEEE Standard for Binary Floating-Point for Arithmetic (IEEE 754).
+    This means that Not a Number is not equivalent to infinity.
+
+    Examples
+    --------
+    >>> np.isposinf(np.inf)
+    True
+    >>> np.isposinf(-np.inf)
+    False
+    >>> np.isposinf(np.nan)
+    False
+    >>> np.isposinf(np.array([-np.inf, 0., np.inf]))
+    array([False, False,  True])
+    >>> x = np.array([-np.inf, 0., np.inf])
+    >>> y = np.array([True, True, True], dtype=np.bool)
+    >>> np.isposinf(x, y)
+    array([False, False,  True])
+    >>> y
+    array([False, False,  True])
+    """
+    return _unary_func_helper(x, _npi.isposinf, _np.isposinf, out=out, **kwargs)
+
+
+@set_module('mxnet.ndarray.numpy')
+@wrap_np_unary_func
+def isneginf(x, out=None, **kwargs):
+    """
+    Test element-wise for negative infinity, return result as bool array.
+
+    Parameters
+    ----------
+    x : ndarray
+        Input array.
+    out : ndarray or None, optional
+        A location into which the result is stored.
+        If provided, it must have the same shape and dtype as input ndarray.
+        If not provided or `None`, a freshly-allocated array is returned.
+
+    Returns
+    -------
+    y : ndarray or bool
+        True where x is negative infinity, false otherwise.
+        This is a scalar if x is a scalar.
+
+    Notes
+    -----
+    NumPy uses the IEEE Standard for Binary Floating-Point for Arithmetic (IEEE 754).
+    This means that Not a Number is not equivalent to infinity.
+
+    Examples
+    --------
+    >>> np.isneginf(-np.inf)
+    True
+    >>> np.isneginf(np.inf)
+    False
+    >>> np.isneginf(float('-inf'))
+    True
+    >>> np.isneginf(np.array([-np.inf, 0., np.inf]))
+    array([ True, False, False])
+    >>> x = np.array([-np.inf, 0., np.inf])
+    >>> y = np.array([True, True, True], dtype=np.bool)
+    >>> np.isneginf(x, y)
+    array([ True, False, False])
+    >>> y
+    array([ True, False, False])
+    """
+    return _unary_func_helper(x, _npi.isneginf, _np.isneginf, out=out, **kwargs)
+
+
+@set_module('mxnet.ndarray.numpy')
+@wrap_np_unary_func
+def isfinite(x, out=None, **kwargs):
+    """
+    Test element-wise for finiteness (not infinity or not Not a Number).
+
+    Parameters
+    ----------
+    x : ndarray
+        Input array.
+    out : ndarray or None, optional
+        A location into which the result is stored.
+        If provided, it must have the same shape and dtype as input ndarray.
+        If not provided or `None`, a freshly-allocated array is returned.
+
+    Returns
+    -------
+    y : ndarray or bool
+        True where x is negative infinity, false otherwise.
+        This is a scalar if x is a scalar.
+
+    Notes
+    -----
+    Not a Number, positive infinity and negative infinity are considered to be non-finite.
+
+    NumPy uses the IEEE Standard for Binary Floating-Point for Arithmetic (IEEE 754).
+    This means that Not a Number is not equivalent to infinity.
+    Also that positive infinity is not equivalent to negative infinity.
+    But infinity is equivalent to positive infinity. Errors result if the second argument
+    is also supplied when x is a scalar input, or if first and second arguments have different shapes.
+
+    Examples
+    --------
+    >>> np.isfinite(1)
+    True
+    >>> np.isfinite(0)
+    True
+    >>> np.isfinite(np.nan)
+    False
+    >>> np.isfinite(np.inf)
+    False
+    >>> np.isfinite(-np.inf)
+    False
+    >>> np.isfinite(np.array([np.log(-1.),1.,np.log(0)]))
+    array([False,  True, False])
+    >>> x = np.array([-np.inf, 0., np.inf])
+    >>> y = np.array([True, True, True], dtype=np.bool)
+    >>> np.isfinite(x, y)
+    array([False,  True, False])
+    >>> y
+    array([False,  True, False])
+    """
+    return _unary_func_helper(x, _npi.isfinite, _np.isfinite, out=out, **kwargs)
+
+
 @set_module('mxnet.ndarray.numpy')
 def where(condition, x=None, y=None):  # pylint: disable=too-many-return-statements
     """where(condition, [x, y])

python/mxnet/numpy/multiarray.py

@@ -65,7 +65,7 @@
            'unique', 'lcm', 'tril', 'identity', 'take', 'ldexp', 'vdot', 'inner', 'outer', 'equal', 'not_equal',
            'greater', 'less', 'greater_equal', 'less_equal', 'hsplit', 'rot90', 'einsum', 'true_divide', 'nonzero',
            'quantile', 'percentile', 'shares_memory', 'may_share_memory', 'diff', 'resize', 'matmul',
-           'nan_to_num', 'isnan', 'isinf', 'polyval', 'where', 'bincount']
+           'nan_to_num', 'isnan', 'isinf', 'isposinf', 'isneginf', 'isfinite', 'polyval', 'where', 'bincount']
 
 __all__ += fallback.__all__
 
@@ -8827,9 +8827,8 @@ def isnan(x, out=None, **kwargs):
     Notes
     -----
     NumPy uses the IEEE Standard for Binary Floating-Point for Arithmetic (IEEE 754).
-    This means that Not a Number is not equivalent to infinity.
 
-    This function differs from the original `numpy.isnan
+    This function differs from the original `numpy.isinf
     <https://docs.scipy.org/doc/numpy/reference/generated/numpy.isnan.html>`_ in
     the following aspects:
     - Does not support complex number for now
@@ -8903,6 +8902,153 @@ def isinf(x, out=None, **kwargs):
     return _mx_nd_np.isinf(x, out=out, **kwargs)
 
 
+@set_module('mxnet.ndarray.numpy')
+@wrap_np_unary_func
+def isposinf(x, out=None, **kwargs):
+    """
+    Test element-wise for positive infinity, return result as bool array.
+
+    Parameters
+    ----------
+    x : ndarray
+        Input array.
+    out : ndarray or None, optional
+        A location into which the result is stored.
+        If provided, it must have the same shape and dtype as input ndarray.
+        If not provided or `None`, a freshly-allocated array is returned.
+
+    Returns
+    -------
+    y : ndarray or bool
+        True where x is positive infinity, false otherwise.
+        This is a scalar if x is a scalar.
+
+    Notes
+    -----
+    NumPy uses the IEEE Standard for Binary Floating-Point for Arithmetic (IEEE 754).
+    This means that Not a Number is not equivalent to infinity.
+
+    Examples
+    --------
+    >>> np.isposinf(np.inf)
+    True
+    >>> np.isposinf(-np.inf)
+    False
+    >>> np.isposinf(np.nan)
+    False
+    >>> np.isposinf(np.array([-np.inf, 0., np.inf]))
+    array([False, False,  True])
+    >>> x = np.array([-np.inf, 0., np.inf])
+    >>> y = np.array([True, True, True], dtype=np.bool)
+    >>> np.isposinf(x, y)
+    array([False, False,  True])
+    >>> y
+    array([False, False,  True])
+    """
+    return _mx_nd_np.isposinf(x, out=out, **kwargs)
+
+
+@set_module('mxnet.numpy')
+@wrap_np_unary_func
+def isneginf(x, out=None, **kwargs):
+    """
+    Test element-wise for negative infinity, return result as bool array.
+
+    Parameters
+    ----------
+    x : ndarray
+        Input array.
+    out : ndarray or None, optional
+        A location into which the result is stored.
+        If provided, it must have the same shape and dtype as input ndarray.
+        If not provided or `None`, a freshly-allocated array is returned.
+
+    Returns
+    -------
+    y : ndarray or bool
+        True where x is negative infinity, false otherwise.
+        This is a scalar if x is a scalar.
+
+    Notes
+    -----
+    NumPy uses the IEEE Standard for Binary Floating-Point for Arithmetic (IEEE 754).
+    This means that Not a Number is not equivalent to infinity.
+
+    Examples
+    --------
+    >>> np.isneginf(-np.inf)
+    True
+    >>> np.isneginf(np.inf)
+    False
+    >>> np.isneginf(float('-inf'))
+    True
+    >>> np.isneginf(np.array([-np.inf, 0., np.inf]))
+    array([ True, False, False])
+    >>> x = np.array([-np.inf, 0., np.inf])
+    >>> y = np.array([True, True, True], dtype=np.bool)
+    >>> np.isneginf(x, y)
+    array([ True, False, False])
+    >>> y
+    array([ True, False, False])
+    """
+    return _mx_nd_np.isneginf(x, out=out, **kwargs)
+
+
+@set_module('mxnet.numpy')
+@wrap_np_unary_func
+def isfinite(x, out=None, **kwargs):
+    """
+    Test element-wise for finiteness (not infinity or not Not a Number).
+
+    Parameters
+    ----------
+    x : ndarray
+        Input array.
+    out : ndarray or None, optional
+        A location into which the result is stored.
+        If provided, it must have the same shape and dtype as input ndarray.
+        If not provided or `None`, a freshly-allocated array is returned.
+
+    Returns
+    -------
+    y : ndarray or bool
+        True where x is negative infinity, false otherwise.
+        This is a scalar if x is a scalar.
+
+    Notes
+    -----
+    Not a Number, positive infinity and negative infinity are considered to be non-finite.
+
+    NumPy uses the IEEE Standard for Binary Floating-Point for Arithmetic (IEEE 754).
+    This means that Not a Number is not equivalent to infinity.
+    Also that positive infinity is not equivalent to negative infinity.
+    But infinity is equivalent to positive infinity. Errors result if the second argument
+    is also supplied when x is a scalar input, or if first and second arguments have different shapes.
+
+    Examples
+    --------
+    >>> np.isfinite(1)
+    True
+    >>> np.isfinite(0)
+    True
+    >>> np.isfinite(np.nan)
+    False
+    >>> np.isfinite(np.inf)
+    False
+    >>> np.isfinite(-np.inf)
+    False
+    >>> np.isfinite(np.array([np.log(-1.),1.,np.log(0)]))
+    array([False,  True, False])
+    >>> x = np.array([-np.inf, 0., np.inf])
+    >>> y = np.array([True, True, True], dtype=np.bool)
+    >>> np.isfinite(x, y)
+    array([False,  True, False])
+    >>> y
+    array([False,  True, False])
+    """
+    return _mx_nd_np.isfinite(x, out=out, **kwargs)
+
+
 @set_module('mxnet.numpy')
 def where(condition, x=None, y=None):
     """where(condition, [x, y])

python/mxnet/numpy_dispatch_protocol.py

@@ -175,6 +175,9 @@ def _run_with_array_ufunc_proto(*args, **kwargs):
     'empty_like',
     'nan_to_num',
     'isnan',
+    'isfinite',
+    'isposinf',
+    'isneginf',
     'isinf',
 ]