Merge from the doc wiki

1 files changed, 59 insertions, 35 deletions

diff --git a/numpy/lib/ufunclike.py b/numpy/lib/ufunclike.py
index 8ea7c6662..5dbc3f225 100644
--- a/numpy/lib/ufunclike.py
+++ b/numpy/lib/ufunclike.py
@@ -27,7 +27,7 @@ def fix(x, y=None):
 
     See Also
     --------
-    floor : Round downwards
+    trunc, floor, ceil
     around : Round to given number of decimals
 
     Examples
@@ -50,48 +50,40 @@ def fix(x, y=None):
 
 def isposinf(x, y=None):
     """
-    Shows which elements of the input are positive infinity.
-
-    Returns a numpy array resulting from an element-wise test for positive
-    infinity.
+    Test element-wise for positive infinity, return result as bool array.
 
     Parameters
     ----------
     x : array_like
-      The input array.
-    y : array_like
-      A boolean array with the same shape as `x` to store the result.
+        The input array.
+    y : array_like, optional
+        A boolean array with the same shape as `x` to store the result.
 
     Returns
     -------
     y : ndarray
-      A numpy boolean array with the same dimensions as the input.
-      If second argument is not supplied then a numpy boolean array is returned
-      with values True where the corresponding element of the input is positive
-      infinity and values False where the element of the input is not positive
-      infinity.
+        A boolean array with the same dimensions as the input.
+        If second argument is not supplied then a boolean array is returned
+        with values True where the corresponding element of the input is
+        positive infinity and values False where the element of the input is
+        not positive infinity.
 
-      If second argument is supplied then an numpy integer array is returned
-      with values 1 where the corresponding element of the input is positive
-      positive infinity.
+        If a second argument is supplied the result is stored there. If the
+        type of that array is a numeric type the result is represented as zeros
+        and ones, if the type is boolean then as False and True.
+        The return value `y` is then a reference to that array.
 
     See Also
     --------
-    isinf : Shows which elements are negative or positive infinity.
-    isneginf : Shows which elements are negative infinity.
-    isnan : Shows which elements are Not a Number (NaN).
-    isfinite: Shows which elements are not: Not a number, positive and
-             negative infinity
+    isinf, isneginf, isfinite, isnan
 
     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.
-    Also that positive infinity is not equivalent to negative infinity. But
-    infinity is equivalent to positive infinity.
+    (IEEE 754).
 
-    Errors result if second argument is also supplied with scalar input or
-    if first and second arguments have different shapes.
+    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
     --------
@@ -103,9 +95,10 @@ def isposinf(x, y=None):
     array(False, dtype=bool)
     >>> np.isposinf([-np.inf, 0., np.inf])
     array([False, False,  True], dtype=bool)
-    >>> x=np.array([-np.inf, 0., np.inf])
-    >>> y=np.array([2,2,2])
-    >>> np.isposinf(x,y)
+
+    >>> x = np.array([-np.inf, 0., np.inf])
+    >>> y = np.array([2, 2, 2])
+    >>> np.isposinf(x, y)
     array([1, 0, 0])
     >>> y
     array([1, 0, 0])
@@ -119,29 +112,60 @@ def isposinf(x, y=None):
 
 def isneginf(x, y=None):
     """
-    Return True where x is -infinity, and False otherwise.
+    Test element-wise for negative infinity, return result as bool array.
 
     Parameters
     ----------
     x : array_like
-      The input array.
-    y : array_like
-      A boolean array with the same shape as `x` to store the result.
+        The input array.
+    y : array_like, optional
+        A boolean array with the same shape and type as `x` to store the
+        result.
 
     Returns
     -------
     y : ndarray
-      A boolean array where y[i] = True only if x[i] = -Inf.
+        A boolean array with the same dimensions as the input.
+        If second argument is not supplied then a numpy boolean array is
+        returned with values True where the corresponding element of the
+        input is negative infinity and values False where the element of
+        the input is not negative infinity.
+
+        If a second argument is supplied the result is stored there. If the
+        type of that array is a numeric type the result is represented as
+        zeros and ones, if the type is boolean then as False and True. The
+        return value `y` is then a reference to that array.
 
     See Also
     --------
-    isposinf, isfinite
+    isinf, isposinf, isnan, isfinite
+
+    Notes
+    -----
+    Numpy uses the IEEE Standard for Binary Floating-Point for Arithmetic
+    (IEEE 754).
+
+    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.isneginf(np.NINF)
+    array(True, dtype=bool)
+    >>> np.isneginf(np.inf)
+    array(False, dtype=bool)
+    >>> np.isneginf(np.PINF)
+    array(False, dtype=bool)
     >>> np.isneginf([-np.inf, 0., np.inf])
     array([ True, False, False], dtype=bool)
 
+    >>> x = np.array([-np.inf, 0., np.inf])
+    >>> y = np.array([2, 2, 2])
+    >>> np.isneginf(x, y)
+    array([1, 0, 0])
+    >>> y
+    array([1, 0, 0])
+
     """
     if y is None:
         x = nx.asarray(x)