BUG: fix NumPy 1.7 cast-to-bool failure and buglet

Author: wesm

doc/source/timeseries.rst

@@ -297,7 +297,7 @@ We could have done the same thing with ``DateOffset``:
 
 .. ipython:: python
 
-   from pandas.core.datetools import *
+   from pandas.tseries.offsets import *
    d + DateOffset(months=4, days=5)
 
 The key features of a ``DateOffset`` object are:

pandas/core/frame.py

@@ -4226,9 +4226,9 @@ def _reduce(self, op, axis=0, skipna=True, numeric_only=None,
         if result.dtype == np.object_:
             try:
                 if filter_type is None or filter_type == 'numeric':
-                    result = result.astype('f8')
-                elif filter_type == 'bool':
-                    result = result.astype('b')
+                    result = result.astype(np.float64)
+                elif filter_type == 'bool' and notnull(result).all():
+                    result = result.astype(np.bool_)
                 else:
                     raise ValueError('Invalid dtype %s ' % str(filter_type))
 

pandas/core/index.py

@@ -405,7 +405,7 @@ def asof(self, label):
     def asof_locs(self, where, mask):
         """
         where : array of timestamps
-        mask : array of booleans where data is NA
+        mask : array of booleans where data is not NA
 
         """
         locs = self.values[mask].searchsorted(where.values, side='right')