fix #234 : implemented support for np.__array_ufunc__

Author: alixdamman

doc/source/changes/version_0_30.rst.inc

@@ -215,6 +215,8 @@ Miscellaneous improvements
   the overall performance improvement is negligible over most of the real-world models using larray that we tested these
   changes on.
 
+* made it possible to pass LArray objects to Numpy ufuncs directly (e.g. np.sqrt(ndtest(3)), closes :issue:`234`).
+
 
 Fixes
 ^^^^^

larray/core/array.py

@@ -57,6 +57,7 @@
 from larray.core.constants import nan
 from larray.core.metadata import Metadata
 from larray.core.expr import ExprNode
+from larray.core.ufuncs import SupportsNumpyUfuncs
 from larray.core.group import (Group, IGroup, LGroup, remove_nested_groups, _to_key, _to_keys,
                                _translate_sheet_name, _translate_group_key_hdf)
 from larray.core.axis import Axis, AxisReference, AxisCollection, X, _make_axis
@@ -700,7 +701,7 @@ def _handle_meta(meta, title):
     return Metadata(meta)
 
 
-class LArray(ABCLArray):
+class LArray(ABCLArray, SupportsNumpyUfuncs):
     r"""
     A LArray object represents a multidimensional, homogeneous array of fixed-size items with labeled axes.