Fix shape bug when raising multivariate enclosures to a power.

This fixes #10

Also bump version number in preparation for updating the pip package.

autobound/__init__.py

@@ -12,4 +12,4 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-__version__ = "0.1.2"
+__version__ = "0.1.3"

autobound/enclosure_arithmetic.py

@@ -328,7 +328,8 @@ def power(self, a: TaylorEnclosureLike, p: float) -> TaylorEnclosure:
       term_power_coefficient = functools.partial(
           _elementwise_term_power_coefficient, x_ndim=x_ndim,
           np_like=self.np_like)
-      multiplicative_identity = self.np_like.ones_like(self.trust_region[0])
+      a0 = a[0][0] if isinstance(a[0], tuple) else a[0]
+      multiplicative_identity = self.np_like.ones_like(a0)
       result = polynomials.integer_power(  # pytype: disable=wrong-arg-types
           a,
           p,

autobound/enclosure_arithmetic_test.py

@@ -225,6 +225,27 @@ def test_pairwise_batched_multiply(self, u, v, p, q, expected):
           0,
           (np.ones((3,)),)
       ),
+      (
+          100,
+          (np.zeros((2,)), np.ones((2,))),
+          (np.ones((3,)), np.ones((3, 2))),
+          0,
+          (np.ones((3,)),)
+      ),
+      (
+          100,
+          (np.zeros((2,)), np.ones((2,))),
+          (np.ones((3,)), np.ones((3, 2))),
+          1,
+          (np.ones((3,)), np.ones((3, 2))),
+      ),
+      (
+          100,
+          (np.zeros((2,)), np.ones((2,))),
+          (np.ones((3,)), np.ones((3, 2))),
+          2,
+          (np.ones((3,)), 2*np.ones((3, 2)), np.ones((3, 2, 2))),
+      ),
   )
   def test_power(self, max_degree, trust_region, enclosure, p, expected):
     for np_like in self.backends: