Added ProductDomain to api doc

Author: ihincks

doc/source/apiref/domains.rst

@@ -32,6 +32,16 @@ Class Reference
 .. autoclass:: Domain
     :members:
 
+
+:class:`ProductDomain` - Cartesian product of multiple domains
+--------------------------------------------------------------
+
+Class Reference 
+~~~~~~~~~~~~~~~
+.. autoclass:: ProductDomain
+    :members:
+
+    
 :class:`RealDomain` - (A subset of) Real Numbers
 ------------------------------------------------
 
@@ -58,4 +68,4 @@ This domain is used by :class:`MultinomialModel`.
 Class Reference 
 ~~~~~~~~~~~~~~~
 .. autoclass:: MultinomialDomain
-    :members:
+    :members:

src/qinfer/domains.py

@@ -152,8 +152,8 @@ class ProductDomain(Domain):
     """
     A domain made from the cartesian product of other domains.
 
-    :param Domain domains: ``Domain`` objects as separate arguments, 
-        or as a singe list of ``Domain``s.
+    :param Domain domains: ``Domain`` instances as separate arguments, 
+        or as a singe list of ``Domain`` instances.
     """
     def __init__(self, *domains):
 
@@ -268,7 +268,7 @@ def from_regular_arrays(self, arrays):
         corresponding to the factor domains into a single array 
         with the dtype of the ``ProductDomain``.
 
-        :param list array: A list of ``np.ndarray``s
+        :param list array: A list with each element of type ``np.ndarray``
 
         :rtype: `np.ndarray`
         """