v1.2.5 (#42)

* incremented version

* Update test_subgraph.py

* Update _subgraph.py

* Update test_subgraph.py

* Update README.rst

* Update requirements-dev.txt

README.rst

@@ -96,7 +96,7 @@ Create the boolean objective function to minimize
     # create the variables
     x = {i: boolean_var('x(%d)' % i) for i in range(N)}
 
-    # minimize \sum_{i=0}^{N-1} (1-2x_{i}) x_{i+1}
+    # minimize \sum_{i=0}^{N-2} (1-2x_{i}) x_{i+1}
     model = 0
     for i in range(N-1):
         model += (1 - 2 * x[i]) * x[i+1]

qubovert/_version.py

@@ -20,7 +20,7 @@
 )
 
 
-__version__ = "1.2.4"
+__version__ = "1.2.5"
 __author__ = "Joseph T. Iosue"
 __authoremail__ = "[email protected]"
 __license__ = "Apache Software License 2.0"

qubovert/utils/_subgraph.py

@@ -90,6 +90,8 @@ def subgraph(G, nodes, connections=None):
         value += D.get(key, 0)
         if value:
             D[key] = value
+        else:
+            D.pop(key, 0)
 
     return D
 
@@ -134,5 +136,7 @@ def subvalue(values, G):
         value += D.get(key, 0)
         if value:
             D[key] = value
+        else:
+            D.pop(key, 0)
 
     return D

tests/utils/test_subgraph.py

@@ -44,6 +44,10 @@ def test_subgraph():
     with assert_raises(ValueError):
         subgraph({0: 1, (0, 1): 1}, {})
 
+    # from Issue #38 in GitHub
+    G = {(2,): 1, (2, 3): -1}
+    assert subgraph(G, {2}, {3: 1}) == {}
+
 
 def test_subvalue():
 
@@ -65,3 +69,7 @@ def test_subvalue():
     # edge case
     assert subvalue({}, G) == G
     assert subvalue({0: 0, 1: 0, 2: 0}, G) == {(): 2}
+
+    # from Issue #38 in GitHub
+    G = {(2,): 1, (2, 3): -1}
+    assert subvalue({3: 1}, G) == {}