Changeset 1975

Timestamp:

Dec 7, 2009 6:47:43 PM (11 years ago)

Author:

wehart

Message:

Bug fix. The ProductExpression? was not correctly testing for constant-ness.

Location:

coopr.pyomo/trunk/coopr/pyomo

Files:

• base/expr.py (modified) (2 diffs)
• tests/unit/test_expr.py (modified) (2 diffs)
• tests/unit/varpprint.txt (modified) (3 diffs)

coopr.pyomo/trunk/coopr/pyomo/base/expr.py

@@ -85 +85 @@
     #
     def is_constant(self):
-        if self._args is None:
-            return True
         for arg in self._args:
             if not arg.is_constant():
@@ -201 +199 @@
         self.coef = 1
         Expression.__init__(self,nargs=-1,name='prod')
+
+    def is_constant(self):
+        for arg in self._numerator:
+            if not arg.is_constant():
+                return False
+        for arg in self._denominator:
+            if not arg.is_constant():
+                return False
+        return True
 
     def invert(self):

coopr.pyomo/trunk/coopr/pyomo/tests/unit/test_expr.py

@@ -491 +491 @@
         def c11_rule(model):
             return model.c == model.A+model.B
+        def c15_rule(model):
+            return model.A <= model.A*model.d
+        def c16_rule(model):
+            return model.A*model.d <= model.B
 
         def c12_rule(model):
@@ -533 +537 @@
         model.c10 = Constraint(rule=c10_rule)
         model.c11 = Constraint(rule=c11_rule)
+        model.c15 = Constraint(rule=c15_rule)
+        model.c16 = Constraint(rule=c16_rule)
 
         model.c12 = Constraint(rule=c12_rule)

coopr.pyomo/trunk/coopr/pyomo/tests/unit/varpprint.txt

@@ -40 +40 @@
    o3 :         Size=0  Index= o3_index
 
-14 Constraint Declarations
+16 Constraint Declarations
    c1 :         Size=1 
         None
@@ -71 +71 @@
                 sum( c , -1 *  d ) 
                 Inf
+   c15 :        Size=1 
+        None
+                identity( A )
+                prod( num=( A , d ) ) 
+                Inf
+   c16 :        Size=1 
+        None
+                -Inf
+                prod( num=( A , d ) ) 
+                identity( B )
    c2 :         Size=1 
         None
@@ -120 +130 @@
                 Inf
 
-24 Declarations: a b c d e A B o2 o3_index o3 c1 c2 c3 c4 c5 c6 c7 c8 c9 c10 c11 c12 c13 c14 
+26 Declarations: a b c d e A B o2 o3_index o3 c1 c2 c3 c4 c5 c6 c7 c8 c9 c10 c11 c15 c16 c12 c13 c14