Changeset 1916

Timestamp:

Oct 14, 2005, 9:46:38 AM (19 years ago)

Author:

ole

Message:

Implemented operator overloading for (pow) in class Quantity and tested.
Wrote create_quantity_from_expression and test.

Location:

inundation/pyvolution

Files:

• domain.py (modified) (3 diffs)
• quantity.py (modified) (3 diffs)
• test_domain.py (modified) (1 diff)
• test_quantity.py (modified) (2 diffs)

inundation/pyvolution/domain.py

@@ -187 +187 @@
         """
 
+        #FIXME (Ole): Allow new quantities
+        
         #from quantity import Quantity, Conserved_quantity
 
@@ -219 +221 @@
 
         return self.quantities[name].get_values( location, indices = indices)
+
+
+
 
 
@@ -724 +729 @@
 
 
+
+def create_quantity_from_expression(domain, expression):
+    """Create new quantity from other quantities using arbitrary expression
+
+    Combine existing quantities in domain using expression and return
+    result as a new quantity.
+
+    Note, the new quantity could e.g. be used in set_quantity
+
+    Valid expressions are limited to operators defined in class Quantity
+
+    Example:
+      
+    
+    """
+
+    #Replace quantity names with actual quantities
+    quantities = domain.quantities
+    for quantity_name in quantities.keys():
+        expression = expression.replace(quantity_name,
+                                        'quantities["%s"]' %quantity_name)
+
+    #Evaluate and return
+    return eval(expression)   
+    
+
+
 ##############################################
 #Initialise module

inundation/pyvolution/quantity.py

@@ -72 +72 @@
 
     def __add__(self, other):
-        """Add to self anything that could populate a quantity:
+        """Add to self anything that could populate a quantity
+        
         E.g other can be a constant, an array, a function, another quantity
         (except for a filename or points, attributes (for now))
@@ -95 +96 @@
 
     def __mul__(self, other):
-        """Multiply self with anything that could populate a quantity:
+        """Multiply self with anything that could populate a quantity
+        
         E.g other can be a constant, an array, a function, another quantity
         (except for a filename or points, attributes (for now))
@@ -118 +120 @@
         """
         return self * other
+
+    def __pow__(self, other):
+        """Raise quantity to (numerical) power
+
+        As with __mul__ vertex values are processed entry by entry
+        while centroid and edge values are re-interpolated.
+
+        Example using __pow__:
+          Q = (Q1**2 + Q2**2)**0.5
+
+        """
+
+        result = Quantity(self.domain)
+        result.set_values(self.vertex_values**other)
+        return result
+        
     
 

inundation/pyvolution/test_domain.py

@@ -134 +134 @@
         q = domain.get_conserved_quantities(3, edge=2)
         assert allclose(q, [-1.5, -1.5, 0.])
+
+
+
+    def test_create_quantity_from_expression(self):
+        """Quantity created from other quantities using arbitrary expression
+        
+        """
+
+
+        a = [0.0, 0.0]
+        b = [0.0, 2.0]
+        c = [2.0,0.0]
+        d = [0.0, 4.0]
+        e = [2.0, 2.0]
+        f = [4.0,0.0]
+
+        points = [a, b, c, d, e, f]
+        #bac, bce, ecf, dbe, daf, dae
+        vertices = [ [1,0,2], [1,2,4], [4,2,5], [3,1,4]]
+
+        domain = Domain(points, vertices, boundary=None,
+                        conserved_quantities =\
+                        ['stage', 'xmomentum', 'ymomentum'],
+                        other_quantities = ['elevation', 'friction'])
+
+
+        domain.set_quantity('elevation', -1)
+
+        
+        domain.set_quantity('stage', [[1,2,3], [5,5,5],
+                                      [0,0,9], [-6, 3, 3]])
+
+        domain.set_quantity('xmomentum', [[1,2,3], [5,5,5],
+                                          [0,0,9], [-6, 3, 3]])
+
+        domain.set_quantity('ymomentum', [[3,3,3], [4,2,1],
+                                          [2,4,-1], [1, 0, 1]])        
+
+        domain.check_integrity()
+
+
+
+        expression = 'stage - elevation'
+        Q = create_quantity_from_expression(domain, expression)
+
+        assert allclose(Q.vertex_values, [[2,3,4], [6,6,6],
+                                      [1,1,10], [-5, 4, 4]])
+
+        expression = '(xmomentum*xmomentum + ymomentum*ymomentum)**0.5'
+        Q = create_quantity_from_expression(domain, expression)
+
+        X = domain.quantities['xmomentum'].vertex_values
+        Y = domain.quantities['ymomentum'].vertex_values        
+
+        assert allclose(Q.vertex_values, (X**2 + Y**2)**0.5)
+                                      
+
+
+
 
 

inundation/pyvolution/test_quantity.py

@@ -522 +522 @@
                         3*quantity3.vertex_values + 5)                                        
         
-    
+
+        #Powers
+        Q = quantity1**2
+        assert allclose(Q.vertex_values, quantity1.vertex_values**2)
+
+        Q = quantity1**2 +quantity2**2 
+        assert allclose(Q.vertex_values,
+                        quantity1.vertex_values**2 + \
+                        quantity2.vertex_values**2)
+
+        Q = (quantity1**2 +quantity2**2)**0.5 
+        assert allclose(Q.vertex_values,
+                        (quantity1.vertex_values**2 + \
+                        quantity2.vertex_values**2)**0.5)
+        
+
+
+        
+        
+        
 
     def test_gradient(self):
@@ -1208 +1227 @@
 
 
+
 #-------------------------------------------------------------
 if __name__ == "__main__":