Merge pull request #2 from ScottMacLachlan/scottmac/trig_identity

Using trig identity for sinc2d

code/mymath.py

@@ -8,7 +8,7 @@ def sinc2d(x,y):
     elif y==0:
         return m.sin(x)/x
     else:
-        return (m.sin(x)/x)*(m.sin(y)/y)
+        return (m.cos(x-y) - m.cos(x+y))/(2*x*y)
 
 def addone(x):
     return x+1