Source Code for Package mglutil.math

 1  import Numeric 
 2  N=Numeric 
 3  import types 
 4   
 5 -def crossProduct (A, B, normal=True): 
 6      """     Return cross product of two vectors A and B 
 7  normal: return normalized vector 
 8  """ 
 9      res=[ A[1]*B[2] - A[2]*B[1], 
10            A[2]*B[0] - A[0]*B[2], 
11            A[0]*B[1] - A[1]*B[0] ] 
12      if normal: 
13          return norm(res) 
14      else: 
15          return res 
16   
17 -def norm (A): 
18      """     Return normalized vector A. 
19  """ 
20      if type(A) == types.ListType: 
21          A=Numeric.array(A,'f') 
22          res= A/Numeric.sqrt(Numeric.dot(A,A)) 
23          return res.tolist()     
24      elif type(A)==Numeric.ArrayType:     
25          return A/Numeric.sqrt(Numeric.dot(A,A))     
26      else: 
27          print "Need a list or Numeric array" 
28          return None 
29   
30 -def getCenter(coords): 
31      """ get center of all the coords """ 
32      coords=N.array(coords, 'f')     
33      return (N.sum(coords)/len(coords)).tolist() 
34