Source Code for Module rospy.numpy_msg

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34   
35  """ 
36  Support for using numpy with rospy messages. 
37   
38  For tutorials, see U{http://www.ros.org/wiki/rospy_tutorials/Tutorials/numpy} 
39   
40  Listener example:: 
41      from rospy.numpy_msg import numpy_msg 
42   
43      rospy.init_node('mynode') 
44      rospy.Subscriber("mytopic", numpy_msg(TopicType) 
45   
46  Publisher example:: 
47   
48      from rospy.numpy_msg import numpy_msg 
49      import numpy 
50       
51      pub = rospy.Publisher('mytopic', numpy_msg(TopicType)) 
52      rospy.init_node('mynode') 
53      a = numpy.array([1.0, 2.1, 3.2, 4.3, 5.4, 6.5], dtype=numpy.float32) 
54      pub.publish(a) 
55  """ 
56   
57  import numpy 
58   
59  # TODO: we will need to generate a new type structure with 
60  # little-endian specified and then pass that type structure into the 
61  # *_numpy calls. 
62   
63 -def _serialize_numpy(self, buff): 
64      """ 
65      wrapper for factory-generated class that passes numpy module into serialize 
66      """ 
67      # pass in numpy module reference to prevent import in auto-generated code 
68      return self.serialize_numpy(buff, numpy) 
69   
70 -def _deserialize_numpy(self, str): 
71      """ 
72      wrapper for factory-generated class that passes numpy module into deserialize     
73      """ 
74      # pass in numpy module reference to prevent import in auto-generated code 
75      return self.deserialize_numpy(str, numpy) 
76       
77  ## Use this function to generate message instances using numpy array 
78  ## types for numerical arrays.  
79  ## @msg_type Message class: call this functioning on the message type that you pass 
80  ## into a Publisher or Subscriber call.  
81  ## @returns Message class 
82 -def numpy_msg(msg_type): 
83      classdict = { '__slots__': msg_type.__slots__, '_slot_types': msg_type._slot_types, 
84                    '_md5sum': msg_type._md5sum, '_type': msg_type._type, 
85                    '_has_header': msg_type._has_header, '_full_text': msg_type._full_text, 
86                    'serialize': _serialize_numpy, 'deserialize': _deserialize_numpy, 
87                    'serialize_numpy': msg_type.serialize_numpy, 
88                    'deserialize_numpy': msg_type.deserialize_numpy 
89                    } 
90   
91      # create the numpy message type 
92      msg_type_name = "Numpy_%s"%msg_type._type.replace('/', '__') 
93      return type(msg_type_name,(msg_type,),classdict) 
94