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Message data type and accessing message fields

asked 2011-11-05 08:41:19 -0500

Paul0nc
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I'm trying to use the /body_msgs/skeletons message (from the MIT hand_interaction demo). I'm trying to write a subscriber callback function. How can I tell the type of the message (for the callback prototype declaration)?

Also, this message has many fields (x,y,z coordinates of various joints). How would I access any individual coordinate such as left_hip/y ?

Thanks, Paul

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answered 2011-11-05 10:42:38 -0500

kwc
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I recommend following the relevant ROS tutorials on writing publishers and subscribers for your relevant language:

http://www.ros.org/wiki/ROS/Tutorials

e.g. "Writing a Simple Publisher and Subscriber (C++)"

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Thanks kwc. I have worked through these tutorials. I'm still not clear on how to access fields of a message or what is the type of a message composed of many variables. The tutorials use standard types having only a single field. Apologies if this is basic.

Paul0nc ( 2011-11-05 13:49:40 -0500 )edit

Multiple fields is no different from a single field: you just access the field by its name. i.e. if you type "msg.data", you are accessing the 'data' field.

kwc ( 2011-11-05 15:22:28 -0500 )edit

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Asked: 2011-11-05 08:41:19 -0500

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Last updated: Nov 05 '11

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Message data type and accessing message fields