[ros-users] 2d numpy arr msgs?

[Stuart Glaser]

Hi,

I'd suggest the Float64MultiArray message (in std_msgs).  I don't know
of any conversion function that exists for Python yet.

-Stu

On Mon, Jun 14, 2010 at 3:52 PM, James Bowman <jamesb at willowgarage.com> wrote:
> You can turn the numpy array into a single-channel CV image, then use
> cv_bridge to turn it into a message:
>
> msg = CvBridge().cv_to_imgmsg(cv.fromarray(a))
>
> and:
>
> a = numpy.fromarray(CvBridge().imgmsg_to_cv(msg))
>
>
> On Mon, Jun 14, 2010 at 3:27 PM, Ken Conley <kwc at willowgarage.com> wrote:
>>
>> The ROS msg IDL only supports 1D arrays. The reshape approach is the
>> correct approach to ensure compatibility in multiple languages.
>>
>>  - Ken
>>
>> On Mon, Jun 14, 2010 at 3:23 PM, Floris van Breugel <florisvb at gmail.com>
>> wrote:
>>>
>>> Hi folks,
>>>
>>> Is there a way to publish 2D numpy arrays as messages (using python)? I
>>> went through the numpy tutorial for rospy but it seems to only work for 1D
>>> arrays. I suppose one could reshape the 2D array to be 1D, and pass the
>>> shape as another message, and then reconstruct it on the other side, but
>>> maybe there's a more efficient way to do it? Or that functionality could be
>>> added to numpy_msg.py?
>>> http://www.ros.org/wiki/rospy_tutorials/Tutorials/numpy
>>>
>>> Thanks!
>>>
>>> - Floris
>>>
>>>
>>>
>>> --
>>> Floris van Breugel
>>> Caltech Graduate Student
>>> Control and Dynamical Systems
>>> (925) 963 8280
>>>
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>>
>>
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>
>
>
> --
> J.
>
>
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-- 
Stuart Glaser
sglaser -at- willowgarage -dot- com
www.willowgarage.com