Hi, I think this kind of question is best asked on answers.ros.org. Also make sure you have a look at the support page here: http://ros.org/wiki/Support Lorenz On Mon, Dec 10, 2012 at 4:53 PM, Francesco Corucci wrote: > Hi everyone, > > I've just started working with ros, this is my first post here :-) > > I'd like to ask a question: I have a publisher that publishes a kinect > stream at a certain rate. > > Until now I've always needed to process every snapshot, so I just subscribed > to the topic and process each message in my callback. > > I was thinking that sometimes it could be useful for a client to get single > messages, sporadically, from a periodic publisher. Is there an easy way to > do that? > > I could skip messages in my callback until I want to grab one, but I'd like > to avoid the overhead of the calls I don't need. > > I guess I could play with subscribe/ubsubscribe on demand, but I imagine it > would be very slow. > > The better way that I was able to think is to modify the publisher, adding a > service that, when called, returns just the last message. > This way it could be possible to have a periodic publisher that could also > be used as a "sporadic" publisher. Is this the best solution, or there's > something simpler, that doesn't need to modify the publisher? > > To simplify, I want to use the same publisher as sporadic for some clients, > as periodic for some others. > > Thank you :-) > > > -- Francesco > > _______________________________________________ > ros-users mailing list > ros-users@code.ros.org > https://code.ros.org/mailman/listinfo/ros-users > -- Lorenz Mösenlechner | moesenle@in.tum.de Technische Universität München | Karlstraße 45 80335 München | Germany http://ias.cs.tum.edu/ | Tel: +49 (89) 289-26910