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Messages not getting subscribed using message_filters [closed]

asked 2012-02-12 04:07:41 -0600

alfa_80 gravatar image

updated 2012-02-12 06:35:26 -0600

I've been trying quite a long time to get the message_filters running, however, until now, it's still problematic. I am specifically interested in trying the code snippet in 5.2 (although I've tried a lot of the variants of them, including ones from policy-based), but I still couldn't be able to succeed.

My goal is actually to synchronize some messages coming in, to be called back in a single callback function. I think the one from section 5.2 would suffice for this purpose.

Nevertheless, they return neither error nor warnings, but when I check the output via rxgraph(if they are ever got subscribed), nothing appears there.

How should I debug it.

Thanks in advance.


Not rxgraph, instead rxconsole.

I've tried to subscribe using standard subscribers and I observed that the timestamp for the both requested messages are the same like below:

From poseLD
Time: 1329078573.249072112
[ INFO] [1329078573.249784103]: 
From poseLS
Time: 1329078573.249072112
From poseLD
Time: 1329078573.582401742
[ INFO] [1329078573.582850256]: 
From poseLS
Time: 1329078573.582401742
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Closed for the following reason question is not relevant or outdated by tfoote
close date 2013-09-09 14:51:50

1 Answer

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answered 2012-02-12 05:11:32 -0600

What do you mean that nothing appears in rxgraph?

One thing to try would be to try using standard subscribers for your topics and make sure you're getting messages coming in. Once you verify that you are indeed getting messages, check to make sure that there are messages on each topic with identical timestamps. If there aren't, you should either change something wherever your messages are being produced to ensure they're actually synchronized, or switch to an ApproximateTime policy.

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rxconsole sorry, not rxgraph.
alfa_80 gravatar image alfa_80  ( 2012-02-12 05:20:03 -0600 )edit
If you were to look in rxgraph, does it show that the topics are connected correctly?
Dan Lazewatsky gravatar image Dan Lazewatsky  ( 2012-02-12 05:38:33 -0600 )edit
The publishers were publishing messages as they were supposed, but the subscribers are not subscribing in a callback.
alfa_80 gravatar image alfa_80  ( 2012-02-12 05:46:23 -0600 )edit

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Asked: 2012-02-12 04:07:41 -0600

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Last updated: Feb 12 '12