Hi Cedric,<div><br></div><div>I don't know if what you say applies here. If I understood you well when you mention 'testing software', that would be achieved using 'rosbag play'. If you are using 'rostopic echo' you'll just get a bunch of data printed on screen (or to a text file).</div>
<div><br></div><div>Miguel.<br><br><div class="gmail_quote">2010/6/9 Cedric Pradalier <span dir="ltr"><<a href="mailto:cedric.pradalier@mavt.ethz.ch">cedric.pradalier@mavt.ethz.ch</a>></span><br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
<div class="im">On 06/09/2010 04:31 PM, Jeremy Leibs wrote:<br>
> Agreed. I was also surprised to find it didn't print bag time. I<br>
> created ticket: <a href="https://code.ros.org/trac/ros/ticket/2780" target="_blank">https://code.ros.org/trac/ros/ticket/2780</a> to track<br>
> this issue.<br>
><br>
<br>
</div>I actually implemented a playback functionality for another middleware<br>
some time ago, and I had put that as an option.<br>
In some context, one would want to have the time at which the data was<br>
recorded (for plotting for instance).<br>
On the other hand, if you test some software, then it's better to put<br>
the writing time, to have a feeling of real-time.<br>
<br>
Then I also had an option for time scaling (fast-forward or<br>
slow-motion). Then again, the choice of old time-stamp, write time-stamp<br>
becomes tricky, especially if you introduce a pause mechanism in the<br>
playback.<br>
<br>
Even without the special features above, I think both type of timestamp<br>
are sometimes useful, and only a command-line option can select between<br>
them.<br>
<br>
HTH<br>
<div><div></div><div class="h5"><br>
> On Wed, Jun 9, 2010 at 2:14 AM, Miguel Prada<<a href="mailto:miguel.register@gmail.com">miguel.register@gmail.com</a>> wrote:<br>
><br>
>> Hi Jeremy,<br>
>><br>
>> Thanks for the tip. That's exactly what I've been doing after writing to the list and it works great.<br>
>><br>
>> However, shouldn't rostopic output the bagfile's timestamps when echoing from a bagfile? I find it much more reasonable than having to programatically read the data using python to achieve this result. Am I missing some important reason for rostopic echo to behave this way?<br>
>><br>
>> Miguel.<br>
>><br>
>> El 09/06/2010, a las 10:33, Jeremy Leibs escribió:<br>
>><br>
>><br>
>>> Assuming you are still using boxturtle, rosrecord has a rosrecord.py<br>
>>> programmatic API<br>
>>><br>
>>> Take a look at:<br>
>>><br>
>>> <a href="http://www.ros.org/wiki/rosrecord#rosrecord.py" target="_blank">http://www.ros.org/wiki/rosrecord#rosrecord.py</a><br>
>>><br>
>>> It should be fairly straight forward to write a small program which<br>
>>> opens the bag and prints exactly what you want.<br>
>>><br>
>>> On Wed, Jun 9, 2010 at 1:29 AM, Miguel Prada<<a href="mailto:miguel.register@gmail.com">miguel.register@gmail.com</a>> wrote:<br>
>>><br>
>>>> Hi,<br>
>>>><br>
>>>> I want to manipulate some data from a bag file with a spreadsheet. I'm exporting from the bag to CSV using 'rostopic echo -p -b BAGFILE TOPIC>> file.csv' but I just realised that the time field you get from doing that is the time corresponding to when rostopic is run, not the time stored in the bag file. That means that if I use this method to output messages in one topic and then repeat for another topic (e.g. controller commands and robot positions) the time fields on both CSV files are of no use at all to merge the data in those two files.<br>
>>>><br>
>>>> I tried using 'rostopic echo -p -b BAGFILE -a>> file.csv' to print all topics at once, but the output is quite messed up and doesn't clearly state which data corresponds to which topic.<br>
>>>><br>
>>>> Does anyone have any suggestion on how should I proceed with this?<br>
>>>><br>
>>>> Miguel.<br>
>>>><br>
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<br>
</div></div><font color="#888888">--<br>
Dr. Cedric Pradalier<br>
<a href="http://www.asl.ethz.ch/people/cedricp" target="_blank">http://www.asl.ethz.ch/people/cedricp</a><br>
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