TImeseries construction of Rosbag messages in Matlab fails!

Hey all,

Reading messages from rosbags in matlab works fine. However when doing a timeseries of that data (ts=timeseries(msgs);) i get an error saying that there is no property for that message!

Here are the commands:

bag = rosbag('./bagfiles/b-it-bots_2016_04_14_16-39.bag')
bag1 = select(bag, 'Topic','/joint_states')
msgs = readMessages(bag1)
ts = timeseries(msgs, 'Position')

The last command throws the following error:

Error using timeseries/init (line 88)
A specified property has no corresponding value.

Error in timeseries (line 324)
                this = init(this,vara

Anyone has any idea what is causing this?

Cheers

[Sebastian Castro]

If you do

>> rostopic info joint_states

and look at the message type (which normally should be sensor_msgs/JointState), you can then do

>> rosmsg info sensor_msgs/JointState

This should tell you the structure of the data and what is available to pick from those messages.

If for some reason your /joint_states topic is using a different message type, that may be why the timeseries is unable to find a Position field?

- Sebastian