Document NaN support in interfaces and NaN usage in CLI #4210
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Signed-off-by: Ryan Friedman <[email protected]>
| @@ -183,6 +183,7 @@ Field default value | |||
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| Default values can be set to any field in the message type. | |||
| Currently default values are not supported for string arrays and complex types (i.e. types not present in the built-in-types table above; that applies to all nested messages). | |||
| Special floating point values such as ``NaN``, ``+infinity``, and ``-infinity`` are not yet supported as default values. | |||
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just a comment, this does not block the PR.
instead of adding the limitation here temporary, can we update the doc after ros2/rosidl#789?
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Yep, I'm not in a rush to fix the docs, and am happy to revise if we can get a quick review and merge on the ROSIDL PR.
source/Tutorials/Beginner-CLI-Tools/Understanding-ROS2-Topics/Understanding-ROS2-Topics.rst
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Co-authored-by: Tomoya Fujita <[email protected]> Signed-off-by: Ryan <[email protected]>
| Certain messages use ``NaN`` as a significant value. | ||
| For example, with a ``sensor_msgs/msg/BatteryState``, the temperature field may not be measured. | ||
| If so, it should be set to ``NaN``. | ||
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| .. code-block:: console | ||
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| ros2 topic pub /battery sensor_msgs/msg/BatteryState '{voltage: 12.4, temperature: .nan}' | ||
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I don't think that this is appropriate for the Beginner documentation. The point of the beginner docs is to show one way to do it, not to document all of the nuances and alternate ways to do it. Instead, I'll suggest putting this in another tutorial or how-to guide that talks about ros2 topic pub.
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Sounds like I could write a new how-to guide on for Advanced usage of ros2 topic. Seems like a good spot to also talk about hidden topics since the docs don't cover those
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Sounds like I could write a new how-to guide on for
Advanced usage of ros2 topic. Seems like a good spot to also talk abouthiddentopics since the docs don't cover those
That sounds very reasonable to me. That could also possibly go into Tutorials/Advanced .
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@Ryanf55 Would you like to remove this portion from this PR, so we can put the changes to About-Interfaces in? Then when you have time you could write the advanced tutorial.
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yea, I'm swamped now. in the mean time, can we get some capable maintainers to review the two proposed PR's and provide input to the blocks with IDL and JSON not supporting NaN?
Purpose
Document what is currently supported by ROS when using NaN/infinity values for floating points in messaging.
Why
sensor_msgs/msg/BatteryStatetells users to useNaN, but there's not info in the docs on working with NaN's. This documents what currently exists. I plan to improve support for NaN's across the ROS ecosystem because they are heavily used in the aerial messages of REP-147 and in MAVLink.Ticket
Closes #4135