ROS Answers: Open Source Q&A Forum - RSS feedhttps://answers.ros.org/questions/Open source question and answer forum written in Python and DjangoenROS Answers is licensed under Creative Commons Attribution 3.0Fri, 23 Mar 2012 18:46:32 -0500problem in geometry_msgs::Posehttps://answers.ros.org/question/30340/problem-in-geometry_msgspose/what is x, y, z and w in Quaternion oriention?
specially what is w?Fri, 23 Mar 2012 04:15:26 -0500https://answers.ros.org/question/30340/problem-in-geometry_msgspose/Answer by Stefan Kohlbrecher for <p>what is x, y, z and w in Quaternion oriention?
specially what is w?</p>
https://answers.ros.org/question/30340/problem-in-geometry_msgspose/?answer=30343#post-id-30343Have a look at [REP103](http://www.ros.org/reps/rep-0103.html) on Standard Units of Measure and Coordinate Conventions. If you're not familiar with quaternions it also helps to have a look at pages like [this Wikipedia page on Quaternions and spatial rotation](http://en.wikipedia.org/wiki/Quaternions_and_spatial_rotation).Fri, 23 Mar 2012 04:25:09 -0500https://answers.ros.org/question/30340/problem-in-geometry_msgspose/?answer=30343#post-id-30343Comment by Tully for <p>Have a look at <a href="http://www.ros.org/reps/rep-0103.html">REP103</a> on Standard Units of Measure and Coordinate Conventions. If you're not familiar with quaternions it also helps to have a look at pages like <a href="http://en.wikipedia.org/wiki/Quaternions_and_spatial_rotation">this Wikipedia page on Quaternions and spatial rotation</a>.</p>
https://answers.ros.org/question/30340/problem-in-geometry_msgspose/?comment=30382#post-id-30382Also for information about any message you can use the rosmsg command with the --raw option to see the comments. Or browse the online docs for the message http://ros.org/doc/electric/api/geometry_msgs/html/msg/Pose.html Fri, 23 Mar 2012 18:46:32 -0500https://answers.ros.org/question/30340/problem-in-geometry_msgspose/?comment=30382#post-id-30382Answer by michikarg for <p>what is x, y, z and w in Quaternion oriention?
specially what is w?</p>
https://answers.ros.org/question/30340/problem-in-geometry_msgspose/?answer=30344#post-id-30344Hi,
For representing orientation in ROS, quaternions are used. They do not represent a human-readable format like e.g. euler angles (more information about quaternions here: http://en.wikipedia.org/wiki/Quaternion ).
To easily convert between euler angles and quaternions, the tf-ROS package offers a set of functions like "createQuaternionFromYaw" or similar...
Have a look at <tf/transform_datatypes.h> for more information. Fri, 23 Mar 2012 04:25:40 -0500https://answers.ros.org/question/30340/problem-in-geometry_msgspose/?answer=30344#post-id-30344