Why does the topic: imu/data in the MAVROS package produce, opposite (negative) values for pitch, yaw and pitch rate and yaw rates?

edit

I am using ROS indigo, Ubuntu 14.04 and the latest MAVROS package. The MAVROS package is used to talk to PX4 and in my code I subscribe to:

/mavros/imu/data

And then I convert the Euler angles and angular rates to degrees and degrees/ second. Then I observed that the pitch angle, yaw angle, the pitch rate and the yaw rate are all opposite of the nominal values. They are negative of what they should be. I have checked the IMU orientation/ installation on the aircraft, and it is correct.

However, when I connect the PX4 to Q-GCS, I can see that all the values displayed in the ground station are correct.

Then why are the MAVROS values wrong? Is it not fetching this data from MAVLINK messages, which is produced by PX4?