Error in converting Eigen::Quaternion to Eigen::AngleAxis in cost function

[aeoleader]

Hi all,

How to convert an Eigen::Quaternion object to AngleAxis representation? I have tried the following code with no luck.

Eigen::Quaternion<T> quat = Eigen::Map<Eigen::Quaternion<double>>(quaternion);
T angleaxis[3];
auxiliary::QuaternionToAngleAxis(quat.coeffs().data(),angleaxis);

QuaternionToAngleAxis is a re-implementation of QuaternionToAngleAxis in rotation.h, which uses the Eigen order (x, y, z, w).

I am getting -nan in all jacobian evaluation.

Regards,

Xiangyu Li

[Sameer Agarwal]

Xiangyu,

It is hard to debug this on the basis of this much information.  You can print the intermediate values in QuarternionToAngleAxis and see where the nan is being introduced.

Sameer

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[Alex Stewart]

This line:

Eigen::Quaternion<T> quat = Eigen::Map<Eigen::Quaternion<double>>(quaternion);

looks suspicious.  Assuming that ‘quaternion' is a T* parameter block then you should not be casting it to a double - that’s going to end badly with T is a Jet.  The line should probably be:

Eigen::Quaternion<T> quat = Eigen::Map<Eigen::Quaternion<T> >(quaternion);

-Alex

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[aeoleader]

I am sorry, that was a typo, in my implementation it was T instead of double... 

[aeoleader]

My method may not be right, is there a better way to do the task? Convert Eigen::Quaternion to T[3] AngleAxis?

Xiangyu 

[Sameer Agarwal]

take the quarternion, convert it to wxyz form and call the conversion routine.

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