Quaternion: Difference between revisions

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Quaternions are a number system which can be used to represent [[rotations]] in 3D space.   
Quaternions are a number system which can be used to represent [[rotations]] in 3D space.
An extension called [[Dual quaternion]], involving quaternions of dual numbers or two quaternions of real numbers, are able to represent both rotations and translations in 3D space.
 
Double quaternion allows representing 4D rotations using two quaternions.   
[[Dual quaternion]] allows represent both rotations and translations in 3D space
The algebra of quaternions, double quaternions, and dual quaternions is called Clifford algebras.


==Background==
==Background==
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==Double Quaternions==
==Double Quaternions==
{{main | Double quaternion}}
Note that double quaternions are different from dual quaternions.   
These are different from dual quaternions.   
Double quaternions are written as <math>q_1 + \epsilon q_2</math> with <math>\epsilon^2 = 1</math>.   
Double quaternions are written as <math>q_1 + \epsilon q_2</math> with <math>\epsilon^2 = 1</math>.   
Dual quaternions are written as <math>q_1 + \varepsilon q_2</math> with <math>\varepsilon^2 = 0</math>.
Dual quaternions are written as <math>q_1 + \varepsilon q_2</math> with <math>\varepsilon^2 = 0</math>.


==Dual Quaternions==
==Dual Quaternions==