What is Quaternion and where is it used?

What is quaternion ? and what it is used for ?
any tutorials or books about quaternion plz

Re: Q: Quaternion?

I think it is normal cartesian coordinates used with together with the angle. The way I look at it is like a normal vector with some rotation attribute(angle) based on some axis of rotation. Have been a while so i could not remember too clearly. Came across it in some computer vision course to convert the normal cartesian case for evaluation. i think to solve for some projective geometry question


https://en.wikipedia.org/wiki/Quaternion

Q: Quaternion?

compleax number is a two dimensional number, quaternion is a 4 dimensional number

Re: Q: Quaternion?

see this link

**broken link removed**

Q: Quaternion?

some high level commentary:

typically quaternion math is used because it can describe a rotation by multiplying two quaternions together. very efficient algorithm that does not have any singularity problems.

for this reason you often find its use in computer graphics and navigation (6-axis of freedom).

think of quaternion math as a higher order mathematics, like one step higher than calculus. one step lower than calculus would be Tensors.

there is some debate on if the quaternion has "time" associated with it. calculus has time --> dV/dt and all that, but quaternions deal with time in a different way. Roger Penrose (probably the smartest guy on the planet today) does not believe it does. my personal opinion is that quaternions DO contain an element of "time" but only if one defines "time" by MORE than just the "stuff that happens between two events" but rather defined by quantifiable characteristics, both real and imaginary (non-spacial).

i have never found any books on the subject, but if you come across any please post!

Mr.Cool