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yanyin
Mar14-04, 11:22 PM
Hi, if i want to find a 3x3 matrix R which represents a rotation of Pi/6 around the axis of rotation v(vector)={1, 2, 3}. how can i find it?

Janitor
Mar14-04, 11:42 PM
Are you saying that your axis is along a vector that starts at the origin of the coordinate system and has its tip at the point (x,y,z)=(1,2,3)? And is your rotation direction clockwise or counterclockwise as viewed from the perspective of (0,0,0)?

yanyin
Mar15-04, 12:26 AM
Originally posted by Janitor
Are you saying that your axis is along a vector that starts at the origin of the coordinate system and has its tip at the point (x,y,z)=(1,2,3)? And is your rotation direction clockwise or counterclockwise as viewed from the perspective of (0,0,0)?
Thanks. it's a vector from origin to (1, 2, 3). which direction? i am not sure yet. let say clockwise.

NateTG
Mar15-04, 01:46 AM
Start by figuring out what the result of rotating
[0,0,1]
[0,1,0]
and
[1,0,0]
are.

Once you've done that, you shouldn't have any trouble making hte matrix.

Janitor
Mar15-04, 02:19 AM
This link may or may not help:

http://en.wikipedia.org/wiki/3D_projection

Janitor
Mar15-04, 02:23 AM
http://mathworld.wolfram.com/RotationMatrix.html