Ladnor Geissinger
Posts:
313
From:
University of North Carolina at Chapel Hill
Registered:
12/4/04


Re: rotating a shape in space
Posted:
Dec 3, 2007 10:37 PM


> Suppose that I have 50 pairs of {x,y} values that > form an ellipse centered at {0,0}. How do I do to > rotate this ellipse theta degrees?
The standard matrix of a rotation counterclockwise through an angle t radians is Q(t)=[cos(t),sin(t); sin(t), cos(t)] and of course the transformation takes column vector [x,y]' into Q(t)*[x,y]'. Here if V is a row vector, then V' is the transpose, a column vector.

