Hey everyone .. i hope someone can point me to a solution, i am trying to find the angle between two long bones - known as the Q-angle ( have to process about 6000 x-ray images )
what i want to do is to draw a center line trough the first bone, and a center line through the second bone and then calculate the angle between those two lines. Please how can i approach the problem ?
any help will be appreciated, thanks
You can draw the lines using RBLINE
Roger Stafford recommends this formula for finding the angle between 2 vectors a and b
angle = atan2(norm(cross(a,b)),dot(a,b))*180/pi;
There are some long threads on it in the Newsgroup arguing that it behaves better numerically than other formulas.