PDA

View Full Version : Re: Calculation of 2D Angles ('CAST' problem)



Ulrich Simon
12-18-2002, 08:09 PM
Dear Dr. Kirtley,

Are you able to use the ATAN2 Function? The ATAN2 function is
implemented in most of the standard program languages (C, MatLab,
FORTRAN, &). This function is called with two arguments instead of only
one argument.
Use: alpha = ATAN2(Y, X) in the range ( Pi < alpha < Pi)
Instead of: alpha = ATAN(Z); Z = Y/X in the range ( Pi/2 < alpha < Pi/2)
However, internally the ATAN2 function does nothing else than your self
written tool: determining the particular quadrant from the signs of the
two arguments. There is definitely no other way to calculate it.

Best regards
Ulrich Simon

------------------------------------------------------------
Dr.-Ing. Ulrich Simon
Institute of Orthopaedic Research and Biomechanics
University of Ulm
www.biomechanics.de
-------------------------------------------------------------

---------------------------------------------------------------
To unsubscribe send SIGNOFF BIOMCH-L to LISTSERV@nic.surfnet.nl
For information and archives: http://isb.ri.ccf.org/biomch-l
---------------------------------------------------------------