1## Copyright (C) 2021 David Legland 2## All rights reserved. 3## 4## Redistribution and use in source and binary forms, with or without 5## modification, are permitted provided that the following conditions are met: 6## 7## 1 Redistributions of source code must retain the above copyright notice, 8## this list of conditions and the following disclaimer. 9## 2 Redistributions in binary form must reproduce the above copyright 10## notice, this list of conditions and the following disclaimer in the 11## documentation and/or other materials provided with the distribution. 12## 13## THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ''AS IS'' 14## AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15## IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16## ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR 17## ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18## DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 19## SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 20## CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 21## OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 22## OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 23## 24## The views and conclusions contained in the software and documentation are 25## those of the authors and should not be interpreted as representing official 26## policies, either expressed or implied, of the copyright holders. 27 28function theta = circle3dPosition(point, circle) 29%CIRCLE3DPOSITION Return the angular position of a point on a 3D circle. 30% 31% POS = circle3dPosition(POINT, CIRCLE) 32% Returns angular position of point on the circle, in degrees, between 0 33% and 360. 34% with POINT: [xp yp zp] 35% and CIRCLE: [X0 Y0 Z0 R THETA PHI] or [X0 Y0 Z0 R THETA PHI PSI] 36% (THETA being the colatitude, and PHI the azimut) 37% 38% See also: 39% circles3d, circle3dOrigin, circle3dPoint 40% 41% --------- 42% author : David Legland 43% INRA - TPV URPOI - BIA IMASTE 44% created the 21/02/2005 45% 46 47% HISTORY 48% 27/06/2007: change 3D angle convention 49% 2011-06-21 use degrees for angles 50 51 52% get center and radius 53xc = circle(:,1); 54yc = circle(:,2); 55zc = circle(:,3); 56 57% get angle of normal 58theta = circle(:,5); 59phi = circle(:,6); 60 61% find origin of the circle 62ori = circle3dOrigin(circle); 63 64% normal vector of the supporting plane (cartesian coords) 65vn = sph2cart2d([theta phi]); 66 67% create plane containing the circle 68plane = createPlane([xc yc zc], vn); 69 70% find position of point on the circle plane 71pp0 = planePosition(ori, plane); 72pp = planePosition(point, plane); 73 74% compute angles in the planes 75theta0 = mod(atan2(pp0(:,2), pp0(:,1)) + 2*pi, 2*pi); 76theta = mod(atan2(pp(:,2), pp(:,1)) + 2*pi - theta0, 2*pi); 77 78% convert to degrees 79theta = theta * 180 / pi; 80