makeRegionAxisFast

 makeRegionAxis : calculates the principal axis of the segment mask.

 INPUT :
       angle_deg : orientation of segment
 OUTPUT :
       e1 : aligned with the major axis
       e2 : aligned with the minor axis 


 Copyright (C) 2016 Wiggins Lab 
 Written by Paul Wiggins.
 University of Washington, 2016
 This file is part of SuperSegger.
 
 SuperSegger is free software: you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
 the Free Software Foundation, either version 3 of the License, or
 (at your option) any later version.
 
 SuperSegger is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU General Public License for more details.
 
 You should have received a copy of the GNU General Public License
 along with SuperSegger.  If not, see <http://www.gnu.org/licenses/>.

0001 function [e1,e2] = makeRegionAxisFast( angle_deg )
0002 % makeRegionAxis : calculates the principal axis of the segment mask.
0003 %
0004 % INPUT :
0005 %       angle_deg : orientation of segment
0006 % OUTPUT :
0007 %       e1 : aligned with the major axis
0008 %       e2 : aligned with the minor axis
0009 %
0010 %
0011 % Copyright (C) 2016 Wiggins Lab
0012 % Written by Paul Wiggins.
0013 % University of Washington, 2016
0014 % This file is part of SuperSegger.
0015 %
0016 % SuperSegger is free software: you can redistribute it and/or modify
0017 % it under the terms of the GNU General Public License as published by
0018 % the Free Software Foundation, either version 3 of the License, or
0019 % (at your option) any later version.
0020 %
0021 % SuperSegger is distributed in the hope that it will be useful,
0022 % but WITHOUT ANY WARRANTY; without even the implied warranty of
0023 % MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
0024 % GNU General Public License for more details.
0025 %
0026 % You should have received a copy of the GNU General Public License
0027 % along with SuperSegger.  If not, see <http://www.gnu.org/licenses/>.
0028 
0029 theta = -(180+angle_deg)*pi/180;
0030 e1   = [ cos(theta), sin(theta)];
0031 e2   = [-sin(theta), cos(theta)];
0032 
0033 end