rotation_about_axes_zxz_mapping.h

/* Copyright (C) 2004-2009 MBSim Development Team
 *
 * This library is free software; you can redistribute it and/or 
 * modify it under the terms of the GNU Lesser General Public 
 * License as published by the Free Software Foundation; either 
 * version 2.1 of the License, or (at your option) any later version. 
 *  
 * This library 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 
 * Lesser General Public License for more details. 
 *  
 * You should have received a copy of the GNU Lesser General Public 
 * License along with this library; if not, write to the Free Software 
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA
 *
 * Contact: martin.o.foerg@gmail.com
 */
 
#ifndef _ROTATION_ABOUT_AXES_ZXZ_MAPPING_H_
#define _ROTATION_ABOUT_AXES_ZXZ_MAPPING_H_
 
#include "mbsim/functions/function.h"
 
namespace MBSim {
 
  template<class Arg> 
  class RotationAboutAxesZXZMapping : public Function<fmatvec::MatV(Arg)> {
    private:
      fmatvec::MatV T;
    public:
      RotationAboutAxesZXZMapping() : T(3,3) { T.e(0,2) = 1; }
      int getArgSize() const override { return 3; }
      fmatvec::MatV operator()(const Arg &q) override {
        double psi = q.e(0);
        double theta = q.e(1);
        double cos_theta = cos(theta);
        double sin_theta = sin(theta);
        if(fabs(sin_theta)<=1e-13)
          Element::throwError("Singularity in rotation.");
        double cos_psi = cos(psi);
        double sin_psi = sin(psi);
        double tan_theta = sin_theta/cos_theta;
 
        T.e(0,0) = -sin_psi/tan_theta;
        T.e(0,1) = cos_psi/tan_theta;
        T.e(1,0) = cos_psi;
        T.e(1,1) = sin_psi;
        T.e(2,0) = sin_psi/sin_theta;
        T.e(2,1) = -cos_psi/sin_theta;
 
        return T;
      }
  };
 
}
 
#endif