Imported healpix tree

external/healpix/cxxsupport/rotmatrix.h

@@ -0,0 +1,158 @@
+/*
+ *  This file is part of libcxxsupport.
+ *
+ *  libcxxsupport 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 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  libcxxsupport 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 libcxxsupport; if not, write to the Free Software
+ *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+/*
+ *  libcxxsupport is being developed at the Max-Planck-Institut fuer Astrophysik
+ *  and financially supported by the Deutsches Zentrum fuer Luft- und Raumfahrt
+ *  (DLR).
+ */
+
+/*! \file rotmatrix.h
+ *  Class for rotation transforms in 3D space
+ *
+ *  Copyright (C) 2003 Max-Planck-Society
+ *  \author Martin Reinecke
+ */
+
+#ifndef PLANCK_ROTMATRIX_H
+#define PLANCK_ROTMATRIX_H
+
+#include <iostream>
+#include "cxxutils.h"
+#include "vec3.h"
+
+/*! \defgroup rotmatrixgroup Rotation matrices */
+/*! \{ */
+
+/*! Class for rotation transforms in 3D space */
+class rotmatrix
+  {
+  public:
+    double entry[3][3];
+
+    rotmatrix () {}
+
+    /*! Constructs a rotation matrix from its nine entries */
+    rotmatrix (double a00, double a01, double a02,
+               double a10, double a11, double a12,
+               double a20, double a21, double a22)
+      {
+      entry[0][0]=a00; entry[0][1]=a01; entry[0][2]=a02;
+      entry[1][0]=a10; entry[1][1]=a11; entry[1][2]=a12;
+      entry[2][0]=a20; entry[2][1]=a21; entry[2][2]=a22;
+      }
+
+    /*! Constructs a rotation matrix so that \a a is the first column,
+        \a b is the second column and \a c is the third column.
+        \note The vectors \a a, \a b and \a c must form an orthonormal system!
+     */
+    rotmatrix (const vec3 &a, const vec3 &b, const vec3 &c);
+
+    /*! Sets the matrix to the identity matrix. */
+    void SetToIdentity ();
+    /*! Sets all matrix elements to zero. */
+    void SetToZero ();
+    /*! Transposes the matrix. */
+    void Transpose ();
+
+    /*! Extracts a unit-length rotation axis \a axis and a rotation angle
+        \a angle from the matrix. */
+    void toAxisAngle (vec3 &axis, double &angle) const;
+
+    /*! Constructs a matrix which causes a rotation by \a angle around
+        \a axis. \a axis must have unit length. */
+    void Make_Axis_Rotation_Transform (const vec3 &axis, double angle)
+      {
+      double sa=sin(angle), ca=cos(angle);
+      double ica=1-ca;
+      entry[0][0] = axis.x*axis.x*ica + ca;
+      entry[1][1] = axis.y*axis.y*ica + ca;
+      entry[2][2] = axis.z*axis.z*ica + ca;
+      double t1 = axis.x*axis.y*ica, t2 = axis.z*sa;
+      entry[1][0] = t1 + t2;
+      entry[0][1] = t1 - t2;
+      t1 = axis.x*axis.z*ica; t2 = axis.y*sa;
+      entry[2][0] = t1 - t2;
+      entry[0][2] = t1 + t2;
+      t1 = axis.y*axis.z*ica; t2 = axis.x*sa;
+      entry[1][2] = t1 - t2;
+      entry[2][1] = t1 + t2;
+      }
+
+    /*! Creates a rotation matrix \a A, which performs the following operations
+        on a vector \a v, when \a Av is calculated:
+        -# rotate \a v around the z-axis by \a gamma,
+        -# rotate \a v' around the y-axis by \a beta,
+        -# rotate \a v'' around the z-axis by \a alpha.
+
+        \note \a alpha, \a beta and \a gamma are given in radians,
+              the rotations are right handed.
+
+        \note This transformation rotates the \e vectors, not the coordinate
+              axes! */
+    void Make_CPAC_Euler_Matrix (double alpha, double beta, double gamma);
+
+    /*! Extracts the Euler angles \a alpha, \a beta and \a gamma from the
+        matrix. For their definition see Make_CPAC_Euler_Matrix().
+
+        \note In case of ambiguity \a alpha will be 0. */
+    void Extract_CPAC_Euler_Angles
+      (double &alpha, double &beta, double &gamma) const;
+
+    /*! Returns the vector \a vec, transformed by the matrix. */
+    vec3 Transform (const vec3 &vec) const
+      {
+      return vec3
+        (vec.x*entry[0][0] + vec.y*entry[0][1] + vec.z*entry[0][2],
+         vec.x*entry[1][0] + vec.y*entry[1][1] + vec.z*entry[1][2],
+         vec.x*entry[2][0] + vec.y*entry[2][1] + vec.z*entry[2][2]);
+      }
+    /*! Returns the vector \a vec, transformed by the matrix, in \a vec2. */
+    void Transform (const vec3 &vec, vec3 &vec2) const
+      {
+      vec2.x = vec.x*entry[0][0] + vec.y*entry[0][1] + vec.z*entry[0][2];
+      vec2.y = vec.x*entry[1][0] + vec.y*entry[1][1] + vec.z*entry[1][2];
+      vec2.z = vec.x*entry[2][0] + vec.y*entry[2][1] + vec.z*entry[2][2];
+      }
+  };
+
+/*! Returns \a a * \a b.
+    \relates rotmatrix */
+rotmatrix operator* (const rotmatrix &a, const rotmatrix &b);
+/*! Returns \a a * \a b in \a res.
+    \relates rotmatrix */
+inline void matmult (const rotmatrix &a, const rotmatrix &b, rotmatrix &res)
+  {
+  for (int i=0; i<3; ++i)
+    for (int j=0; j<3; ++j)
+      res.entry[i][j] = a.entry[i][0] * b.entry[0][j]
+                      + a.entry[i][1] * b.entry[1][j]
+                      + a.entry[i][2] * b.entry[2][j];
+  }
+
+/*! Returns \a a^T * \a b in \a res.
+    \relates rotmatrix */
+void TransposeTimes (const rotmatrix &a, const rotmatrix &b, rotmatrix &res);
+
+/*! Writes \a mat to \a os.
+    \relates rotmatrix */
+std::ostream &operator<< (std::ostream &os, const rotmatrix &mat);
+
+/*! \} */
+
+#endif