/*  _______________________________________________________________________
 *
 *                        RDPARM/PTRAJ: APR 2000
 *  _______________________________________________________________________
 *
 *  $Header: /thr/gamow/cvsroot/amber7/src/ptraj/vector.h,v 1.3 2000/05/10 21:52:02 cheatham Exp $
 *
 *  Revision: $Revision: 1.3 $
 *  Date: $Date: 2000/05/10 21:52:02 $
 *  Last checked in by $Author: cheatham $
 *
 *  This source is now archived under CVS at Scripps in the amber7 tree.
 *
 *  NOTE: this is a beta, pre-release version, is under constant development,
 *  probably contains some bugs and is under constant revision; therefore
 *  take care.  Please report bugs (and fixes!) to cheatham@chpc.utah.edu or 
 *  cheatham@cgl.ucsf.edu
 *
 *  Do not distribute this code without explicit permission.
 *  Do not incorporate into other codes without explicit permission.
 *
 *  Current contact information:
 *
 *     Thomas Cheatham, III
 *     2000 East, 30 South, Skaggs Hall 201
 *     Department of Medicinal Chemistry
 *     University of Utah
 *     Salt Lake City, UT 84112-5820
 *     cheatham@chpc.utah.edu
 *     (801) 587-9653
 *     FAX: (801) 585-5366
 *
 *  Other contributors:
 *
 *    David Case (Scripps)
 *    Michael Crowley (Scripps)
 *    Jed Pitera (UCSF)
 *    Vickie Tsui (Scripps)
 *  _______________________________________________________________________
 */


       /* T = U cross V 
        */
#define VOP_3D_COORDS_CROSS_PRODUCT(TX,TY,TZ,UX,UY,UZ,VX,VY,VZ) \
  TX = (UY * VZ) - (UZ * VY); \
  TY = (UZ * VX) - (UX * VZ); \
  TZ = (UX * VY) - (UY * VX)

       /* Multiply the 3x3 matrix times the coordinates specified
        * in x, y and z.  xx, yy and zz are temporary variables.
        * The x, y and z arrays are modified!
        */
#define VOP_3x3_TIMES_COORDS(matrix, x, y, z, xx, yy, zz) \
  xx = matrix[0][0] * x + \
       matrix[0][1] * y + \
       matrix[0][2] * z;  \
  yy = matrix[1][0] * x + \
       matrix[1][1] * y + \
       matrix[1][2] * z;  \
  zz = matrix[2][0] * x + \
       matrix[2][1] * y + \
       matrix[2][2] * z;  \
  x = xx; y = yy; z = zz


       /* Multiply the transpose of the 3x3 matrix times the 
        * coordinates specified in x, y and z.  xx, yy and zz 
        * are temporary variables. 
        * The x, y and z arrays are modified!
        */
#define VOP_3x3_TRANSPOSE_TIMES_COORDS(matrix, x, y, z, xx, yy, zz) \
  xx = matrix[0][0] * x + matrix[1][0] * y + matrix[2][0] * z;  \
  yy = matrix[0][1] * x + matrix[1][1] * y + matrix[2][1] * z;  \
  zz = matrix[0][2] * x + matrix[1][2] * y + matrix[2][2] * z;  \
  x = xx; y = yy; z = zz


#define VOP_3x3_TIMES_3x3(t, u, v) \
  t[0][0] = u[0][0] * v[0][0] + u[0][1] * v[1][0] + u[0][2] * v[2][0]; \
  t[0][1] = u[0][0] * v[0][1] + u[0][1] * v[1][1] + u[0][2] * v[2][1]; \
  t[0][2] = u[0][0] * v[0][2] + u[0][1] * v[1][2] + u[0][2] * v[2][2]; \
  t[1][0] = u[1][0] * v[0][0] + u[1][1] * v[1][0] + u[1][2] * v[2][0]; \
  t[1][1] = u[1][0] * v[0][1] + u[1][1] * v[1][1] + u[1][2] * v[2][1]; \
  t[1][2] = u[1][0] * v[0][2] + u[1][1] * v[1][2] + u[1][2] * v[2][2]; \
  t[2][0] = u[2][0] * v[0][0] + u[2][1] * v[1][0] + u[2][2] * v[2][0]; \
  t[2][1] = u[2][0] * v[0][1] + u[2][1] * v[1][1] + u[2][2] * v[2][1]; \
  t[2][2] = u[2][0] * v[0][2] + u[2][1] * v[1][2] + u[2][2] * v[2][2]