subroutine kutl_boost_from_frame(w_in, velocity, w_out)
*
* begin_doc
*
*  Boost a W track from a frame moving with a specified velocity. Only
*  the momentum and energy components are modified.
*
*  Note: this routine is the inverse of kutl_boost_to_frame..
*
*  Input Parameters:
*  w_in(10)       double precision array
*                 Input track parameters
*
*  velocity(3)    double precision array
*                 Velocity of frame to boost from
*
*  Output Parameters:
*  w_out(10)      double precision array
*                 Output track parameters
*
*
*  Other routines:
*
*  Notes:
*
*  >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
*   The momemtum components in the unboosted frame are (variables marked
*   with a * are in the boosted frame):
*
*       Px  = Px* + gam * vx [E* + gam/(gam+1) * v o P*]
*       Py  = Py* + gam * vy [E* + gam/(gam+1) * v o P*]
*       Pz  = Pz* + gam * vz [E* + gam/(gam+1) * v o P*]
*        E  = gam * [E* + v o P*]
*
*   where v o P* is the 3-dot product of the velocity boost and the
*   momentum.
*  >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
*
*  Author:   Paul Avery      Created:  Mon Dec  8 21:26:06 EST 1997
*
*  Major revisions:
*
*
* end_doc