[u/mrichter/AliRoot.git] / GEANT321 / ghits / gcubs.F

*
* $Id$
*
* $Log$
* Revision 1.1.1.1  1995/10/24 10:21:08  cernlib
* Geant
*
*
#include "geant321/pilot.h"
*CMZ :  3.21/02 29/03/94  15.41.20  by  S.Giani
*-- Author :
      SUBROUTINE GCUBS(X,Y,D1,D2,A)
C.
C.
C.    ******************************************************************
C.    *                                                                *
C.    *       Calculates a cubic through P1,(-X,Y1),(X,Y2),P2          *
C.    *       where Y2=-Y1                                             *
C.    *        Y=A(1)+A(2)*X+A(3)*X**2+A(4)*X**3                       *
C.    *        The coordinate system is assumed to be the cms system   *
C.    *        of P1,P2.                                               *
C.    *                                                                *
C.    *    ==>Called by : GIPLAN,GICYL                                 *
C.    *       Author    H.Boerner  *********                           *
C.    *                                                                *
C.    ******************************************************************
C.
      REAL X,Y,D1,D2,A(4)
C.
C.
C.    ------------------------------------------------------------------
C.
C.
      IF (X.EQ.0.)                               GO TO 10
C
C
      FACT   = (D1 - D2) * 0.25
      A(1)   = - 1. * FACT * X
      A(3)   = FACT / X
      A(2)   = (6. * Y - (D1 + D2) * X) / (4. * X)
      A(4)   = ((D1 + D2)*X - 2.*Y) / (4.*X**3)
      RETURN
C
  10  A(1)   = 0.
      A(2)   = 1.
      A(3)   = 0.
      A(4)   = 0.
      END
Commit	Line	Data
fe4da5cc	1	*
	2	* $Id$
	3	*
	4	* $Log$
	5	* Revision 1.1.1.1 1995/10/24 10:21:08 cernlib
	6	* Geant
	7	*
	8	*
	9	#include "geant321/pilot.h"
	10	*CMZ : 3.21/02 29/03/94 15.41.20 by S.Giani
	11	*-- Author :
	12	SUBROUTINE GCUBS(X,Y,D1,D2,A)
	13	C.
	14	C.
	15	C. ******************************************************************
	16	C. * *
	17	C. * Calculates a cubic through P1,(-X,Y1),(X,Y2),P2 *
	18	C. * where Y2=-Y1 *
	19	C. * Y=A(1)+A(2)X+A(3)X*2+A(4)X*3
	20	C. * The coordinate system is assumed to be the cms system *
	21	C. * of P1,P2. *
	22	C. * *
	23	C. * ==>Called by : GIPLAN,GICYL *
	24	C. * Author H.Boerner ********* *
	25	C. * *
	26	C. ******************************************************************
	27	C.
	28	REAL X,Y,D1,D2,A(4)
	29	C.
	30	C.
	31	C. ------------------------------------------------------------------
	32	C.
	33	C.
	34	IF (X.EQ.0.) GO TO 10
	35	C
	36	C
	37	FACT = (D1 - D2) * 0.25
	38	A(1) = - 1. * FACT * X
	39	A(3) = FACT / X
	40	A(2) = (6. * Y - (D1 + D2) * X) / (4. * X)
	41	A(4) = ((D1 + D2)X - 2.Y) / (4.X*3)
	42	RETURN
	43	C
	44	10 A(1) = 0.
	45	A(2) = 1.
	46	A(3) = 0.
	47	A(4) = 0.
	48	END