[u/mrichter/AliRoot.git] / GEANT321 / fluka / trans.F

*
* $Id$
*
* $Log$
* Revision 1.1.1.1  1995/10/24 10:20:04  cernlib
* Geant
*
*
#include "geant321/pilot.h"
*CMZ :  3.21/02 29/03/94  15.41.44  by  S.Giani
*-- Author :
*$ CREATE TRANS.FOR
*COPY TRANS
*  FLUPDATE FORTRAN file
*  These are corrected versions of TRANS and TTRANS which make the
*  correct transformation even in the small-angle, backwards direction
*  Correction installed 11.03.88
      SUBROUTINE TRANS (XO,YO,ZO,DE,SFE,CFE,X,Y,Z)
 
#include "geant321/dblprc.inc"
#include "geant321/dimpar.inc"
#include "geant321/iounit.inc"
C********************************************************************
C     VERSION BY                     J. RANFT
C                                    LEIPZIG
C     LAST CHANGE 12. APRIL 83    BY PERTTI AARNIO
C                                    HELSINKI UNIVERSITY OF
C                                    TECHNOLOGY, FINLAND
C
C
C     THIS IS A SUBROUTINE OF FLUKA TO GIVE NEW DIRECTION COSINES
C
C     INPUT VARIABLES:
C        XO,YO,ZO = ORIGINAL DIRECTION COSINES
C        DE       = POLAR (THETA) ANGLE OF "SCATTERING"
C        SFE,CFE  = SINE AND COSINE OF THE AZIMUTHAL (PHI) ANGLE
C                   OF "SCATTERING"
C
C     OUTPUT VARIABLES:
C        X,Y,Z     = NEW DIRECTION COSINES
C
C     ROTATION OF COORDINATE SYSTEM (SEE CERN 64-47)
C
C     DUE TO THE IMPLEMENTATION OF THE MULTIPLE COULOMB SCATTERING
C     ALSO VERY SMALL ANGLES HAVE TO BE TREATED CORRECTLY.
C     NOW SMALL ANGLE APPROXIMATION IS USED PRACTICALLY ONLY
C     WHEN XO AND YO ARE EXACTLY 0.
C
C********************************************************************
C
*
      CDE=COS(DE)
      SDE=SIN(DE)
      A = XO**2 + YO**2
      IF ( A .LT. ANGLSQ ) THEN
         X=SDE*CFE
         Y=SDE*SFE
C   Z=CDE CORRECTED AUGUST 88 PA
         Z=CDE*ZO
      ELSE
         XI=SDE*CFE
         YI=SDE*SFE
         ZI=CDE
         A =SQRT(A)
         X=-YO*XI/A-ZO*XO*YI/A+XO*ZI
         Y=XO*XI/A-ZO*YO*YI/A+YO*ZI
         Z=A*YI+ZO*ZI
      END IF
      RETURN
      END
Commit	Line	Data
fe4da5cc	1	*
	2	* $Id$
	3	*
	4	* $Log$
	5	* Revision 1.1.1.1 1995/10/24 10:20:04 cernlib
	6	* Geant
	7	*
	8	*
	9	#include "geant321/pilot.h"
	10	*CMZ : 3.21/02 29/03/94 15.41.44 by S.Giani
	11	*-- Author :
	12	*$ CREATE TRANS.FOR
	13	*COPY TRANS
	14	* FLUPDATE FORTRAN file
	15	* These are corrected versions of TRANS and TTRANS which make the
	16	* correct transformation even in the small-angle, backwards direction
	17	* Correction installed 11.03.88
	18	SUBROUTINE TRANS (XO,YO,ZO,DE,SFE,CFE,X,Y,Z)
	19
	20	#include "geant321/dblprc.inc"
	21	#include "geant321/dimpar.inc"
	22	#include "geant321/iounit.inc"
	23	C********************************************************************
	24	C VERSION BY J. RANFT
	25	C LEIPZIG
	26	C LAST CHANGE 12. APRIL 83 BY PERTTI AARNIO
	27	C HELSINKI UNIVERSITY OF
	28	C TECHNOLOGY, FINLAND
	29	C
	30	C
	31	C THIS IS A SUBROUTINE OF FLUKA TO GIVE NEW DIRECTION COSINES
	32	C
	33	C INPUT VARIABLES:
	34	C XO,YO,ZO = ORIGINAL DIRECTION COSINES
	35	C DE = POLAR (THETA) ANGLE OF "SCATTERING"
	36	C SFE,CFE = SINE AND COSINE OF THE AZIMUTHAL (PHI) ANGLE
	37	C OF "SCATTERING"
	38	C
	39	C OUTPUT VARIABLES:
	40	C X,Y,Z = NEW DIRECTION COSINES
	41	C
	42	C ROTATION OF COORDINATE SYSTEM (SEE CERN 64-47)
	43	C
	44	C DUE TO THE IMPLEMENTATION OF THE MULTIPLE COULOMB SCATTERING
	45	C ALSO VERY SMALL ANGLES HAVE TO BE TREATED CORRECTLY.
	46	C NOW SMALL ANGLE APPROXIMATION IS USED PRACTICALLY ONLY
	47	C WHEN XO AND YO ARE EXACTLY 0.
	48	C
	49	C********************************************************************
	50	C
	51	*
	52	CDE=COS(DE)
	53	SDE=SIN(DE)
	54	A = XO2 + YO2
	55	IF ( A .LT. ANGLSQ ) THEN
	56	X=SDE*CFE
	57	Y=SDE*SFE
	58	C Z=CDE CORRECTED AUGUST 88 PA
	59	Z=CDE*ZO
	60	ELSE
	61	XI=SDE*CFE
	62	YI=SDE*SFE
	63	ZI=CDE
	64	A =SQRT(A)
65	X=-YOXI/A-ZOXOYI/A+XOZI
66	Y=XOXI/A-ZOYOYI/A+YOZI
67	Z=AYI+ZOZI
68	END IF
69	RETURN
70	END