| fe4da5cc |
1 | * |
| 2 | * $Id$ |
| 3 | * |
| 4 | * $Log$ |
| 5 | * Revision 1.1.1.1 1995/10/24 10:22:00 cernlib |
| 6 | * Geant |
| 7 | * |
| 8 | * |
| 9 | #include "geant321/pilot.h" |
| 10 | *CMZ : 3.21/02 29/03/94 15.41.46 by S.Giani |
| 11 | *-- Author : |
| 12 | *$ CREATE COSLEG.FOR |
| 13 | *COPY COSLEG |
| 14 | * |
| 15 | *=== cosleg ===========================================================* |
| 16 | * |
| 17 | FUNCTION COSLEG ( ACOLEG ) |
| 18 | |
| 19 | #include "geant321/dblprc.inc" |
| 20 | #include "geant321/dimpar.inc" |
| 21 | #include "geant321/iounit.inc" |
| 22 | * |
| 23 | *----------------------------------------------------------------------* |
| 24 | *----------------------------------------------------------------------* |
| 25 | * |
| 26 | DIMENSION ACOLEG (0:2) |
| 27 | REAL RNDM(2) |
| 28 | * |
| 29 | IF ( ACOLEG (0) .NE. 0.5D+00 ) THEN |
| 30 | ANORM = 0.5D+00 / ACOLEG (0) |
| 31 | DO 100 I = 0,2 |
| 32 | ACOLEG (I) = ACOLEG (I) * ANORM |
| 33 | 100 CONTINUE |
| 34 | END IF |
| 35 | ACOF = 1.5D+00 * ACOLEG (2) |
| 36 | BCOF = ACOLEG (1) |
| 37 | CCOF = ACOLEG (0) - 0.5D+00 * ACOLEG (2) |
| 38 | FORWRA = 0.3333333333333333D+00 * ACOF |
| 39 | FORWRB = 0.5D+00 * BCOF |
| 40 | FORWRC = CCOF |
| 41 | FORWRD = FORWRA + FORWRB + FORWRC |
| 42 | BACKWR = 1.D+00 - FORWRD |
| 43 | CALL GRNDM(RNDM,1) |
| 44 | RNDCOS = RNDM (1) |
| 45 | IF ( RNDCOS .LT. FORWRD ) THEN |
| 46 | RNDCOS = RNDCOS |
| 47 | IF ( RNDCOS .LT. FORWRA ) THEN |
| 48 | COSLEG = ( RNDCOS / FORWRA )**0.3333333333333333D+00 |
| 49 | ELSE IF ( RNDCOS .LT. FORWRA + FORWRB ) THEN |
| 50 | COSLEG = SQRT ( ( RNDCOS - FORWRA ) / FORWRB ) |
| 51 | ELSE |
| 52 | COSLEG = ( RNDCOS - FORWRA - FORWRB ) / FORWRC |
| 53 | END IF |
| 54 | ELSE |
| 55 | COSLEG = - ( RNDCOS - FORWRD ) / BACKWR |
| 56 | IF ( ACOF .LT. - ANGLGB ) THEN |
| 57 | COSMAX = - 0.5D+00 * BCOF / ACOF |
| 58 | IF ( COSMAX .GT. 0.D+00 ) THEN |
| 59 | PROMAX = CCOF |
| 60 | ELSE IF ( COSMAX .LT. -1.D+00 ) THEN |
| 61 | PROMAX = ACOF - BCOF + CCOF |
| 62 | ELSE |
| 63 | PROMAX = ACOF * COSMAX**2 + BCOF * COSMAX + CCOF |
| 64 | END IF |
| 65 | ELSE IF ( ACOF .GT. ANGLGB ) THEN |
| 66 | IF ( ACOF .GT. BCOF ) THEN |
| 67 | PROMAX = ACOF - BCOF + CCOF |
| 68 | ELSE |
| 69 | PROMAX = CCOF |
| 70 | END IF |
| 71 | ELSE |
| 72 | PROMAX = CCOF |
| 73 | END IF |
| 74 | 200 CONTINUE |
| 75 | FREJE = ( ACOF * COSLEG**2 + BCOF * COSLEG + CCOF ) / PROMAX |
| 76 | CALL GRNDM(RNDM,2) |
| 77 | IF ( RNDM (1) .GE. FREJE ) THEN |
| 78 | COSLEG = - RNDM (2) |
| 79 | GO TO 200 |
| 80 | END IF |
| 81 | END IF |
| 82 | *=== End of subroutine cosleg =========================================* |
| 83 | RETURN |
| 84 | END |
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