*
* $Id$
*
* $Log$
* Revision 1.1.1.1  1996/04/01 15:02:29  mclareni
* Mathlib gen
*
*
#include "gen/pilot.h"
      SUBROUTINE POLROT(THETA,PHI,THPRIM,PHPRIM,THAXE,PHAXE,ROTANG)
C
C     SUBROUTINE POUR CALCULER UNE ROTATION EN COORDONNEES POLAIRES
C
C     THAXE,PHAXE=DIRECTION DE L#AXE,ROTANG=ANGLE DE ROTATION
C
C     PI=3.14159265
C
C     SI THPRIM = 0.0,PHPRIM A N#IMPORTE QUELLE VALEUR
C
      DIMENSION X(3),TENSO1(3),TENSO2(3),TENSO3(3)
      DATA PI/3.14159265/,PIHALF/1.57079633/
      A=COS(ROTANG)
      B=1.0-A
      C=SIN(ROTANG)
      AX=SIN(THAXE)
      E1=AX*COS(PHAXE)
      E2=AX*SIN(PHAXE)
      E3=COS(THAXE)
      ET=SIN(THETA)
      X(1)=ET*COS(PHI)
      X(2)=ET*SIN(PHI)
      X(3)=COS(THETA)
      B12=B*E1*E2
      B13=B*E1*E3
      B23=B*E2*E3
      C1=C*E1
      C2=C*E2
      C3=C*E3
      TENSO1(1)=A+B*E1**2
      TENSO1(2)=B12+C3
      TENSO1(3)=B13-C2
      TENSO2(1)=B12-C3
      TENSO2(2)=A+B*E2**2
      TENSO2(3)=B23+C1
      TENSO3(1)=B13+C2
      TENSO3(2)=B23-C1
      TENSO3(3)=A+B*E3**2
      Y1=0.0
      Y2=0.0
      Y3=0.0
      DO 3 K=1,3
      Y1=Y1+TENSO1(K)*X(K)
      Y2=Y2+TENSO2(K)*X(K)
    3 Y3=Y3+TENSO3(K)*X(K)
      IF(Y1.NE.0.OR.Y2.NE.0.)GO TO 12
      PHPRIM=0.0
      THPRIM=PIHALF-SIGN(PIHALF,Y3)
      GO TO 13
   12 PHPRIM=ATAN2(Y2,Y1)
      IF(PHPRIM)1,2,2
    1 PHPRIM=PHPRIM+2.0*PI
    2 CONTINUE
      IF(Y1.NE.0.OR.Y3.NE.0.)GO TO 15
      THPRIM=PIHALF
      GO TO 13
   15 COPHPR=COS(PHPRIM)
      IF(ABS(COPHPR).LT.0.7)GO TO 5
      THPRIM=ATAN2(Y1/COS(PHPRIM),Y3)
      GO TO 13
    5                  THPRIM=ATAN2(Y2/SIN(PHPRIM),Y3)
   13 RETURN
      END