pyangl.f

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C*********************************************************************
 
C...PYANGL
C...Reconstructs an angle from given x and y coordinates.
 
      FUNCTION pyangl(X,Y)
 
C...Double precision and integer declarations.
      IMPLICIT DOUBLE PRECISION(a-h, o-z)
      IMPLICIT INTEGER(i-n)
      INTEGER pyk,pychge,pycomp
C...Commonblocks.
      common/pydat1/mstu(200),paru(200),mstj(200),parj(200)
      SAVE /pydat1/
 
      pyangl=0d0
      r=sqrt(x**2+y**2)
      IF(r.LT.1d-20) RETURN
      IF(abs(x)/r.LT.0.8d0) THEN
        pyangl=sign(acos(x/r),y)
      ELSE
        pyangl=asin(y/r)
        IF(x.LT.0d0.AND.pyangl.GE.0d0) THEN
          pyangl=paru(1)-pyangl
        ELSEIF(x.LT.0d0) THEN
          pyangl=-paru(1)-pyangl
        ENDIF
      ENDIF
 
      RETURN
      END