ulangl.f

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C*********************************************************************  
    
      FUNCTION ulangl(X,Y)  
    
C...Purpose: to reconstruct an angle from given x and y coordinates.    
      common/ludat1/mstu(200),paru(200),mstj(200),parj(200) 
      SAVE /ludat1/ 
    
      ulangl=0. 
      r=sqrt(x**2+y**2) 
      IF(r.LT.1e-20) RETURN 
      IF(abs(x)/r.LT.0.8) THEN  
        ulangl=sign(acos(x/r),y)    
      ELSE  
        ulangl=asin(y/r)    
        IF(x.LT.0..AND.ulangl.GE.0.) THEN   
          ulangl=paru(1)-ulangl 
        ELSEIF(x.LT.0.) THEN    
          ulangl=-paru(1)-ulangl    
        ENDIF   
      ENDIF 
    
      RETURN    
      END