double precision function pinorm(x)
      implicit real*8 (a-h,o-z)
c                                                                      
c this function takes an angle (in radians) and puts it in the range of
c -pi to +pi.                                                         
c                                                                    
      integer n                                                        
      include 'COMMON.GEO'
      n = x / dwapi
      pinorm = x - n * dwapi
      if ( pinorm .gt. pi ) then                                      
         pinorm = pinorm - dwapi
      else if ( pinorm .lt. - pi ) then                               
         pinorm = pinorm + dwapi
      end if                                                          
      return                                                          
      end