subroutine dircos(incl,decl,azim,a,b,c)
c
c  Subroutine DIRCOS computes direction cosines from inclination
c  and declination.
c
c  Input parameters:
c    incl:  inclination in degrees positive below horizontal.  
c    decl:  declination in degrees positive east of true north.  
c    azim:  azimuth of x axis in degrees positive east of north.
c
c  Output parameters:
c    a,b,c:  the three direction cosines.
c
      real incl
      data d2rad/.017453293/
      xincl=incl*d2rad
      xdecl=decl*d2rad
      xazim=azim*d2rad 
      a=cos(xincl)*cos(xdecl-xazim)
      b=cos(xincl)*sin(xdecl-xazim)
      c=sin(xincl)
      return
      end