subroutine grid(nzones, xmin, xmax, xa, dx)
C
C Create grid to cover physical size from xmin to xmax
C number of physical grid zones is nzones
C
C xa(1) is left boundary location - at xmin
C xa(nzones+1) is right boundary location - at xmax
C
      integer nzones
      real xmin, xmax
      real xa(nzones), dx(nzones)
C
C LOCALS
C
      real dxfac
      integer n
C
C=======================================================================
C
      dxfac = (xmax-xmin)/float(nzones)
C
      do 1 n = 1, nzones
         xa(n) = xmin + (n-1)*dxfac
         dx(n) = dxfac
  1   continue
C
      return
      end