begin
  NX = 21
  NY = 21
;
; Define the input data arrays.
;
  x = (/0.00, 1.00, 0.00, 1.00, 0.40, 0.75/)
  y = (/0.00, 0.00, 1.00, 1.00, 0.20, 0.65/)
  z = (/0.00, 0.00, 0.00, 0.00, 1.25, 0.80/)
;
; Define the output grid.
;
  xc = 1./(NX-1.) 
  xo = ispan(0,NX-1,1) * xc

  yc = 1./(NY-1.) 
  yo = ispan(0,NY-1,1) * yc

;
; Do the gridding using natgrids. "natout" will be a 2-dimensional array
; dimensioned 21 x 21.
;
  natout = natgrids(x, y, z, xo, yo)
  print(natout)

;
; Do the gridding using dsgrid2s. "dsout" will be a 2-dimensional array
; dimensioned 21 x 21.
;
  dsout = dsgrid2s(x, y, z, xo, yo)
  print(dsout)
end