PROGRAM d3r12(input,output);
(* driver for routine SPLIE2 *)
CONST
   m=10;
   n=10;
TYPE
   glnarray = ARRAY [1..n] OF real;
   glmbyn = ARRAY [1..m,1..n] OF real;
VAR
   i,j : integer;
   x1x2 : real;
   x1,x2 : glnarray;
   y,y2 : glmbyn;

(*$I MODFILE.PAS *)
(*$I SPLINE.PAS *)

(*$I SPLIE2.PAS *)

BEGIN
   FOR i := 1 to m DO BEGIN
      x1[i] := 0.2*i
   END;
   FOR i := 1 to n DO BEGIN
      x2[i] := 0.2*i
   END;
   FOR i := 1 to m DO BEGIN
      FOR j := 1 to n DO BEGIN
         x1x2 := x1[i]*x2[j];
         y[i,j] := sqr(x1x2)
      END
   END;
   splie2(x1,x2,y,m,n,y2);
   writeln;
   writeln('second derivatives from SPLIE2');
   writeln('natural spline assumed');
   FOR i := 1 to 5 DO BEGIN
      FOR j := 1 to 5 DO write(y2[i,j]:12:6);
      writeln
   END;
   writeln;
   writeln('actual second derivatives');
   FOR i := 1 to 5 DO BEGIN
      FOR j := 1 to 5 DO BEGIN
         x1x2 := x1[i]*x2[i];
         y2[i,j] := 2.0*sqr(x1[i])
      END;
      FOR j := 1 to 5 DO write(y2[i,j]:12:6);
      writeln
   END
END.