locate.dem

Delphi Pascal 数据挖掘领域算法包 数值算法大全

PROGRAM d3r5 (input,output);
(* driver for routine LOCATE *)
CONST
   n=100;
TYPE
   glnarray = ARRAY [1..n] OF real;
VAR
   i,j : integer;
   x : real;
   xx : glnarray;

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

BEGIN
(* create array to be searched *)
   FOR i := 1 to n DO BEGIN
      xx[i] := exp(i/20.0)-74.0
   END;
   writeln ('result of:  j := 0 indicates x too small');
   writeln (' ':12,'j := 100 indicates x too large');
   writeln;
   writeln ('locate ':10,'j':6,'xx(j)':11,'xx(j+1)':12);
(* do test *)
   FOR i := 1 to 19 DO BEGIN
      x := -100.0+200.0*i/20.0;
      locate(xx,n,x,j);
      IF ((j<n) AND (j>0)) THEN BEGIN
         writeln (x:10:4,j:6,xx[j]:12:6,xx[j+1]:12:6)
      END ELSE IF (j=n) THEN BEGIN
         writeln (x:10:4,j:6,xx[j]:12:6,'   upper lim')
      END ELSE BEGIN
         writeln (x:10:4,j:6,'   lower lim',xx[j+1]:12:6)
      END
   END
END.