unit2.pas

来自「1、说明： 本书中所有的常用数值算法子过程按书中的章数分别放在以C开头」· PAS 代码 · 共 34 行

unit Unit2;

interface
USES
  UNIT1;
procedure CHEBFT(A, B:real; var C:array of real; N:integer);
implementation
procedure CHEBFT(A, B:real; var C:array of real; N:integer);
var
       K,J:integer;  SUM,Y,BMA,BPA,FAC:real;
       F:array[0..50] of real;
const
       NMAX = 50;    PI = 3.14159265358979;
begin
    BMA:=0.5 * (B - A);
    BPA:=0.5 * (B + A);
    For K:=1 To N do
       begin
        Y:=Cos(PI * (K - 0.5) / N);
        F[K]:=FUNC(Y * BMA + BPA);
    end;
    FAC:=2/ N;
    For J:=1 To N do
       begin
        Sum:=0 ;
        For K:=1 To N do
              begin
            Sum:=Sum + F[K] * Cos((PI * (J - 1)) * ((K - 0.5) / N));
        end;
        C[J]:=FAC * Sum;
    end;
end;
end.