delphi数值算法集光盘源代码,用于delphi7科学出版社出版.

				implementation
				//PROGRAM D12R3
				//Driver for routine RKQC
				uses
				  unit2;
				  {$R *.DFM}
				procedure DERIVS(X:real; Y:array of real;var DYDX:array of real);
				begin
				    DYDX[1]:= -Y[2];
				    DYDX[2]:= Y[1] - (1 / X) * Y[2];
				    DYDX[3]:= Y[2] - (2 / X) * Y[3];
				    DYDX[4]:= Y[3] - (3 / X) * Y[4];
				end;
				procedure TForm1.Button1Click(Sender: TObject);
				const
				  s1='%14.6f';  N = 4;
				var
				  F:TextFile;
				  Y,DYDX,YSCAL:array[0..N] of real;
				  I:integer;   X,HTRY,EPS,HDID,HNEXT:real;
				begin
				  X:=1.0;
				  Y[1]:= BESSJ0(X);
				  Y[2]:= BESSJ1(X);
				  Y[3]:= BESSJ(2, X);
				  Y[4]:= BESSJ(3, X);
				  DYDX[1]:= -Y[2];
				  DYDX[2]:= Y[1] - Y[2];
				  DYDX[3]:= Y[2] - 2*Y[3];
				  DYDX[4]:= Y[3] - 3*Y[4];
				  //输出计算结果到文件
				  AssignFile(F, 'd:\delphi_shu\p12\d12r3.dat');
				  Rewrite(F);
				  Writeln(F);
				  Writeln(F,'      eps      htry        hdid         hnext');
				  For I:= 1 To N do
				    YSCAL[I]:= 1;
				  HTRY:= 0.1;
				  For I:= 1 To 15 do
				  begin
				    EPS:= Exp(-I);
				    RKQC(Y, DYDX, N, X, HTRY, EPS, YSCAL, HDID, HNEXT);
				    Writeln(F,'  ',FormatFloat('.###0E+00',EPS),Format('%8.2f',[HTRY]),
				                                 Format(s1,[HDID]),Format(s1,[HNEXT]));
				  end;
				  CloseFile(F);
				  //屏幕显示计算结果
				  memo1.Lines.LoadFromFile('d:\delphi_shu\p12\d12r3.dat');
				end;