数学算法

				procedure QTRAP(A, B:real; var S:real);
				const
				    EPS = 0.000001;    JMAX = 20;
				var
				    OLDS:real;  J:integer;
				begin
				    OLDS:= -1E+30;
				    For J:= 1 To JMAX do
				    begin
				        TRAPZD(A, B, S, J);
				        If (Abs(S - OLDS) < (EPS * Abs(OLDS))) Then Exit;
				        OLDS:= S;
				    end;
				    ShowMessage('Too many steps.');
				end;