Private Sub Command1_Click()
    'PROGRAM D4R4
    'Driver for routine FACTLN
    Open "D:\VB常用數(shù)值算法集\DATA\FNCVAL.DAT" For Input As #1
    Do
      Line Input #1, Text$
    Loop While Text$ <> "N-factorial"
    Line Input #1, NVAL$
    NVAL = Val(NVAL$)
    Print Text$
    Print
    Print "   N        Actual      FACTLN(N)"
    For I = 1 To NVAL
        Line Input #1, DUM$
        N = Val(Mid(DUM$, 1, 6))
        Value = Val(Mid(DUM$, 8))
        Print Tab(4); Format$(N, "#0");
        Print Tab(12); Format$(Log(Value), "###.000000");
        Print Tab(25); Format$(FACTLN(N), "###.000000")
    Next I
    Close #1
End Sub