d4r28.txt

Visual Basic 常用数学算法集书中收录了所有代码

Private Sub Command1_ClicK()
    'PROGRAM D4R28
    'Driver for routine BESIAN
    Dim N(18), VALUE(18), F(18), A(18), X(18)
    Open "D:\VB常用数值算法集\DATA\FNCVAL.DAT" For Input As #1
    Do
      Line Input #1, Text$
    Loop While Text$ <> "Modified Bessel Function Ia+n"
    Line Input #1, NVAL$
    NVAL = Val(NVAL$)
    Print Text$
    Print
    Print "   N     A     IH        X          Actual       BESIAN"
    For I = 0 To NVAL - 1
        Line Input #1, DUM$
        N(I) = Val(Mid(DUM$, 1, 7))
        A(I) = Val(Mid(DUM$, 8, 8))
        X(I) = Val(Mid(DUM$, 16, 8))
        VALUE(I) = Val(Mid(DUM$, 24))
    Next I
    IH = 1
    Call BESIAN(X(0), A(0), 3, IH, F())
    For I = 0 To 3
        Print Tab(4); Format$(N(I), "#0");
        Print Tab(9); Format$(A(I), "0.#");
        Print Tab(16); Format$(IH, "#");
        Print Tab(22); Format$(X(I), "0.000000");
        Print Tab(34); Format$(VALUE(I), ".000000E+00");
        Print Tab(48); Format$(F(I), ".000000E+00");
    Next I
    Call BESIAN(X(4), A(4), 3, IH, F())
    For I = 4 To 7
        Print Tab(4); Format$(N(I), "#0");
        Print Tab(9); Format$(A(I), "0.#");
        Print Tab(16); Format$(IH, "#");
        Print Tab(22); Format$(X(I), "0.000000");
        Print Tab(34); Format$(VALUE(I), ".000000E+00");
        Print Tab(48); Format$(F(I - 4), ".000000E+00");
    Next I
    IH = -1
    Call BESIAN(X(8), A(8), 3, IH, F())
    For I = 8 To 10
        Print Tab(4); Format$(N(I), "#0");
        Print Tab(9); Format$(A(I), "0.#");
        Print Tab(16); Format$(IH, "#");
        Print Tab(22); Format$(X(I), "0.000000");
        Print Tab(34); Format$(VALUE(I), ".000000E+00");
        Print Tab(48); Format$(F(I - 7), ".000000E+00");
    Next I
    Call BESIAN(X(11), A(11), 3, IH, F())
    For I = 11 To 13
        Print Tab(4); Format$(N(I), "#0");
        Print Tab(9); Format$(A(I), "0.#");
        Print Tab(16); Format$(IH, "#");
        Print Tab(22); Format$(X(I), "0.000000");
        Print Tab(34); Format$(VALUE(I), ".000000E+00");
        Print Tab(48); Format$(F(I - 10), ".000000E+00");
    Next I
    Close #1
End Sub