scrsho.txt

常用的数值算法的VB程序

Sub SCRSHO(DUM)
    ISCR% = 60
    JSCR% = 21
    Dim Y(60), SCR$(60, 21)
    BLANK$ = " "
    ZERO$ = "-"
    YY$ = "1"
    XX$ = "-"
    FF$ = "x"
    'Enter X1,X2 (X1=X2 to stop)
    X1 = -5#
    X2 = 5#
    If X1 = X2 Then Exit Sub
    For J = 1 To JSCR%
        SCR$(1, J) = YY$
        SCR$(ISCR%, J) = YY$
    Next J
    For I = 2 To ISCR% - 1
        SCR$(I, 1) = XX$
        SCR$(I, JSCR%) = XX$
        For J = 2 To JSCR% - 1
            SCR$(I, J) = BLANK$
        Next J
    Next I
    DX = (X2 - X1) / (ISCR% - 1)
    X = X1
    YBIG = 0#
    YSML = YBIG
    For I = 1 To ISCR%
        Y(I) = FUNC(X)
        If Y(I) < YSML Then YSML = Y(I)
        If Y(I) > YBIG Then YBIG = Y(I)
        X = X + DX
    Next I
    If YBIG = YSML Then YBIG = YSML + 1#
    DYJ = (JSCR% - 1) / (YBIG - YSML)
    JZ = 1 - YSML * DYJ
    For I = 1 To ISCR%
        SCR$(I, JZ) = ZERO$
        J = 1 + (Y(I) - YSML) * DYJ
        SCR$(I, J) = FF$
    Next I
    Print Format$(YBIG, "##.#######");
    Print " ";
    For I = 1 To ISCR%
        Print SCR$(I, JSCR%);
    Next I
    Print
    For J = JSCR% - 1 To 2 Step -1
        Print "         ";
        For I = 1 To ISCR%
            Print SCR$(I, J);
        Next I
        Print
    Next J
    Print Format$(YSML, "##.######");
    Print " ";
    For I = 1 To ISCR%
        Print SCR$(I, 1);
    Next I
    Print
    Print "         ";
    Print Format$(X1, "##.#######");
    Print Tab(70);
    Print Format$(X2, "##.#######")
End Sub