d5r1.txt

来自「本书共有数值计算中常用的VisualBasic子过程近200个」· 文本 代码 · 共 27 行

Private Sub Command1_Click()
    'PROGRAM D5R1
    'Driver for routine EULSUM
    NVAL = 40
    Dim WKSP(40)
    'Evaluate ln(1+x)=x-x^2/2+x^3/3-x^4/4... for -1<x<1
    Print
    Print Tab(5); "How many terms in polynomial?"
    'Input MVAL , between 1 and 40, MVAL=0 TO END
    MVAL = 20
    Print Tab(5); MVAL
    If (MVAL <= 0) Or (MVAL > NVAL) Then Exit Sub
    Print Tab(5); "  X        Actual      Polynomial"
    For I = -8 To 8 Step 1
        X = I / 10#
        SUM = 0#
        XPOWER = -1#
        For J = 1 To MVAL
            XPOWER = -X * XPOWER
            TERM = XPOWER / J
            Call EULSUM(SUM, TERM, J, WKSP())
        Next J
        Print Tab(4); Format$(X, ".##000");
        Print Tab(15); Format$(Log(1# + X), "#.###000");
        Print Tab(29); Format$(SUM, "#.###000")
    Next I
End Sub