d5r9.txt

来自「常用的数值算法的VB程序」· 文本 代码 · 共 33 行

Private Sub Command1_Click()
    'PROGRAM D5R9
    'Driver for routine PCSHFT
    NVAL = 40
    PIO2 = 1.5707963
    Dim C(40), D(40)
    A = -PIO2
    B = PIO2
    Call CHEBFT(A, B, C(), NVAL)
    Print
    Print Tab(5); "How many terms in Chebyshev evaluation?"
    'Input MVAL , between 6 and 40, MVAL=0 TO END
    MVAL = 20
    If (MVAL <= 0) Or (MVAL > NVAL) Then Exit Sub
    Print Tab(5); MVAL
    Call CHEBPC(C(), D(), MVAL)
    Call PCSHFT(A, B, D(), MVAL)
    'Test shifted polynomial
    Print Tab(5); "    X          Actual      Polynomial"
    For I = -8 To 8 Step 1
        X = I * PIO2 / 10#
        POLY = D(MVAL)
        For J = MVAL - 1 To 1 Step -1
            POLY = POLY * X + D(J)
        Next J
        Print Tab(5); Format$(X, "#0.000000");
        Print Tab(19); Format$(FUNC(X), "#0.000000");
        Print Tab(33); Format$(POLY, "#0.000000")
    Next I
End Sub
Function FUNC(X)
    FUNC = (X ^ 2) * (X ^ 2 - 2#) * Sin(X)
End Function