d5r6.txt

VB常用数值算法集 内含有解线性代数方程组

Private Sub Command1_Click()
    'PROGRAM D5R6
    'Driver for routine CHINT
    NVAL = 40
    PIO2 = 1.5707963
    Dim C(40), CINT1(40)
    A = -PIO2
    B = PIO2
    Call CHEBFT(A, B, C(), NVAL)
    'Test integral
    Print
    Print Tab(5); "How many terms in Chebyshev evaluation?"
    'Input MVAL , between 6 and 40, MVAL=0 TO END
    MVAL = 20
    Print Tab(5); MVAL
    If (MVAL <= 0) Or (MVAL > NVAL) Then Exit Sub
    Call CHINT(A, B, C(), CINT1(), MVAL)
    Print Tab(5); "    X         Actual     Cheby. Integ."
    For I = -8 To 8 Step 1
        X = I * PIO2 / 10#
        Print Tab(5); Format$(X, "##.###000");
        Print Tab(18); Format$(FINT(X) - FINT(-PIO2), "##.###000");
        AAA = CHEBEV(A, B, CINT1(), MVAL, X)
        Print Tab(32); Format$(AAA, "##.###000")
    Next I
End Sub
Function FUNC(X)
    FUNC = (X ^ 2) * (X ^ 2 - 2#) * Sin(X)
End Function
Function FINT(X)
    'Integral of FUNC
    AAA = 4# * X * ((X ^ 2) - 7#) * Sin(X)
    FINT = AAA - ((X ^ 4) - 14# * (X ^ 2) + 28#) * Cos(X)
End Function