hunt.txt

用VB实现多种数值插值方法。包括：接格朗日

Sub HUNT(XX(), N, X, JLO%)
    ASCND = XX(N) > XX(1)
    If JLO% <= 0 Or JLO% > N Then
        JLO% = 0
        LHI% = N + 1
        GoTo 3
    End If
    INC% = 1
    If X >= XX(JLO%) Eqv ASCND Then
1       LHI% = JLO% + INC%
        If LHI% > N Then
            LHI% = N + 1
        ElseIf X >= XX(LHI%) Eqv ASCND Then
            JLO% = LHI%
            INC% = INC% + INC%
            GoTo 1
        End If
    Else
        LHI% = JLO%
2       JLO% = LHI% - INC%
        If JLO% < 1 Then
            JLO% = 0
        ElseIf X < XX(JLO%) Eqv ASCND Then
            LHI% = JLO%
            INC% = INC% + INC%
            GoTo 2
        End If
    End If
3   If LHI% - JLO% = 1 Then
        Exit Sub
    End If
    JM% = (LHI% + JLO%) / 2
    If X > XX(JM%) Eqv ASCND Then
        JLO% = JM%
    Else
        LHI% = JM%
    End If
    GoTo 3
End Sub