midsqu.txt

来自「VB常用数值算法集 内含有解线性代数方程组」· 文本 代码 · 共 25 行

Sub MIDSQU(AA, BB, S, N)
    B = Sqr(BB - AA)
    A = 0#
    If N = 1 Then
        S = (B - A) * SQU(0.5 * (A + B), BB)
        it = 1
    Else
        it = 3 ^ (N - 2)
        TNM = it
        DEL = (B - A) / (3# * TNM)
        DDEL = DEL + DEL
        X = A + 0.5 * DEL
        Sum = 0#
        For J = 1 To it
            Sum = Sum + SQU(X, BB)
            X = X + DDEL
            Sum = Sum + SQU(X, BB)
            X = X + DEL
        Next J
        S = (S + (B - A) * Sum / TNM) / 3#
    End If
End Sub
Function SQU(X, BB)
    SQU = 2 * X * FUNC(BB - X ^ 2)
End Function