pendag.txt

来自「用VB实现线性方程组的求解。包括：高斯消元法」· 文本 代码 · 共 27 行

Sub PENDAG(A(), B(), C(), D(), E(), R(), U(), N)
    Dim W(100), BETA(100), ALPHA(100), CG(100), H(100)
    W(1) = C(1)
    BETA(1) = 0#
    BETA(2) = D(1) / W(1)
    ALPHA(1) = 0#
    ALPHA(2) = E(1) / W(1)
    ALPHA(N) = 0#
    ALPHA(N + 1) = 0#
    For K = 2 To N
        CG(K) = B(K) - A(K) * BETA(K - 1)
        W(K) = C(K) - A(K) * ALPHA(K - 1) - CG(K) * BETA(K)
        If W(K) = 0# Then Print "    W(K)=0.0 in PENDAG"
        BETA(K + 1) = (D(K) - CG(K) * ALPHA(K)) / W(K)
        ALPHA(K + 1) = E(K) / W(K)
    Next K
        H(1) = 0#
        H(2) = R(1) / W(1)
    For K = 2 To N
        H(K + 1) = (R(K) - A(K) * H(K - 1) - CG(K) * H(K)) / W(K)
    Next K
        U(N) = H(N + 1)
        U(N - 1) = H(N) - BETA(N) * U(N)
    For K = N - 2 To 1 Step -1
        U(K) = H(K + 1) - BETA(K + 1) * U(K + 1) - ALPHA(K + 1) * U(K + 2)
    Next K
End Sub