d9r4.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 40 行

Private Sub Command1_Click()
    'PROGRAM D9R4
    'Driver for routine SVDFIT
    NPT = 100
    SPREAD = 0.02
    NPOL = 5
    Dim X(100), Y(100), SIG(100), A(5), CVM(5, 5)
    Dim U(100, 5), V(5, 5), W(5)
    'Polynomial fit
    IDUM& = -911
    MP = NPT
    NP = NPOL
    For I = 1 To NPT
        X(I) = 0.02 * I
        Y(I) = 1# + X(I) * (2# + X(I) * (3# + X(I) * (4# + X(I) * 5#)))
        Y(I) = Y(I) + SPREAD * GASDEV(IDUM&)
        SIG(I) = SPREAD
    Next I
    Call SVDFIT(X(), Y(), SIG(), NPT, A(), NPOL, U(), V(), W(), MP, NP, CHISQ, "FPOLY")
    Call SVDVAR(V(), NPOL, NP, W(), CVM(), NPOL)
    Print
    Print Tab(5); "Polynomial fit"
    Print
    For I = 1 To NPOL
          Print Tab(5); Format$(A(I), "#.##0000"), " +-",
          Print Format$(Sqr(CVM(I, I)), ".#####0")
    Next I
    Print
    Print Tab(5); "Chi-squared  "; Format$(CHISQ, "###.####00")
    Call SVDFIT(X(), Y(), SIG(), NPT, A(), NPOL, U(), V(), W(), MP, NP, CHISQ, "FLEG")
    Call SVDVAR(V(), NPOL, NP, W(), CVM(), NPOL)
    Print
    Print Tab(5); "Legendre polynomial fit"
    For I = 1 To NPOL
        Print Tab(5); Format$(A(I), "#.##0000"), " +-",
        Print Format$(Sqr(CVM(I, I)), ".#####0")
    Next I
    Print
    Print Tab(5); "Chi-squared  "; Format$(CHISQ, "###.####00")
End Sub