Private Sub Command1_Click()
    'PROGRAM D11R6
    'Driver for routine POWELL
    NP = 3
    NDIM = NP
    FTOL = 0.000001
    Dim P(3), XI(3, 3)
    For I = 1 To NP
        For J = 1 To NP
            XI(I, J) = 0#
        Next J
    Next I
    XI(1, 1) = 1#
    XI(2, 2) = 1#
    XI(3, 3) = 1#
    P(1) = 1.5: P(2) = 1.5: P(3) = 2.5
    Call POWELL(P(), XI(), NDIM, NP, FTOL, ITER, FRET)
    Print
    Print Tab(5); "Iterations:  "; Format$(ITER, "##")
    Print
    Print Tab(5); "Minimum found at: "
    Print
    For I = 1 To NP
        Print Tab(5 + (I - 1) * 12); Format$(P(I), "#.#####0");
    Next I
    Print Tab(5)
    Print Tab(5); "Minimum function value =  "; Format$(FRET, ".#####0")
    Print
    Print Tab(5); "True minimum of function is at: 1.0   2.0   3.0"
End Sub
Function FUNC(X)
    FUNC = F1DIM(X)
End Function
Function FUNC2(X(), N)
    AAA = (X(1) - 1#) ^ 2 + (X(2) - 2#) ^ 2 + (X(3) - 3#) ^ 2
    FUNC2 = 0.5 - BESSJ0(AAA)
End Function