Private Sub Command1_Click()
    'PROGRAM D12R1
    'Driver for routine FOUR1
    NN = 32
    NN2 = 2 * NN
    Dim DATA(64), DCMP(64)
    Print Tab(5); "h(t)=real-valued even-function"
    Print Tab(5); "H(n)=H(N-n) and real?"
    For I = 1 To 2 * NN - 1 Step 2
        DATA(I) = 1# / (((I - NN - 1#) / NN) ^ 2 + 1#)
        DATA(I + 1) = 0#
    Next I
    ISIGN = 1
    Call FOUR1(DATA(), NN, ISIGN)
    Call PRNTFT(DATA(), NN2)
    Print Tab(5); "h(t)=imagnary-valued even-function"
    Print Tab(5); "H(n)=H(N-n) and imaginary?"
    For I = 1 To 2 * NN - 1 Step 2
        DATA(I + 1) = 1# /(((I - NN - 1#) / NN) ^ 2 + 1#)
        DATA(I) = 0#
    Next I
    ISIGN = 1
    Call FOUR1(DATA(), NN, ISIGN)
    Call PRNTFT(DATA(), NN2)
    Print Tab(5); "h(t)=imagnary-valued even-function"
    Print Tab(5); "H(n)=H(N-n) and imaginary?"
    For I = 1 To 2 * NN - 1 Step 2
        DATA(I) = (I - NN - 1#) / NN /(((I - NN - 1#) / NN) ^ 2 + 1#)
        DATA(I + 1) = 0#
    Next I
    DATA(1) = 0#
    ISIGN = 1
    Call FOUR1(DATA(), NN, ISIGN)
    Call PRNTFT(DATA(), NN2)
    Print Tab(5); "h(t)=imagnary-valued odd-function"
    Print Tab(5); "H(n)=-H(N-n) and real?"
    For I = 1 To 2 * NN - 1 Step 2
        AAA = (I - NN - 1#)
        DATA(I + 1) = AAA / NN / (((I - NN - 1#) / NN) ^ 2 + 1#)
        DATA(I) = 0#
    Next I
    DATA(2) = 0#
    ISIGN = 1
    Call FOUR1(DATA(), NN, ISIGN)
    Call PRNTFT(DATA(), NN2)
    'Transrorm, inverse-transform test
    For I = 1 To 2 * NN - 1 Step 2
        DATA(I) = 1# / ((0.5 * (I - NN - 1) / NN) ^ 2 + 1#)
        DCMP(I) = DATA(I)
        DATA(I + 1) = (0.25 * (I - NN - 1) / NN)
        DATA(I + 1) = DATA(I + 1) * Exp(-(0.5 * (I - NN - 1) / NN) ^ 2)
        DCMP(I + 1) = DATA(I + 1)
    Next I
    ISIGN = 1
    Call FOUR1(DATA(), NN, ISIGN)
    ISIGN = -1
    Call FOUR1(DATA(), NN, ISIGN)
    Print Tab(5); "FORuble Fourier Transform:   Original Data:"
    Print Tab(5); "k     Real h(k)   Imag h(k)    Real h(k)   Imag h(k)"
    For I = 1 To NN Step 2
        J = (I + 1) / 2
        Print Tab(5); Format$(J, "##");
        Print Tab(12); Format$(DCMP(I), "##.#####0");
        Print Tab(25); Format$(DCMP(I + 1), "##.#####0");
        Print Tab(38); Format$(DATA(I) / NN, "##.#####0");
        Print Tab(51); Format$(DATA(I + 1) / NN, "##.#####0")
    Next I
End Sub
Sub PRNTFT(DATA(), NN2)
    Print Tab(5); "n  Real H(n)  Imag H(n)  Real H(N-n)  Imag H(N-n)"
    Print Tab(5); Format$(0, "0");
    Print Tab(12); Format$(DATA(1), "##.#####0");
    Print Tab(25); Format$(DATA(2), "##.#####0");
    Print Tab(38); Format$(DATA(1), "##.#####0");
    Print Tab(51); Format$(DATA(2), "##.#####0")
    For N = 3 To (NN2 / 2) + 1 Step 2
        M = (N - 1) / 2
        MM = NN2 + 2 - N
        Print Tab(5); Format$(M, "##");
        Print Tab(12); Format$(DATA(N), "##.#####0");
        Print Tab(25); Format$(DATA(N + 1), "##.#####0");
        Print Tab(38); Format$(DATA(MM), "##.#####0");
        Print Tab(51); Format$(DATA(MM + 1), "##.#####0")
    Next N
End Sub