这个倒序和蝶形算法vb程序如何运行？
Sub 倒序(X_() As Double)Dim n As Integer, i As Long, j As Long, mn As Long, lh As Long, t As Double, k As Long
'位序倒置
n = UBound(X_) '求数组大小，其值必须是2的幂
lh = n / 2
j = n / 2
For i = 1 To n - 2
If i < j Then '倒序
t = X_(j)
X_(j) = X_(i)
X_(i) = t
End If
Debug.Print i, j
k = lh '下面是向右进位算法
Do
If k > j Then Exit Do '高位是1吗
j = j - k '是的，高位置0
k = k / 2 '准备次高位的权
Loop Until k = 0 '次高位的权若非0，则检查新的次高位
j = j + k '非则若最高位是0，则置1
Next
End Sub
蝶形算法代码
Sub 蝶形算法(xr() As Double)
Dim l As Long, le As Long, le1 As Long, n As Long, r As Long, p As Long, q As Long, m As Byte
Dim wr As Double, w1 As Double, wlr As Double, wl1 As Double, tr As Double, t1 As Double
Dim pi As Double, t As Double
Dim xi()
n = UBound(xr) '求数组大小，其值必须是2的幂
m = 0
l = 2
pi = 3.14159265358979
Do
l = l + l
m = m + 1
Loop Until l > n
n = l / 2
ReDim xi(n - 1)
l = 1
Do
le = 2 ^ l
le1 = le / 2
wr = 1
wi = 0
w1r = Cos(t)
w1i = -Sin(t)
r = 0
Do
p = r
Do
q = p + le1
tr = xr(q) * wr - xi(q) * wi
ti = xr(q) * wi + xi(q) * wr
xr(q) = xr(p) - tr
xi(q) = xi(p) - ti
xr(p) = xr(p) + tr
xi(p) = xi(p) + ti
p = p + le
Loop Until p > n - 1
wr = wr * w1r - wi * w1i
wi = wr * w1i - wi * w1r
r = r + 1
Loop Until r > le1 - 1
l = l + 1
Loop Until l > m
For i = 0 To n - 1 '仅输出模
xr(i) = Sqr(xr(i) ^ 2 + xi(i) ^ 2)
Next
End Sub
检验的时候可以这样：
Sub 检验()
Dim y(63) As Double
For i = 0 To 64
y(i) = Sin(2 * 3.1415926 * i / 16)
Next
倒序 y()
蝶形算法 y()
'现在结果在y()中
End Sub
