vb嵌套循环算不出来，SOS

显示全部楼层 · 2010-5-11 11:19:05

Dim dfe As Double
sum = 0
dfe = 0
Do
Tf = -20
e = 0.1
For i = 1 To 25
K(i) = pc(i) / P * Exp(5.373 * (1 + w(i)) * (1 - tc(i) / Tf))

Do

fe = fe + y(i) * (K(i) - 1) / ((K(i) - 1) * e + 1)

dfe = dfe - (K(i) - 1) ^ 2 * y(i) / (1 + e * (K(i) - 1)) ^ 2

If fe < 0.0001 Then

Exit Do

Else

e = e0 - fe / dfe

If Abs(e - e0) < 0.0001 Then Exit Do

e0 = e

End If

Loop
X(i) = y(i) / ((K(i) - 1) * e0 + 1)
c(i) = K(i) * X(i)
sum = sum + c(i)
Next i
If Abs(sum - 1) < 0.0001 Then Exit Do
Loop
前面的数组定义省略咯。我点击运行后老是程序未响应。是不是循环太多卡住啦？请大侠们帮帮忙，救我于水火之中。

千问 · 2010-5-11 11:19:05

两层循环不多，关键是你退出循环的条件是不是一定能满足。如内层的退出条件是fe < 0.0001 和Abs(e - e0) < 0.0001 是否一定会满足，外层的退出条件是Abs(sum - 1) < 0.0001是否一定会满足，要注意检查。另你程序中Tf = -20，e = 0.1放在了外层的循环内，不知是你的本意吗？