algorithm - VBA 中的双重求和

Question

我正在尝试在 VBA 中实现以下算法:

请参阅链接:VT-Micro Algorithm

这是我的代码:

s = 7.2
a_inkmhs = 7.2
Total_Fuel = 0
If a_inkmhs >= 0 Then
For i = 0 To 3
    For j = 0 To 3
        Cl = P_coeff(i, j)
        Fuel = Exp(Cl * (s ^ i) * (a_inkmhs ^ j))
     Next j
     Total_Fuel = Total_Fuel + Fuel
Next i
Else
 For i = 0 To 3
    For j = 0 To 3
        ML = N_coeff(i, j)
        Fuel = Exp(ML * (s ^ i) * (a_inkmhs ^ j))
     Next j
     Total_Fuel = Total_Fuel + Fuel
Next i
End If

预期输出: 0.002338176 我越来越 : 3.999006792

问题: 我的实现可能有什么问题。

Answer 1

请注意，您计算的是指数之和，而不是和的指数。此外，更新 Total_Fuel = Total_Fuel + Fuel 应该在内部 for 循环内，否则您将无法正确计算双倍和。正如@VincentG 提到的那样，您的 If 应该测试 a_inkmhs 而不是 a (或者您可以将 a_inkmhs 重命名为 a) 并且在求和期间 a_inkmhs 应该提高到 j 的幂而不是 i ，即 a_inkmhs^j。代码应该是:

s = 7.2
a_inkmhs = 7.2
Total_Fuel = 0
If a_inkmhs >= 0 Then
For i = 0 To 3
    For j = 0 To 3
        Cl = P_coeff(i, j)
        Fuel = Cl * (s ^ i) * (a_inkmhs ^ j)
        Total_Fuel = Total_Fuel + Fuel
     Next j
Next i
Else
 For i = 0 To 3
    For j = 0 To 3
        ML = N_coeff(i, j)
        Fuel = ML * (s ^ i) * (a_inkmhs ^ j)
        Total_Fuel = Total_Fuel + Fuel
     Next j
Next i
End If
Total_Fuel = Exp(Total_Fuel)