Question

我正在使用VBA集成到Excel中。我在工作表上的组织表中有许多集成过程所需的变量，这些变量将根据需要进行更改。我已经编写了以下代码来完成此任务，并已成功调试了上述代码，从而可以正确编译。

Dim dIdt As Range
Dim Isnp As Range
Dim Tau As Range

Dim A As Range
Dim B As Range
Dim C As Range
Dim D As Range


Function Iscr(t)
Set dIdt = Worksheets("Sheet1").Range("F11").Value
Set Isnp = Worksheets("Sheet1").Range("F14").Value
Set Tau = Worksheets("Sheet1").Range("F13").Value
Iscr = (dIdt * t) + (Isnp * (Exp((-t) / Tau)))
End Function

Function Econd1A(t)
Set A = Worksheets("Sheet1").Range("B17").Value
Set B = Worksheets("Sheet1").Range("B18").Value
Set C = Worksheets("Sheet1").Range("B19").Value
Set D = Worksheets("Sheet1").Range("B20").Value
Econd1A = A + (B * (Log(Iscr(t)))) + (C * (Iscr(t))) + (D * (Iscr(t) ^ (1 / 2)) * Iscr(t))
End Function

Function Econd1(x0, t1, t2)

'define range of integral
int_range = t2 - t1

'discretize the integral into n slices dt wide
n = 1000
dt = int_range / n

'initialize variables
ta = t1
tb = ta + dt
Econd1 = x0

'calculate areas using trapezoidal rule

'sum area under curve of each slice
For j = 1 To n
Econd1 = Econd1 + (tb - ta) * (Econd1A(ta) + Econd1A(tb)) / 2
ta = tb
tb = ta + dt
Next

End Function

由于错误似乎与VBA无关，我现在在调试方面无所适从。

该单元格的预期输出为.0127，但它给出的是#VALUE！错误。

Answer 1

Function Iscr(ByVal t As Double) As Double
    Dim dIdt As Double, Isnp As Double, Tau As Double
        dIdt = Worksheets("Sheet1").Range("F11").Value
        Isnp = Worksheets("Sheet1").Range("F14").Value
        Tau = Worksheets("Sheet1").Range("F13").Value
        Iscr = (dIdt * t) + (Isnp * (Exp((-t) / Tau)))
End Function

Function Econd1A(ByVal t As Double) As Double
    Dim A As Double, B As Double, C As Double, D As Double
        A = Worksheets("Sheet1").Range("B17").Value
        B = Worksheets("Sheet1").Range("B18").Value
        C = Worksheets("Sheet1").Range("B19").Value
        D = Worksheets("Sheet1").Range("B20").Value
        Econd1A = A + (B * (Log(Iscr(t)))) + (C * (Iscr(t))) + (D * (Iscr(t) ^ (1 / 2)) * Iscr(t))
End Function

Function Econd1(ByVal x0 As Double, ByVal t1 As Double, ByVal t2 As Double) As Double
Dim int_range As Integer
    int_range = t2 - t1
    n = 1000
    dt = int_range / n
    ta = t1
    tb = ta + dt
    Econd1 = x0
        For j = 1 To n
            sEcond1 = sEcond1 + (tb - ta) * (Econd1A(ta) + Econd1A(tb)) / 2
            ta = tb
            tb = ta + dt
        Next j
Econd1 = sEcond1
End Function

Answer 2

Excel的计算引擎将用户定义的函数（UDF-从工作表单元格调用的自定义函数）中引发的所有错误包装起来，并产生#VALUE单元格错误，而不是像损坏的VBA代码那样正常地爆炸。无需进行任何错误处理，调试UDF会很“有趣”。

实施错误处理：

Public Function MyUDF(args)
    On Error GoTo ErrHandler
    '...code...
    Exit Function
ErrHandler:
    Debug.Print Err.Description
    Stop ' halts execution
    Resume 'jumps back to the error-raising statement
End Function

在VBE中使立即窗格可见（Ctrl + G），然后计算一个正在调用UDF的工作表，其中包含可能覆盖所有边缘情况的多个可能的输入-特别注意值会导致溢出和除以零错误。

在Stop关键字处停止执行时，按F8键运行Resume语句，这将使您直接进入引起错误的语句-从此处可以检查所有涉及的变量，然后逐步浏览功能以验证数学执行过程-您还可以将“当前指令”黄线移回到已经执行的语句上，以重新运行它-只是将黄色箭头拖到函数中所需的位置，或右键单击指令并选择“设置下一条语句”。

一旦您知道该函数按预期工作，就可以删除该错误处理/调试代码，并且可以接受给定无效参数的#VALUE错误。

＃值！包含成功编译的VBA函数的单元格上的错误

2 个答案: