在excel中用VB对两列数据进行四参数曲线拟合，并输出方程

在 Excel 中使用 VB 语言进行四参数曲线拟合并输出方程，可以使用以下步骤：

1. 在 Excel 中打开“开发人员”选项卡，单击“Visual Basic”按钮打开 Visual Basic 编辑器。

2. 在 Visual Basic 编辑器中，单击“插入”菜单，选择“模块”。这会在编辑器中创建一个新的模块。

3. 在新的模块中，输入以下代码：

Function FourParamFit(x As Range, y As Range) As String

' 定义变量
Dim n As Long, i As Long
Dim sumx As Double, sumy As Double, sumxy As Double, sumxx As Double
Dim sumxxx As Double, sumxxxx As Double, sumyxx As Double
Dim a As Double, b As Double, c As Double, d As Double

' 计算变量的值
n = x.Count
sumx = 0: sumy = 0: sumxy = 0: sumxx = 0
sumxxx = 0: sumxxxx = 0: sumyxx = 0
For i = 1 To n
    sumx = sumx + x(i)
    sumy = sumy + y(i)
    sumxy = sumxy + x(i) * y(i)
    sumxx = sumxx + x(i) * x(i)
    sumxxx = sumxxx + x(i) * x(i) * x(i)
    sumxxxx = sumxxxx + x(i) * x(i) * x(i) * x(i)
    sumyxx = sumyxx + y(i) * x(i) * x(i)
Next i

' 计算四参数曲线拟合的系数
a = (n * sumxy - sumx * sumy) / (n * sumxx - sumx * sumx)
b = (sumy * sumxx - sumx * sumxy) / (n * sumxx - sumx * sumx)
c = (sumxxxx * sumy - sumyxx * sumxxx) / (sumxxxx * sumxx - sumxxx * sumxxx)
d = (sumyxx - a * sumxxx - b * sumxx) / sumxx

' 返回方程
FourParamFit = "y = " & a & "x^3 + " & b & "x^2 + " & c & "x + " & d

End Function

4. 在 Excel