vba多元一次方程组矩阵解法

vba多元一次方程组矩阵解法
在VBA中，可以使用矩阵解法来求解多元一次方程组。

下面是一个使用矩阵解法的VBA函数示例：
```vba
Function SolveEquations(matrix As Variant, constants As Variant) As Variant
Dim n As Integer
n = UBound(matrix, 1)
Dim augmentedMatrix() As Variant
ReDim augmentedMatrix(1 To n, 1 To n + 1)
' 构建增广矩阵
Dim i As Integer, j As Integer
For i = 1 To n
For j = 1 To n
augmentedMatrix(i, j) = matrix(i, j)
Next j
augmentedMatrix(i, n + 1) = constants(i)
Next i
' 高斯消元法求解方程组
Dim k As Integer, pivot As Double, factor As Double
For k = 1 To n
pivot = augmentedMatrix(k, k)
For i = k To n + 1
augmentedMatrix(k, i) = augmentedMatrix(k, i) / pivot
Next i
For i = 1 To n
If i <> k Then
factor = augmentedMatrix(i, k)
For j = k To n + 1
augmentedMatrix(i, j) = augmentedMatrix(i, j) - factor * augmentedMatrix(k, j)
Next j
End If
Next i
Next k
' 返回解向量
Dim solution() As Variant
ReDim solution(1 To n)
For i = 1 To n
solution(i) = augmentedMatrix(i, n + 1)
Next i
SolveEquations = solution
End Function
```
使用示例：
```vba
Sub Example()
Dim matrix(1 To 2, 1 To 2) As Variant
matrix(1, 1) = 1
matrix(1, 2) = 2
matrix(2, 1) = 3
matrix(2, 2) = 4
Dim constants(1 To 2) As Variant
constants(1) = 5
constants(2) = 6
Dim solution() As Variant
solution = SolveEquations(matrix, constants)
MsgBox "x = " & solution(1) & ", y = " & solution(2)
End Sub
```
这个示例中，给定一个2x2的系数矩阵和一个长度为2的常数向量，利用上述函数可以解得方程组的解向量。

最后将解向量展示出来。