Colleagues, I wrote VBA code for function of Gauss elimination (in attached files). But I can't launch this function in Excel. I can't find it by her name in line for function's input.
Could you please help me with checking my code (in attached file)?
I would like to suggest you to use MATLAB, that may be more sufficient and convenient for your task.
Unfortunately, end-users can't use Matlab. Only Excel, due to possibility of automation of estimate through macroses.
Hi Kirill,
what does Next J, I do? As far as I understand your code, the I-loop never closes. That's probably your mistake. Also, you used Next instead of Next J in another part. How do you plug in the matrix and the vector into your function? I guess you use ranges in the spread sheet?
I have no clue how to make your function to work. Here is the code though, that might work?!
Option Base 1
Option Explicit
Function GaussElim(coeff_matrix, const_vector)
Dim AugMatrix() As Double, ResultVector() As Double
Dim NormFactor As Double
Dim temp As Double, term As Double
Dim I As Integer, J As Integer, K As Integer
Dim C As Integer, R As Integer
Dim N As Integer
N = coeff_matrix.Rows.Count
ReDim AugMatrix(N, N + 1), ResultVector(N)
' Create augmented matrix with dimensions Nx(N+1)
For I = 1 To N
For J = 1 To N
AugMatrix(I, J) = coeff_matrix(I, J)
Next J
For J = 1 To N
AugMatrix(J, N + 1) = const_vector(J)
Next J
For K = 1 To N
' Normalize each row, from column K to right
' If normalization factor zero, swap rows
NormFactor = AugMatrix(K, K)
If NormFactor = 0 Then
For J = 1 To N + 1
temp = AugMatrix(K, J)
AugMatrix(K, J) = AugMatrix(K + 1, J)
AugMatrix(K + 1, J) = temp
Next J
NormFactor = AugMatrix(K, K)
End If
For C = K To N + 1
AugMatrix(K, C) = AugMatrix(K, C) / NormFactor
Next C
' Eliminate
For R = K + 1 To N
ElimFactor = AugMatrix(R, K)
For C = K To N + 1
AugMatrix(R, C) = AugMatrix(R, C) - AugMatrix(K, C) * ElimFactor
Next C
Next R
Next K
' Calcucate and return the coefficients.
' Selected range can be either horizontal or vertical.
For K = N To 1 Step -1
ResultVector(K) = AugMatrix(K, N + 1)
term = 0
For C = N To K + 1 Step -1
term = term + AugMatrix(K, C) * ResultVector(C)
Next C
ResultVector(K) = AugMatrix(K, N + 1) - term
Next K
If Range(Application.Caller.Address).Rows.Count > 1 Then
GaussElim = Application.Transpose(ResultVector)
Else
GaussElim = ResultVector
End If
Next I
End Function
Hello, Martin. Sorry for the delay
1. Insert new module in VBA's programming interface. Then you need to input code from me.
2. After completed action from point above, you can launch created function through her specfic name (" GaussElim").
I solved this problem with launch by myself.
Unfortunately, I can't get all values from the solution by my code to cell in Excel. And I don't know how to solve this issue.
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