Calculate Matrix Inverse without the MINVERSE function in excel

**shirleyxiao** · 10-06-2013, 04:41 PM

I have to write a VBA function that will calculate the inverse of an arbitrary 2X2 or 3X3 matrix, involving the adjoint of the matrix. The function should flag any unsuitable matrices that are not 2X2 or 3X3 and should stop. I can't use the MINVERSE function in Excel.

**protonLeah** · 10-06-2013, 05:04 PM

Making use of CELLS(Row,Column) in a loop to calculate the determinant. Use a loop to divide the A_ij's by D.

**shirleyxiao** · 10-06-2013, 05:58 PM

I'm really new to VBA, so I don't know how to do that. It would great if anyone can help me get started with some codes.

**MrShorty** · 10-07-2013, 11:17 AM

In many ways, I find it interesting that someone "really new to VBA" has been assigned what I would consider a more advanced problem like this. As protonleah says, this is going to involve using the cells method and different loops to perform the numerous calculations that go into inverting a matrix. If you are unfamiliar with those concepts, then I would suggest you first come to understand those concepts before tackling the matrix inversion algorithm. A couple of references: http://msdn.microsoft.com/en-us/libr...ice.11%29.aspx
http://msdn.microsoft.com/en-us/libr...ice.11%29.aspx

This might be a useful reference. http://www.ccodechamp.com/c-program-...rse-of-matrix/ His example code is in C, but he also describes the algorithm he is using in building the code (including the adjoint or adjugate). Once you understand enough VBA, this should be useful in putting the code together.

One last thought. As someone who is "really new to VBA," it would help us help you if you could pose specific questions that help us see what you do know and what you don't know so we can best help you learn the concepts that you will need to put this together.