Inverse and multiplication of Matrices In VBA

[adashiu]

1) I have declared:

Mtrx(20,20) as Integer, where i have a Matrix

1 2 3
1 2 3

How can I do an inverse of this matrix using only VBA commands?


2) I have :
Mtrx(20,20) as Integer, for example :

3 1
2 0

and Mtrx1(20,20) as Integer :
1 2 0
0 1 1

How to multiply these matrices using only VBA ?

Thanks a lot for your help

[shg]

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[adashiu]

Ummm... I think you used an excel worksheet to make it, but i cant use it actually. Is it possible?

[shg]

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[adashiu]

It does not work here... Where should i put my arrays Mtrx and Mtrx1, which are declared as Arrays(20,20) of Integers? sorry for problems...

[shg]

You're going to have to explain more clearly what you are trying to do.

[adashiu]

Look :
Im doing a VBA program, which will multiply and do an inverse of a matrix.
I have created a form, similar to this:

form1.jpg

But a user can define number of rows and columns.
I store all data entered by user to TextBoxes in previously delcared array Mtrx(20,20) as Integer.

I have the same for where user put data for another matrix Mtrx1.

So i have Matrix filled with a data of user.

For example :
User wants to multiply a Matrix 2x2 with a Matrix 2x3. He puts data to Mtrx and Mtrx1.

And now if i have this data inside my Mtrx and Mtrx1. I want to multiply those 2 matrices. I hope You understand now

[shg]

So load the data from the text boxes into the two matrices, and multiply as in the example I posted, changing the variable names to agree with yours:

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You must use a Variant to receive the result.

[adashiu]

I did so but it does not work... Run-Time Error '1004'.

I have created a sample file with 2 matrices. Could you apply your code to my sample file? And make multiplied matrix to show on Excel Sheet? It would really help me. Sorry for troubles. I hope i would be able to help you in future.

SampleMatrix.xls

Greets, Adam

[shg]

Run this in a scratch workbook:

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Remarks:

1. Arrays have a default base of 0 in each dimension, unless you use Option Base 1 (not recommended). You should declare array extents explicitly.

2. If you're going to vary the size of arrays, they must be dynamic, as illustrated above. Help covers this.