Multiplication of 2 matrix different

Hello I have 2 matrix A=22*3. How to do? And thanks

[Rik]

@hotait hassane: Flagging your question as spam will not remove it. In fact, I'm going to store a copy in this comment in case you want to edit away the text. This is a public forum, in which you can get free help (which you got from John). It might not be the answer you were hoping for, but such is life sometimes. I can't give you any other advice than John did. Did you ask your supervisor/teacher who gave you this as an assignment for clarification? We might be able to help you solve the question that led to this.

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Multiplication of 2 matrix different

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Hello I have 2 matrix A=22*3 B=22*7 need to multiply them to have a matrix C with dimensions 22*3. How to do? And thanks

Answer 1

[John D'Errico]

You should proably read the getting started tutorials, as this is a pretty basic question.

In your early math courses, where they talked about matrix multiplication (if you never took any class like that, then why are you using MATLAB in the first place?) you should have learned how to multiply matrices, and what are the requirements for such a multiplication.

B is 22*7.
A is 22*3.

You cannot multiply those matrices, and have a result that is 22*3.

You could multiply the transpose of B, times A. That would give you a 7*3 matrix. I'm sorry, but those matrices do not conform in such a way to get the result you wish to see, thus nothing gives you a 22x3 result.

So, as I said, the getting started tutorials are a good place to start. But it seems like you need to go back and read some of your notes from one or more of your courses. Or maybe take one?

[Rik]

To be honest, I believe my first courses where I used Matlab was more than half a year before my first course in vector calculus (which was the first point in my study where I learned anything about matrix multiplication). So you can use Matlab without knowledge about matrix multiplication.

Although I must admit this is a strange quirk in the curriculum.