How to transpose a matrix without using built-in functions?

How do I write a function (called transposeMat) that returns the transpose of a given 3x3 matrix without using any built-in functions (I cannot use transpose(M), rot90(M), or the transpose operator)? The function will receive an input argument x, which is a 3x3 matrix, and will return one output argument y, which is a 3x3 matrix. Below is a possible sample run I was given.

>> transposeMat ([1 2 3; 1 2 1; 3 5 1])

ans = 1 1 3

2 2 5

3 1 1

Answer 1

[David Hill]

B=[A(1:3);A(4:6);A(7:9)];