How to solve this question?

Write an m-file function called lup_decomp.m that decomposes a matrix A into L, U, and P. U is found using Gaussian Elimination with partial pivoting.

To find P and L:

(1) Start with P = I, and L = 0

(2) We set the elements of L as we do in L U decomposition (using the factors calculated from Gaussian Elimination).

(3) Whenever we swap rows during the course of partial pivoting, we also swap the same rows in L and P.

(4) When we are all finished, we set the diagonal elements of L to 1.

Inputs: A The matrix to decompose

Outputs:

L The lower triangular matrix

U The upper triangular matrix

P The permutation matrix

Yes, this is a homework problem. I'm not asking for answer but some tips on how to solve this cause I don't even know where to start.

[dpb]

Well, certainly you must know the first line...and certainly 1). Then one would presume if you've been doing the homework up to now you've already got the routine needed for 2)...