### Highlights from LU Factorization by Doolittle's method

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# LU Factorization by Doolittle's method

03 Jun 2005 (Updated )

LU factorization of a square matrix.

File Information
Description

This program factorize(decompose)the square matrix of any size into a product of a Lower-triangular matrix (L) and an Upper-triangular matrix (U). All the elements of the main diagonal in the L matrix are ones, (Doolittle's method).

This factorization is very helpfull in solving different mathematical problems and problems in linear control systems.

MATLAB release MATLAB 7 (R14)
21 Jul 2013

I want to algorithm for this program.

10 Aug 2011

thx Dr.yaseen you are creative I hope many successes to you

26 Feb 2010

No comments, messes workspace, C style programming. This file should be removed from the FEX.

31 Aug 2008

Thanks, Excellent.

16 May 2008
26 Jan 2008

It was usefull for me.

16 Nov 2007

See my comments below - I didn't select a rating in my last review.

03 Aug 2007

Nice

02 Jun 2007

The file doesn't have any comments, so it isn't useful as an educational tool. The lutx.m function in Cleve Moler's NCM toolbox (http://www.mathworks.com/moler/ncmfilelist.html) is much better code (simpler, easier to read, and well commented). Plus, lutx.m comes with extensive documentation in Cleve's book which you can download for free. The file here has none of that.

Cleve even has an LU GUI in which you can watch the LU factorization, with pivoting, occur before your very eyes.

So for educational use, there are far far better alternatives.

Of course, for dense or sparse LU factorization this function (if it were converted into a function) would not be used in production code since it's far far slower
than the MATLAB built-in LU.

So why is it here? What purpose could it serve? Why does the File Exchange have a plethora of Gaussian Elimination variants such as this one?

I would kindly suggest that this file be withdrawn.

27 Apr 2007

very good

12 Feb 2007

This is an excellent program to explain the LU decomposition.

11 Nov 2006

i need this method to finish my thesis about dispatching

14 Apr 2006

It seems written for visual basic, it doesn't use the Matrix Algebra MatLAB offers at all.

21 Jan 2006

Why use a script that does an LU factorization in a completely unvectorized fashion? Especially when there is already a far faster implementation of an LU in matlab itself? Beware, this clears your workspace, then makes you type in the matrix. Its just the author's homework assignment.

18 Jan 2006
05 Dec 2005

Not a function. Clears the base workspace without warning! Poorly duplicates what the function LU does in MATLAB.

06 Nov 2005
08 Jun 2005
06 Jun 2005
06 Jun 2005
06 Jun 2005

Good, as showing the basics of decomposition

06 Jun 2005

Good For implenting Doolittle's method (the elements of the main diagonal are ones).

06 Jun 2005

1) This is a script file, not a function.
2) Why use this function over the builtin MATLAB function LU?
3) Many For Loops in the script are not needed, e.g., you can start L with L=eye(m); rather than with a For Loop that does the same thing.
4) Does your code implement pivoting?
5) Nice homework solution for a beginning numerical methods class.