Tag Archives: M-file

February 15, 2011, 11:42 am

An M-file to generate easy-to-row-reduce matrices

In my Linear Algebra class we use a lot of MATLAB — including on our timed tests and all throughout our class meetings. I want to stress to students that using professional-grade technological tools is an essential part of learning a subject whose real-life applications closely involve the use of those tools. However, there are a few essential calculations in linear algebra, the understanding of which benefits from doing by hand. One of those calculations is row-reduction. Nobody does this by hand; but doing it by hand is useful for understanding elementary row operations and for getting a feel for the numerical processes that are going on under the hood. And it helps with understanding later concepts, notably that of the LU factorization of a matrix.

I have students take a mastery exam where they have to reduce a 3×5 or 4×6 matrix to reduced echelon form by hand. They are not…

Read More

February 17, 2010, 9:59 pm

And so it begins: Lab #1 in the MATLAB course

The MATLAB course began in earnest on Monday this week with our first full-length lab activity session. This was the second overall meeting, the first one being some organizational stuff and a lengthy fly-through of the main features of MATLAB. What follows is a breakdown of what we did and how it went, which also serves as an invitation for critique and suggestions in the comments.

First, some context. I intend for this course to be heavily hands-on with an emphasis on self-teaching within reasonable bounds. I laid a ground rule in the first class meeting that any question of the form “How do you do ____ in MATLAB?” was going to be met with the responses “What have you found in the MATLAB help documentation? What have you found via a Google search? What have you found out from your lab partner?” I’m not above giving hints to students in the class, but I insist that they exhaust all…

Read More