Gradschool on traviscj/blog

things you don't learn in grad school

Mon, 01 Jan 2018 00:00:00 +0000

oncall exists.
the data is never available how you need it.
unit tests matter.
pushing code after 3pm is risky if you’re not willing to work all night. (courtesy Paul Joos)

spring-mass visualization

Wed, 31 Jul 2013 00:00:00 +0000

I’m working on a paper about an algorithm for hotstarting nonlinear program solves; one application of this might be in the realm of nonlinear model predictive control. In these types of models, we first define the physical equations for the system under consideration. They are subject to some control parameters, which are just a mathematical representation of the input we could give the system. We also define an objective–something that we would like to minimize(usually something like time or energy).

Getting really fast at LaTeX

Wed, 10 Apr 2013 00:00:00 +0000

Taking LaTeX notes in real time is one of my favorite useless party tricks. I started developing my techniques during the last year or two of undergraduate work at University of Washington, and was extremely good at it by the end of coursework at Northwestern. There are several keys to taking LaTeX notes in real time:

Know LaTeX.
Shortcut appropriately.
Type keystrokes quickly.
One keystroke re-renders.
Type fewer keystrokes.
Type fewer “strange” keystrokes (backslashes, curly braces, etc)
Re-renders should scroll to your current location in the text.
Extremely rapid debugging of LaTeX expressions.

Before I get started, one other note: I mention TextMate a few places, but in principle there is no reason you couldn’t configure all the same things in Vim, Emacs, or Sublime Text. If I was starting over, I might use Sublime Text instead.

Perturbation Theory Problems with bvp4c

Mon, 22 Oct 2012 00:00:00 +0000

I have been watching Nathan Kutz’ lectures on Coursera. One change he made to the course since I took AMATH 581 at University of Washington was introducing the MATLAB function bvp4c. I immediately realized that this would be nice for solving boundary layer problems that arise in asymptotics.

Following my life philosophy of doing the dumbest thing that could possibly work, I tried implementing Nathan’s code for a single-layer boundary layer problem from Holmes, Chapter 2:

McCormick Interview - Outreach 101 + QUALS

Wed, 13 Jun 2012 00:00:00 +0000

I was interviewed and given a semi-prominent placement in Northwestern’s McCormick Magazine for the outreach work that 2011-2012 NU-IEEE President Curtis Wang and I have put together. Permalink to article. It was a really nice writeup and really great to get to throw out a mention of Joyce Stark!

In other news–I had a crazy couple of weeks due to preparing for (and eventually, taking!) my PhD qualifying examinations. They consist of a panel of three professors questioning me on intricacies of material that I’ve been learning over the last couple of years, namely: Numerical PDE methods, Analytic PDE methods, and optimization. Professor Kath had a particularly interesting question where I derived the heat equation from a minimum-energy problem. The exams went for 95 minutes, followed by a 5 minute deliberation, after which each professor came out with handshakes and congratulations.

spamfunc for optimization in matlab

Mon, 30 Jan 2012 00:00:00 +0000

what spamfunc is

In developing optimization algorithms, one of the most tedious parts is trying different examples, each of which might have its own starting points or upper or lower bounds or other information. The tedium really starts when your algorithm requires first or second order information, which might be tricky to calculate correctly. These bugs can be pernicious, because it might be difficult to differentiate between a bug in your algorithm and a bug in your objective or constraint evaluation. Handily, Northwestern Professor Robert Fourer wrote a language called AMPL, which takes a programming-language specification of objective and constraints and calculates derivatives as needed. The official amplfunc/spamfunc reference is contained in Hooking Your Solver to AMPL, but I’m shooting for a more low-key introduction.

Five Critical Textbooks for (Applied!) Math & Physics Students

Sun, 04 Sep 2011 00:00:00 +0000

In the course of working through my first year at grad school, I’ve come up with five favorites for the basics of an undergrad understanding of the essential topics for applied math and physics. Without ado and in the order I’d take them off my shelf:

Mathematical Methods in the Physical Sciences - ML Boas. This is my favorite, because it contains almost every technique you need, and it has a ton and a half of problems(over 3400). It contains a good review of complex analysis, linear algebra, differential equations, and calculus, but also chapters on special functions, partial differential equations, probability, tensors, and the calculus of variations. – Hidden Gem: Chapter 4, Section 12: Differentiation of Integrals, RP Feynman’s favorite trick.
Calculus - Greenspan. A great reference on calculus.
Complex Variables and Applications - Brown & Churchill: The most readable book on complex analysis I’ve read. Not so hidden gem: Most of the solutions are given right alongside the problem–a great book for self-study. Also the material on conformal mapping and fluid flows.
Linear Algebra And Its Applications - Strang. Nice book on linear algebra theory. – Hidden Gem: Chapter 7, Section 4: Iterative Methods for Ax=b and Gershgorin’s circle theorem.
Elementary Differential Equations and Boundary Value Problems - Boyce & DiPrima. Powerhouse of differential equation knowledge. Strangely, it is the book ESAM recommended, but not the book they use for teaching their undergrads.

I’ve spent probably the most time with Boas’ Mathematical Methods in the Physical Sciences–I’ve worked nearly 1000 problems out of the book to get ready for the preliminary exams my first year. It was completely worthwhile.

Tunes U and Essential Mathematica

Sun, 13 Dec 2009 00:00:00 +0000

In a similar vein to the TED talks in the previous post, I’ve also been watching a lot of lectures from iTunes U lately. Mostly to get ready for preliminary exams, but also for their sheer awesomeness of the teaching and material. I’ve been most surprised how many people haven’t heard of this yet: Nearly everyone seems surprised when they hear about it. Anyways, here’s my list of favorites so far:

Northwestern University

Sun, 19 Apr 2009 00:00:00 +0000

I finally committed to graduate school a few weeks ago. I’ll be headed to Northwestern University in Evanston, IL for the [Engineering Sciences and Applied Mathematics]](http://esam.northwestern.edu) department.

I really enjoyed both the visit at University of North Carolina and Northwestern the week before last. But I think I could like Chicagoland quite a lot, so I guess that’s where I’m headed!

Mission Graduate School -- Success

Wed, 25 Feb 2009 00:00:00 +0000

I’ve officially been accepted to two PhD applied math programs: Northwestern and University of North Carolina. I’ve also been accepted to the Masters of Science program at the University of Washington. Both of the PhD offers came with full fellowship offers(at least for the first year), which basically means that I just need to go and give them the best bang for their buck with my brainpower for five years, and then I’ll have my PhD. Awesome. All three schools are outstanding and have amazing faculty, as best as I can tell.

Graduate School Applications and Microsoft

Mon, 09 Feb 2009 00:00:00 +0000

I finally finished graduate school applications last weekend. I applied to University of Washington, University of North Carolina, Northwestern, University of Colorado, and University of Nevada. It’s a lot of work getting a bunch of applications out like that: I definitely underestimated it. Hopefully my personal statement measured up to the letters of recommendation that people wrote for me.

I also ended up having an interview with Microsoft that week, just to add a bit to the stress there. It actually went fairly well, though I haven’t heard back on the round-two interview yet. They said it would be a while though.

Graduate School Applications

Fri, 02 Jan 2009 00:00:00 +0000

I am finally getting around to starting my graduate school applications.. and overall having a lot of fun with them. The places I’m applying to are:

University of Washington, Seattle
Northwestern, Evanston
University of North Carolina, Chapel Hill
University of Colorado, Boulder I’ve got my UW Seattle application about half done, and just starting the other ones.

The UW has apparently gotten my full GRE scores, because they are now reporting them through the unofficial transcript interface. I don’t quite recall where I sent them already.. I’ll probably get that going soon.

Where I'm At

Sat, 03 Mar 2007 00:00:00 +0000

So it’s almost the end of Winter Quarter 07 at the University of Washington. It’s cold and rainy and lame. Last week I got turned down from the Computer Science program here, which meant I spent the weekend generally freaking out.

In any case, I then remembered that I liked the idea of an ACMS degree. The base of the major consists of the physics series, a Numerical Methods course and a Continuous modeling course from the AMATH department, and discrete models and statistics from the math department.