💾 Archived View for thorjhanson.com › blog › 20190216-my-life-is-now-signals.gmi captured on 2022-06-03 at 22:48:23. Gemini links have been rewritten to link to archived content

-=-=-=-=-=-=-

My Life is Now Signals

2/16/2019

This week started off with a Signals and Systems test Monday at 10am. Signals and Systems is, as I've mentioned before, an incredibly demanding class. The test was very difficult, and afterward, it was homework as usual. I spend more time each week working on Signals homework than I do sleeping. Having finished Chapter 1, we have now moved on to Chapter 2's material: discrete time. We will be performing the same calculations and transformations we did in Chapter 1 (which focused on continuous time), but will now be learning how to modify those concepts for use in discrete time. Discrete time is different from how "normal" math is considered in that it focuses on a function's value at *discrete* points throughout time, rather than a smooth output. Using some code in Matlab (or a similar program, like GNU Octave), a nice demonstration of this concept can be had:

GNU Octave

t = [-10:.1:10]';
x = t.*sin(t);
subplot(2,1,1); plot(t,x); grid on;
xlabel("t");ylabel("x(t)");title("Continuous Time x(t) vs. t");
t = [-10:1:10]';
x = t.*sin(t);
subplot(2,1,2); stem(t,x); grid on;
xlabel("t");ylabel("x(t)");title("Discrete Time x(t) vs. t");

Continuous vs. Discrete time plot demonstration [IMG]

Our homework this week has mostly involved plotting many, many such plots, and understanding the nuance and motivation behind them. One of the applications of discrete time compared to continuous time is when programming computers to perform tasks. Computers cannot continuously measure input or produce output - rather, they work in terms of individual measurements over time. Thus, discrete time techniques can be directly applied to programming a computer for signal processing purposes.

In hall government, we're putting together our next event: FAT5. Usually, FAT (Forever Alone Together) is an ironic Valentine's day event held the Friday closest to Valentine's day, but due to the long weekend, we decided to move the event one week later. Hence, this year's FAT will be held on February 22nd. We've got all our purchasing orders in for food, and made adverts. The adverts will be distributed later tonite, and we anticipate having good attendance.

All this has kept me *much* too busy to work on my Aquaponics. Whenever the parts get ordered, soldering together the controller boxes will be the next step. I enjoy soldering (and don't have a lot of reasons to normally do so), so I quite look forward to this. Once the boxes are soldered, we'll have to modify our PIC microcontroller's code to work on both systems at once, at least until we can set up a more permanent solution.

This week, I also spent a good amount of time working on modernizing the design of my website. With a bit of a layout adjustment and some new colors, I'll next be cleaning it up to submit it to my English teacher as my e-portfolio (due Tuesday!). Preparation for this has also meant adding some more sections to my website, which I'm hoping will make it easier for people to navigate in the future.

Well, that's all for this week. Hope you enjoyed!