Just an update on the gas mileage efficiency I’ve been getting with my 2007 Honda Civic (automatic transmission). The orange line represents the average, which is currently hovering just above 30MPG. The EPA rating was 25/36 so I’m doing pretty well still.
It does look like the efficiency may have dropped a little bit starting around autumn 2011. But it’s hard to say for sure since the gasoline formulations change regularly what with the summer/winter mixes and inconsistent ethanol levels.
We went down to southern California for most of the week on a short vacation. We drove down on Sunday and met up with Josh (of Project Runway fame) for dinner. On Monday we met up with him again to go to the Aquarium of the Pacific in Long Beach.
Traffic in the Los Angeles area is notoriously bad, but what makes it even more fun is when they hold a Grand Prix event on the blocks that surround the place you’re trying to get to. The Aquarium had been closed over the weekend for the race, but reopened on Monday. However, they were just starting to take down all of the fencing, barriers, stands, etc. from the race. So roads were randomly blocked off and everything our GPS unit wanted us to do was simply not possible. We finally wandered into a member of the event staff at yet another intersection where our only allowed movement was a U-turn. They were able to tell us how to get to the aquarium.
Heather thought it was pretty great.
For somewhat unknown reasons, the aquarium also has a lorikeet exhibit you can walk through. You can buy a little cup of nectar to feed the birds. This wasn’t any of us, just some random other person feeding this bird.
Jess finds the jellyfish to be mesmerizing.
Here’s Heather playing in a touch pool:
Josh meets up with a sea turtle:
And this is Jess’ other favorite thing at aquariums, sea dragons:
And this is where we part ways.
Heather got up this morning and just couldn’t hold in her dance energy, so we put some music on for her and let her go.
It’s the best 60 seconds you’ll spend this week, I promise.
I posted about this on Google+ a while back, but I’ve updated the site and it’s now much cleaner. I still have a few features I’d like to add in the future, but they don’t really impact the site’s purpose.
Anyway, I present AutomatonSimulator.com:
In Computer Science we study simple automatons called finite-state machines. They are equivalent to various useful language concepts. For example, Deterministic Finite Automata (DFA) can be used to process any Regular Language (i.e., regular expressions, which are infinitely useful). And Push-Down Automata (PDA) can process any Context-Free Grammars.
In the CS course I TA’d for as a student, CS 252, a chunk of the course is devoted to working with these concepts. This usually means developing a working automaton design based on some desired language recognition. For example, make a machine that will accept strings that alternate between “A” and “B”. Or, make a machine that will accept strings that have the same number of “A”s as “B”s.
They’re usually quite meaningless in and of themselves, but the point is to develop the skills necessary to understand how programming languages are created and why, as well as to hone the ability to logically analyze problems and build logically consistent solutions.
Well, we had to do all this work by hand. Drawing out machines, tracing through their execution, finding bugs, and making sure they did what they were supposed to without doing things they weren’t supposed to.
As the TA I had to grade a lot of these messily drawn machines that often didn’t work. It was tiring. So to aid my grading I wrote a simple simulator in Python for each machine type. Then I’d encode each student’s machine into my simulator, run a bunch of tests and figure out from there whether it worked and, if not, how badly it was wrong.
AutomatonSimulator.com is a fully functional tool to visually create and test these types of machines. I took my Python simulators, rewrote them in Javascript, and built a lovely UI around them.
You can save/load machines from your browser’s local storage. Or you can copy/paste machine descriptions to share with other people. A small set of examples is included on the site. You can debug a machine by stepping through an input and you can bulk test a large set of strings with a single button press.
I had fun creating the site and hopefully CS students will find it useful in developing their understanding of finite-state machines.
Something I’d like to do in the future is to build a simple game around the site. It wouldn’t be very involved, but it would challenge the user to build a machine for a certain language and help them make the connections between these machines and regular expressions. We’ll see if I get around to it someday.
About half our lawn died last summer while no one was living in the house. So I decided I’d see if I could revive it. I put down some seed and fertilizer a couple of weeks ago and have been watering it faithfully. And now you can finally see the new grass sprouting up! Another few weeks and the lawn should be looking great (aside from the various weeds that I still need to dig out).
