Temperature histogram

In commemoration of the coldest dive I have ever done in a wetsuit, this is a histogram of the water temperatures I have encountered throughout my 160+ dives. Red is for warm water dives (i.e. in a 3mm wetsuit or shorty) and blue is for cold water dives (7mm suit and hood).

At 5ºC, yesterday's dive was a full 3ºC below my previous low (~8ºC at Friday Harbor).

Graphs of a blog of graphs

It's about time this happened, because there was no way I could let these pretty graphs just sit there. Blogger records visitor stats for the blogs it hosts and graphs them. So there are graphs of this blog's visitor traffic. Fig. 1 is a graph of visitor operating systems.

Fig. 1. Visitor operating systems for this blog

Compare that with the OS composition of another more high-traffic Blogger-hosted blog with stats I can access: the TA-run Brown ecology class blog (Fig. 2). Brown is rather maccy in general, but this is a really big difference!!

Fig. 2. Visitor operating systems for Brown ecology class blog

Finally, a general comparison is in order. As I did before when comparing my class diversity over time, this is basically a H' index. I wonder what Shannon et al. would think of my using their index to quantify diversity in ridiculous things, but it's the most familiar measure of diversity to me and here it is (Fig. 3).

Fig. 3. Diversity of this blog vs. the ecology blog

Of course, my real point in posting all these graphs is this idea: if I blog the graphs of the blog and then graph the blog of the graphs of the blog etc. etc. IT WOULD GO ON FOREVER!!!

Next time: web browser diversity!


As a side note: There is obviously some non-independence going on here (e.g. repeat visitors, of which I am sure there are many many many). But this is Blogger's fault and not mine and I am not making any statistical inferences here, so I'm going to pretend all is fine.

Operation retrieve dive gear

Success. Did not get lost or stuck waiting for the next 2.5-hourly bus!

Not the most efficient, but I am still really thankful for public transport. And now my gear is ready to help me freeze while running transects in Nahant this week.

Also: I never knew Providence had a 'Nahant Street' but apparently it does. It is a tiny little street off Charles Street. I passed it on the bus today.

Why "earth hour" annoys me

Because I see no reason to sit in the dark for an hour (other than making yourself feel all fuzzy inside) when there are a million other things you could do to cut energy use more effectively (and without cutting productivity). Like turning off the lights when you're not using them, and not running the hot water when you're not even touching the water, and not taking hour-long hot showers (I am especially bothered by people wasting water because it's like a 2 in 1 'water and energy' going down the drain).


* My room is lit by 2 x 36W fluorescent bulbs in a standing lamp.
** Taking an average shower flow rate of 2.5 gal/min, numbers from here. Note that this is calculated assuming 100% efficiency of the water heater, which is an impossibility, so any realistic value would be higher than what is graphed.

Off meal plan

This is a graph idea that came out of the inevitably frequent conversations with people on my hall and other 'off meal plan' upperclassmen about how ridiculously expensive the college meal plan is. I think it comes out to something like $9 a meal, but a number like that is not that easy to compare to the less well-defined manage-your-own-food-budget. I generally think of meal plan as 'a lot' more expensive than off meal plan but have no clear conception of what 'a lot' is. I decided it would be easier to visualise if I graphed it.

I was pretty surprised at how much 'a lot' really was. My initial idea was to stack things up on my 'off meal plan' bar until it equaled the meal plan bar but I pretty much ran out of 'large expense' things to stack, with over $200 to go.

The graph isn't meant to convey an expenditure switch because none of the other expenses actually 'came out' of meal plan money - Benthics $$ came out of a Brown travel grant and TA stipend, NEAS from the stipend and a research assistant job, dive gear came out of a summer research fellowship, etc. - it's just a visual comparison of magnitude.

Other (qualitative) benefits of not paying the college to make food for you:
1. flexibility
2. feeling like a real person
3. not being utterly lost and helpless when the dining halls close (spring break week, ha.)

Okay I am off to make lunch and work my butt off so I can spend the second half of next spring break freezing in Nahant water and looking for algae.

In and out

I've been scrambling to catch up with everything ever since I got back from the Benthic Ecology Meeting five days ago so I haven't had the time to mess around with data and graphs. But now it's spring break, and even though I have a to-do list as long as my arm, there's some time to play around with excel.

Like most conferences that aren't tiny, Benthics has concurrent sessions (4 of them) and they were close enough that it was very easy to switch from one session to another between talks. Each session had 5-10 talks, so 4-9 potential switches in total. Here is a graph of how much switching we all did (as a proportion of how many possible switches there were):

FYI, we are almost but not 'significantly different' from each other (p~0.09). Though I bet if I just ran a paired test between me and Jason we'd be different. I think I just want to believe that I am significantly different from smelly Jason :)

And below is another graph of switches (again, proportion of total possible), this time by session. Yes, there was one session in which I switched rooms at every possible time, though I think it was mostly moving back and forth between two of the rooms.


Also, 2 great graph ideas that may never see the light of ordinate and abscissa:

1. I wanted to graph our individual paths and movements between sessions, but we moved around and crossed between rooms so much that the graph is just a crazy mess of lines which fails to convey the point. Even the above graph (switching by section) is a little but crazy and falls on the very limit of what I consider worth graphing.

2. If I could figure out which combination of talks each person at Benthics attended, I could use some kind of ordination technique (I'm not sure exactly which would be most suitable) to characterise each person relative to everyone else based on that. Then people who cluster together would probably have similar interests and should talk to each other => awesome way to network, right? But it's kind of lame to do this when I only have data for 4 people. Maybe if I go to Benthics again next year I will try and do this...

Networking at Benthics

(estimated in approximate number of hours spent)

I think we are all terrible at networking.

From the Benthics Meeting...

Out of 22.5 hours, this is the breakdown:

So ridiculously tired. But so worth it. The conference starts for real tomorrow!

Also: Mobile, AL is a pretty little city.

Friend accumulation

I've been working like crazy over the weekend to get everything done before the Benthic Ecology Meeting that starts tomorrow, and I think it's been pretty successful because now I'm sitting here with 4 hours to go before my train leaves and I have nothing pressing to do.

So: in addition to my dive log, guess what is an awesome source of data? Facebook. All the friends I have and all the friends I forgot I had. I decided to graph my Facebook friends against when I first met them. Interestingly but unsurprisingly, there are obvious jumps corresponding to starting at new schools in Primary 4, Secondary 1 and JC. I pretty much lost touch with anyone I went to school with before P4. (The curve starts above zero to account for family members who are older than me.)

Obviously this is a limited dataset because plenty of people aren't on Facebook. I also clean out my friendslist once in a while, so the people graphed are the people I care at least somewhat about. Current total: 273.

On the subject of social networks, my research advisor told me to make the best of this conference and do some networking!!! I think my idea of networking is hanging around networked-people that I know...then when other networked-people come to talk to them, they have to talk to me too to be polite.

Benthics in 24 hours!! :)

Modelling change

So I've been been thinking about math and mathematical models quite a bit lately, partly because they've been showing up in many places this semester.

When I was 8, this was my idea of a model...except that back then I don't think the textbooks were in colour. We drew little bar models all the time. Everyone's models were always straighter and neater than mine, and some kids would bring their colour pencils and colour them in for no good reason at all. Drawing models was the way to solve every math problem and it was awesome until your older neighbour/friend/cousin taught you algebra. Then they became the most ridiculous, tedious things in existence because your teacher wouldn't let you stop using them.

Apparently now they're all the rage among homeschooling parents in the US (and possibly in Utah too?). I guess my messy little primary school self didn't appreciate them enough because I hated having to draw so many straight lines.


Now (10+ years later) models look like this, and there are lots of them everywhere :)
I realised I have actually not had a math class in something like 3.5 years, even though I've used it extensively in some of my classes. I might take an applied math class or two before I graduate...

A venn diagram

So am I the "evil TA" ?

I actually don't think I've been to any of my TAs' office hours before. But then I don't really go to review sessions and organised study groups either. I'm a study-hermit.

Also, I just got my first TA-paycheck :)

Turnover times

Turnover times in my life.

Fig. 1. Bar graph of turnover times

It takes longer for a manuscript to get (nicely and helpfully) rejected than it takes a dog to make lots and lots of puppies.

Fig. 2. Puppies

Research diving vs. 'fun diving' (Part 3)

So this is pretty interesting...
(again, p-value from a two-sample t-test in STATA)

I wonder how much 'real-world' significance this has and how much of the difference is actually due to different regions/dive conditions, since both unadjusted air consumption rates and depth-adjusted 'surface air consumption' (SAC) rates* appear to be lower in warm water (with some variation). I think this one will have to sit on the shelf for a while...more data to come late Spring and Summer when I start getting in the water again.

* and here is the graph of SAC rates by temperature, data from the overall Fall 2009-Summer 2010 year that was used for the graphs of original unadjusted and adjusted SAC rates.

A hypothesis

We talked about density dependence in a tree, masting in another tree and the link between environmental and population synchrony in soil mites. Today was a slow day...

Becoming educated

So taking biochemistry makes me think of my life in RJC, and (somewhat) recently people have been posting links to a couple of blog posts on "growing up in the 90's in Singapore" which unsurprisingly included many references to primary school. Which got me thinking, counting and graphing. This one graph pretty much summarises the last 15 years of my life. Really. I am still a little awed by that fact.

Here are a couple of graphs on the diversity (or 'well-roundedness' which is a term I never really understood because it just made me think of kids in the TAF club) of my education over time. The top graph is a simple count of the number of subject areas (language, math, sciences, social sciences, humanities) each year while the bottom is weighted by the evenness of class composition - basically like a Shannon-Wiener diversity index...BUT FOR CLASSES.


So it looks like I was most diverse around Sec 3 and 4...and least diverse during my 3 seas year. This is what graduate programs do, kids. Expect a downward trend when I start grad school in a couple of years.

Research diving vs. 'fun diving' (Part 2)

Obviously this is because I work in shallow old New England.

The p-value is from a two-sample t-test run in STATA.

Biochemistry flashback

Every time I sit in my biochemistry lecture this semester I have flashbacks of learning some of the same stuff in the lecture theatre and the "Raffles Rooms" at RJC...something like 4 years ago (!!!). So while going over the lecture slides for the first exam I started keeping a count of 'old material' I learnt in JC1 and JC2 (= US grade 11-12) and 'new material', measured in numbers of content-bearing slides. Then, of course, I graphed it.
So...yeah. At least for the first third of the class, there is not that much new stuff. Plenty of re-learning things I forgot, and plenty of re-discovering that molecular-level things are awesome. So, yay for Singapore and the MOE's grand plan to push students into molecular biology and bio-tech-y things? I think that in the 3+ years since I took my A-levels, I've grown to appreciate the value of the strong background in molecular bio and genetics I got out of MOE's syllabus...at the same time, their attempt to push me in that direction obviously didn't work, and I'm glad it didn't :)


(This post is rightfully dedicated to Dr. Adrian Loo, who pretty much taught me everything in the blue part of the pie, answered all my questions on evolutionary biology and ecology, and enjoys getting students stuck in the mud...)

Histograms!!!

Okay, so it must be that none of my previous instructors have been cool enough to exploit the FULL RANGE OF DESCRIPTIVE STATISTICAL TOOLS on MyCourses because I have never seen this little function before. It is seriously awesome.

Behold the BIOL 28 grade histogram!!!

You can toggle the width of the bins (I think the allowed range is from 3 -65 bins). Below is the largest number of bins for which the interval labels are still readable (after this they kind of smoosh together and you just get vertical lines). I won't say how long I spent toggling them back and forth...
So...apart from being awesome by scanning and grading every single exam (of 255) the same day they were taken, the biochemistry instructors win because they have histograms I can play with.