Wednesday, May 21, 2008

About a year ago, I worked with Jeff Lindsay for a couple months. He worked on the demo for the project I'm still working on, and he set me up with a source code repository, wiki and ticket system: all an integrated part of his devjavu.com work. Since I hate maintaining these development services but must have them, it's a perfect solution for me. I recommend it.

BTW, today Jeff showed me how to give anonymous permissions to the source code repository, so I did. Here's what I'm working on :)

Thursday, May 15, 2008

I've been writing import tools (not quite screen scraping, but close). Today I used those import tools to grab a bunch of CDC data on causes of death. This can get a little depressing at times. Sometimes I notice a large number of people died of something I didn't even realize was a cause of death. Look at the skew to age in death attributed directly to dementia:

Other times, it's nice to note that hardly anybody dies of something (e.g. cannabis usage, such low numbers I didn't bother importing). Here's deaths due to all mental and behavioural disorders from use of psychoactive substance (and nearly all of them are alcohol):

Sunday, May 11, 2008

I took Zack Arias' OneLight Workshop on Friday. It was, on the whole, awesome, as many others have reported, with the personal exception explained below.

We spent several hours reviewing the science and the analysis of light, shutter speed and aperture. Being an engineer, I can pretty much memorize this level of technical stuff when it's presented as clearly as Zack does: words in my eyes (slides), words in my ears (him speaking), a couple diagrams, quite a few examples and definite humour. So far so good.

The next part of the workshop I was totally unprepared for. This was the part where Zack set up a lighting situation and a model, explained the setup, and then let everybody in turn use their own camera (but his light) to shoot the model. I was a nervous wreck and confused and embarrassed and disfunctional.

Half of my problem -- and both halves were my problem, not the workshop's -- was that I didn't know my camera well enough. I thought I knew how to shoot in manual mode, but while nervously fiddling to get that to actually work, I screwed up several other settings on my camera. It took me another hour after that to recover proper focus, because I could not relax and look and see what was wrong. I've used other fully manual cameras before, and I've shot with the Rebel in aperture priority or shutter priority mode, but I needed to know *this* camera well enough to be able to focus on other things besides the camera's button's and dials and screen. Ouch.

The other half of my problem was sudden incapacitating social awkwardness. I was completely bashful about working with live, volunteer models I'd never met before. I was intimidated by going before and after professional photographers who knew their cameras and who were joking comfortably with the models. I was embarrassed at wasting everybody's time, the models and the other photographers waiting to use the same light setup. I was too wrapped up in my own awkwardness to ask the models to turn their head, or move closer to the light, or up or down. Stupid, huh? They were lovely, friendly, patient models but I was completely flustered. I think I babbled incoherent apologies at them at the end of each "shoot".

As this part of the workshop continued into our third and fourth light setups, or about two hours after quietly flipping out, I started pulling things together. Several people definitely tried to be helpful and were in fact helpful (thanks Tara and of course Zack) but I was at that point where I was too self-conscious to be very effective at accepting help. I've seen other people in that position but haven't experienced it myself recently. It's a humbling reminder for when I'm in "helper" role of saying "Oh, just do it this way". I got my focus straightened out. I started adjusting my aperture in the right direction instead of consistently doing it in the wrong direction. I got to that moment where I decided to try to alter a shot by taking down the light on the background compared to the model. I worked it through: I remembered I had to increase the shutter speed to pick up less ambient light, while maintaining an aperture that picked up the flash on the subject at the same brightness. The result, while in no way a good photo -- I mean, not at all -- was at least the product of an intention that I formulated to make use of what I'd learned.

It all went uphill from there. I started to be able to make a plan and imagine a look and adjust what part of the background was in the photos and how much light it had. I really didn't take a lot of good photos but increasingly I was able to make changes that I thought of. I took notes of what I was doing to cement the principles.

At the end, I finally got comfortable photographing one of the photographers. This was in the part of the workshop where we split into groups and set up our own lighting. Tara setup a shoot-through umbrella near a wood fence, and Bärbel was the fellow photographer who sat for my shooting, as I sat through hers:

Bärbel in our 7th light setup

I was now comfortable enough to ask Bärbel to move away from the fence, to give more separation between the light on her and the light on the fence, thus more control at dialing one up and one down. I was comfortable enough to move the umbrella/flash stand closer to her to her. I was still trying to be quick and didn't take a zillion shots with different facial expressions or different compositions, but since I was there to learn the lighting part that was OK. And I got this shot, and I was happy.

Thanks to our hosts who provided excellent food and a location, and the models and fellow photographers and Zack. I was too dorky to act normally but if you happen to stumble on this I want you to know I enjoyed myself and learned a lot.

Monday, May 05, 2008

I'm getting into geographical distributions and shapefiles now for the health data accessibility project. Ekr and Cullen got the basic R and maptools extension commands working for me. I tweaked it a bit and now have thumbnails and detail views (shown here, deaths attributed to HIV in white males):



  



One thing I've learned about freely-available shapefiles is that they have a lot of crap in them. Crap is, of course, in the eye of the beholder. In my case, I want the shapes of the regions only, and not the population, households, whites, blacks, males, females, density, age distributions, divorced, married, never married, single-parent household, household units, vacancies, mobile homes, farms, crop acres and more counts/rates, for every region.

I can probably get a shapefile editor and remove that stuff but it will only slim down the files slightly. Even bigger than all that data are the latitude and longitude of every vertex required to draw a state outline. Think coastline and all those islands in Alaska, Puget Sound, etc. Since my map sizes are limited anyway, I wonder:
  • how many vertexes I could afford to lose without losing any
    resolution in the larger size, and how I could find a shapefile appropriate for that
  • how much smaller the resulting shapefiles would be
  • whether that would be any faster anyway
Performance is a problem right now! I can trivially do caching of drawn maps but it's at the point of slowing development down at times I do not want to cache.

Thursday, May 01, 2008

The code review I got from Grant last weekend was really great, but I'm back to programming solo. Luckily, one of the nice things about code reviews is that when you explain something, you are likely to see problems with it before the person you're explaining to even finishes parsing your tech-tech-tech. And you don't even need the other person to make this work if you're disciplined enough to read code aloud all by your lonesome. (I can read code to the cat at home, but maybe I need a teddy bear at work.)

So here's how I read some code to myself yesterday:


Okay, first step here is we get a list of graphs to draw, it's a generator.
We go through each graph figuring out which datafiles we need to load so we
only load them once.

This we know is working so far because of print statements, showing two
datafiles in this case.

Now the next step, we're going through the generator again,... oh.


Yeah, you can't use a generator twice in Python and I knew it, but I didn't remember it until I heard myself speaking out loud. What's up with that?

Blog Archive

Creative Commons License
This work is licensed under a Creative Commons Attribution 3.0 Unported License.