Tuesday, February 10, 2009

Temporal heat chart

A few weeks ago, I updated an animated graphic that demonstrates how time effects violent crime in Lincoln. The thought struck me that a temporal heat chart would be another valuable way of looking at these data. I’ve blogged about the technique before, using this method for examining the day-and-hour patterns of traffic crashes. It's a table of values with days of the week in the columns, and hours of the day in the rows. I was suspecting that the temporal clustering of violent crimes would be dramatic. Here’s the result (click to enlarge):


10 comments:

Anonymous said...

I guess walking my dogs Tuesday morning around 5 a.m. isn't a bad idea.

Anonymous said...

Did you try running this data, but leave out the summer months when LPS isn't in regular session? I'll bet that the M-F 3pm slot would "orange up" even more. The simmering concentration of teens and older adolescents in that time slot probably can't be helped, but perhaps if they moved PE to the end of the day, every day M-F, it would sweat some of that aggression of the hormonally-charged little angels before they turned them loose on the city. Wear them out, like playing tennis ball fetch with a dog till it runs out of excess energy.

By the way, do they even do mandatory PE any more, or are a lot of the kids too...overfed to engage in that sort of activity these days?

Buck said...

Most of it would seem to make sense, but I'm curious about the 3 pm anomaly...especially on Wednesday. 'Hump Day' blues???

Tom Casady said...

Buck-

Anonymous 9:00 has it--the 1500 hour weekday slots represent school dismissal time.

Anonymous said...

Chief,
Interesting data.
Another interesting data set to do, family relationships of perpetrators of crime. For instance when I worked the visiting room at the Pen it always amazed me that many of the visitors that came in were related. On Holidays like Thanksgiving or Christmas it seemed like a family reunion in the visiting room.


Gun Nut

Anonymous said...

If we extend bar closing hours until 2am, that orange 2-3am box on Sat & Sun will also be dark red, I think it's fair to predict, while the 3-4am boxes on those same days will turn orange, etc etc etc.

Buck said...

Makes sense...there's definitely a difference between weekdays and weekends in that time slot. The surprising thing is that, according to the graphs, these are violent crimes...are these mostly after-school fights?

Anonymous said...

So apparently -40 below zero relay does keep the “Rift Raft” out, or down!

Tom Casady said...

Buck-

A few after-school fights, but generally, it's just the natural byproduct of releasing 35,000 cooped-up kids with a lot of energy. The timeline on youth crime follows this pattern, whether violent or not.

Patrick said...

Tom-

I've been using the Temporal Heat chart here in Tallahassee for a few months now. It has been a great eye-opener for both the Police and Fire Commands by synthesizing a lot of data down into an easy-to-interpret snapshot.

It has provided new focus for anlayzing our stafffing needs and response times for both departments.

Glad to see it used out in Lincoln, too. :-)