A view from above
This view shows different types of crime in San Francisco viewed directly from above. The sun is shining from the east, as it would during sunrise.

I love how some of the features in these maps are pretty consistent across all the crime types, like the mountain ridge along Mission St., and how some of the features only crop up in one or two of the maps. The most unique map by far is the one for prostitution (more on that further down).

An alternate view
Here’s the same data but from a different angle, which helps show some of the differences.

UPDATE: Whoops, I screwed up originally and had a duplicate image. The original graphic showed the same map for Vandalism and Assault (both were the Vandalism map). This updated graphic has the correct map for Assault.

Many of the maps have peaks in the Tenderloin, which is that high area sort of in the north-east center area of the city. Some are extremely concentrated (narcotics) and some are far more spread out (vehicle theft).

My favorite map is the one for prostitution (maybe “favorite” is the wrong choice of words there). Nearly all the arrests for prostitution in San Francisco occur along what I’m calling the “Mission Mountain Ridge”, which runs up Mission St between 24th and 16th.

EDIT: I’ve been corrected. Upon closer inspection the prostitution arrests are peaking on Shotwell St. at the intersections of 19th and 17th. I’m sure the number of colorful euphemisms you can come up with that include the words “shot” and “well” are endless.

I love the way the mountain range casts a shadow over much of the city. There’s also a second peak in the Tenderloin (which I’m dubbing Mt. Loin).

Drug crimes are also interesting to look at, since so much of the drug activity in San Francisco is centered in a few distinct areas. We can see Mt. Loin rising high above all the other small peaks. The second highest peak is the 16th St. BART peak.

There are other consistent features in these maps, in addition to Mt. Loin and the Mission Range. There’s a valley that separates the peaks in the Mission and the peaks in the Tenderloin, which is where the freeway runs (Valley 101). You’ll also notice a division in many of the maps that separates the southeast corner. That’s the Hunter’s Point Riverbed (aka the 280 freeway).

Disclaimer
These maps were generated from real data, but please don’t take them as being accurate. The data was aggregated geographically and artistically rendered. This is meant more as an art piece than an informative visualization.

As I was flying back home into San Francisco airport I was watching the city lights out the window and got struck by a bit of inspiration. I find cities beautiful, from the graffiti to the neon signs to the line of headlights on the highway. A city viewed from above at night is captivating. I wanted to try to recreate that same look, but by visualizing data (in one sense you can say that the real view of a city from above is already a visualization of population data).

I started searching for images of cities at night, and found these amazing images from NASA. All those images were taken from a space shuttle orbiting the earth. These images tell you a lot about the city, the layout, urban density, planning (or lack thereof). I wanted to take other meaningful data and create similar images.

All the visualizations below have been created with SpatialKey. However, this is some experimental work I’ve been playing with to generate the “night light” images, so it’s not released (and might not ever be). Basically this is a peak behind some of the R&D work I do for fun (yes, for a dataviz dork like me making fake “cities at night” images is my idea of fun).

Crime in San Francisco
This image is all crime in San Francisco for a 3-month period. You can see some of the same features that you can see in the NASA space image, such as Golgen Gate Park and the Presidio (the area on the north-west edge of the city). All in all it’s interesting how similar the crime image looks compared to the NASA image. Downtown is the brightest spot in both images, which means that it’s literally the brightest area of the city (the most streetlights), and also has the most crime.

And here are breakdowns for a few different crime types. Notice how different the distributions are. Narcotics crimes are heavily clustered and can be found downtown (in the Tenderloin), in the Mission (near the 16th St BART station), and along Haight Street near Golden Gate Park. Whereas vehicle theft is scattered fairly evenly throughout the city.

Narcotics

Theft

Vehicle Theft

Burglary

Graffiti Reports in San Francisco and New York
Both San Francisco and New York publish their 311 data, which is when citizens call for city services. One category of 311 calls is to report graffiti. Graffiti is interesting in that it often follows specific city streets. When we look at the graffiti data for both cities we see specific streets that have far more graffiti than others. I love these images (particularly the one of SF) because they really look like a view of street lights from a plane.

Trees planted in San Francisco
Another one of my favorites of this set is data for all the trees that the city of San Francisco has planted since 1990 (all this SF data is available at datasf.org). You can see the heavy planting along Market St (which cuts diagonally through downtown), as well as along streets like Sunset Blvd (the street running north/south on the western side of the city).

Street lights (or SF as a giant lite-brite)
One final image of San Francisco we have is the locations of every street light in the city. I liked this image because it reminded me of playing with a Lite-Brite when I was a kid. It almost makes city planning feel light a grown-up version of playing with little plastic lights.

Check out the video below and read the full article on the SpatialKey blog.

Read the whole article on the SpatialKey blog to see how we put this together and learn more about the SFPD’s “Operation Safe Schools.” You can also watch the full resolution video on YouTube

As a brief disclaimer in case I slur any words near the end: I was in Denver for a short trip and we squeezed in a time to meet with Jon and James right before I had to head to the airport to fly home. The only problem was that we had to meet at about 10am in the morning. And since the show is called Drunk on Software we obviously had to be drinking. So by the time I got on my flight I was probably 6 beers down

A big thanks to Jon and James for making the time to have us over (that’s the living room of Jon’s house). And thanks for the beer guys!

Here’s an excerpt from the article talking about SpatialKey:

Today, the officers are using the new BI tools to perform geographic profiling of crimes and analysis of police data “in seconds,” he says. Before, it could take days for the department’s single crime analyst to fulfill a report request. An added bonus is that experienced police officers with extensive street experience are now able to apply their firsthand knowledge to crime analysis.

“You have practitioners asking the what-if questions, which has changed the way we police,” Greiner says.

And here’s the cover of this month’s print edition of the magazine:

That’s our heatmap! Yeah!

Quick links
Before I explain what SpatialKey is I wanted to give a few quick links because I know a lot of you are going to have your ADD act up before you read the rest of the post.

• SpatialKey Gallery – lists a few dataset/template pairs that we think tell great stories. Read the descriptions of the datasets and then launch the app to play with the data yourself.
• 
  San Antonio Prostitution hotspots

  San Antonio Prostitution Crimes – This link will jump you straight into exploring the prostitution crimes in San Antonio from Jan 2006 – July 2007. Check out how clearly the heatmap points out the corners that are the hotspots in the city.

• Growth of Walmart – This link will load the Walmart dataset into a playback template that lets you click play and watch Walmart take over America.

Beyond points on a map

Overwhelmed with markers

We’ve been seeing the same tired approach to web-based mapping for years now. Everyone throws markers on a map. You want to track crime? Throw a bunch of markers on a map. Little pin markers work fine if you’re showing a few data points. Want to see the location of Starbucks within a 3 block radius of your house? Use markers. But what if you want to see the total sales of all Starbucks worldwide? Or all crimes for the past 10 years? For the whole country?

SpatialKey uses some of the most advanced visualization renderings for geospatial data that have ever been seen on the web. The focus here is on aggregate renderings: heatmaps, thematic grids, graduated circles. 1,000 markers all piled on top of each other doesn’t help anyone. What you want to see is density or sum total value. SpatialKey focuses on rendering aggregate data in meaningful ways. We can show you a heatmap of the entire country and let you visualize any number of data fields. You want to see the heatmap represent total sales of all stores in the region? No problem. You want to see average house price over the past 10 years? We can do that.

Heat Map	Heat Grid

We haven’t seen innovative technology in this industry since Google let you drag the map. (I actually vividly remember that moment when I first dragged a Google map and my mouth started to water). It’s time to move beyond points on a map.

Your data doesn’t have limits
Try adding 10,000 data points to a Google Map. I dare you. What happens? If you’re using the “My Maps” feature of Google Maps, you’re limited to only show 200 points at a time, then you have to page through your data. And to top it all off you’re limited to a whopping total of 1,000 data points in the entire data set. So you get to page through 5 pages of data and only see 1/10th of your total data set anyway. If you create your own application with the Google Maps AJAX API you’re going to have serious performance problems when you get up into a few hundred markers. We think that’s ridiculous.

SpatialKey breaks through the limits of previous mapping technology in two ways. First, we’re simply faster. Flash can process and render data far faster than JavaScript. We can render 10,000 data points in a matter of milliseconds. You simply can’t do that with any JavaScript API out there. Second, we’re smarter. We aggregate data to produce heatmaps instead of just trying to overlay markers one on top of the other. Fundamentally, a massive dataset is an information visualization problem, not a technical one. You need better renderings to convey massive amounts of data, and that’s what SpatialKey delivers.

This is just the beginning
This is a technology preview. That basically means we’re showing you some cool stuff, but we’ve got way more up our sleeve. We’re looking for feedback on what we’ve got, and we’re hoping to get you excited about what we’ll be rolling out. We’ll be releasing new versions of SpatialKey Personal that will let you easily import your own data (if you’ve got an Excel file with addresses you can drop it right in). We’re also going to be releasing SpatialKey Enterprise, which lets you load a data set of any size (millions and millions of points). And then we’ve got a third product that we’re launching called SpatialKey Law Enforcement Dashboard, which is an enterprise version of SpatialKey specifically targeted toward police departments (includes special law enforcement reporting templates). And in the meantime we’ll be rolling out some more example datasets for you to play with, so keep an eye on the SpatialKey blog.

So go check out the SpatialKey Gallery and play with some data. We’re looking for feedback during this phase, so if you have any suggestions or (god forbid!) you run across bugs, please let us know by emailing feedback.

Method
I just got my very first Blackberry (the Curve), which has built-in GPS. The first thing I wanted to figure out (after getting gmail on the phone) was how to store position reports automatically. There are a few pieces of software that sort of do this, although some applications store the position logs locally on the SD memory card, which you then download to your computer. There are also some subscription-based services catered more toward enterprise-level fleet management that do way more than I need (TeleNav Track, Accutracking) . The SD card approach is no good for me. I’m lazy, and I know there’s no way I’m ever going to transfer the position log from my phone to my computer. The subscription service is a bit more realistic (Accutracking even has a REST API), but I’m not excited about having to keep a subscription paid and active and rely on someone else for my reports. The only real workable solution was to find an application that automatically sent the position information to a web server, and ideally to my own webserver so I can have full control over the data.

Enter Mologogo. Mologogo is a free application and service for GPS-enabled phones that does exactly what I wanted. It runs automatically every few minutes (mine’s set to run every 5 minutes) and sends your position report to the Mologogo online service, which keeps track of your points. That’s halfway to what I needed. The icing on the cake is that the Mologogo application has an awesome feature that lets you set your own URL that the service will also send the position report to. Bingo. This lets you save your position reports in your own database to do whatever you want. I grabbed some of the sample PHP code from the Mologogo wiki and installed it on my personal web server. After configuring the Mologogo Blackberry app I was getting position reports logged in my database.

Why?
This is not about showing where I am in real-time. This is not about “life-streaming” or “life casting” or whatever the current buzzwords are for letting strangers watch every moment of your life. I do not plan on showing my current location on my blog, or letting people see exactly where I am as I’m there. I’m not going to do that for a few reasons, and privacy is one of them I guess, although I’m not really freaked out about the idea of having my current location be public knowledge. The main reason is that I think that stuff is boring as hell. I watched Justin.tv for all of about 5 minutes, and the entire draw of that kind of lifecasting is the hope that the person you’re watching is going to do something stupid, which usually happens specifically because they’re living to entertain their audience. Other people (in fact most of the people who use Mologogo I assume) like the concept of simply letting people see their latest position reports. But why? I don’t find the idea of viewing where some random guy (or even a good friend) is at the current instant compelling. I suppose if all my friends automatically told me where they were that could be kind of cool and helpful for meeting up. But whatever, that’s semi-useful and still boring.

This is about analyzing historical data. It’s about the visualization of years, the visualization of decades. It’s about being able to see the geographic context of my life. I probably won’t do anything with this data for a year or two. It only becomes truly valuable after extended periods of time.

To try to think about how much data we’re talking about here’s the approximate math:

1 report every 5 minutes = 12 reports an hour = 288 reports a day = 105,120 reports a year = 1 million reports a decade

So theoretically let’s say I can somehow figure out how to actually do this constantly until I’m 80 years old. That would be about 5 and a half million records that would catalog my movement around the world for most of my life. That amount of data is already easy to store online. I can store millions of records like this in an inexpensive hosted database, ideally duplicated in multiple locations for redundancy. So the challenge isn’t about how to store the data, it’s about what to do with it, and that’s where it starts to get fun.

Visualizing the geospatial context of life
The important things in your life have a geographic context. Moving to a new city, changing jobs (even if that just means a slightly different commute), traveling on vacation, etc etc. The geographic movements of your life are directly tied to meaningful experiences. Being able to visualize those movements is like having a picture of a certain time of your life.

I wish I had the data for the past few years. It would have shown me in college, then moving to San Francisco. I could have seen the daily commute I did for a few years, and then the change to working from home. Imagine a heatmap on a map showing where I spend my time. While I was commuting to work you would have been able to make out the route of the train I took every day, and the amount of time I spent simply getting to and from the office. Compare that with my current lifestyle, which now involves either working from my home or my girlfriend’s place, which would also show a kind of “commute”, but this one is very different. This commute represent a shift in where I spend my time, and even beyond showing a change in my work life, it also signifies the strengthening of our romantic relationship. This is a visual representation of a very meaningful part of my life. Being able to visually see this movement is a way to quantify important changes. I imagine creating some amazing looking visual images of this type of data and hanging them on the wall. A single image would represent so much.

Challenges
The biggest challenge is going to be keeping new data updated and old data accessible as technology changes. In another year or two I will have a different mobile device, at which point I’ll have to figure out how to use the new device to keep the position reports updated. In another ten years who knows what kind of device I might be carrying around in my pocket. There’s just no way to predict that kind of stuff. So every few years I’ll have to figure out how to keep my reports updated using new technology. I’ll also have to adapt to changes in how I store that data. Storing it in a database works well now, but inevitably I’ll have to migrate that data from one database to another, or even move from a relational database to some other form of storage. This means I’ve got to either stay geeky enough to know how to implement this stuff for the rest of my life, or I’ve got to figure out a solution that literally requires no changes for the next few decades (I don’t think this is at all possible).

There are also some more immediate challenges. I don’t know how to keep my positions logged as I travel internationally yet. Even as I’m in the US I’ve got to ensure that the logging software is always running on my phone. My phone needs to be on at all times for the reports to come in. Ideally I’m going to try to write my own custom software to do exactly what I want, just so I know how it works under the hood in case something breaks or I upgrade devices. I’m not stoked about the fact that I’m tied to software written by someone else. I’ve also obviously got to keep the webserver that receives the reports up and running at all times. I’ll probably try to move to more of a database in the cloud approach using Amazon SimpleDB and EC2 so I can rely on Amazon instead of my current web host (I imagine I’ll always be relying on some company to handle this kind of stuff).

I’m excited about the possibilities for using this data in a few years, I just hope I can keep the position feed coming in.