You need to divide crime counts by population density. Otherwise you're just plotting population density.
this is not a map of population density it’s pretty clear just the SRO strip/TL and then the two mission bart stations
Show HN: Play with an interactive heatmap of SF crime (and other cities)
11–20 of 137 posts
Re: Show HN: Play with an interactive heatmap of SF crime (and other cities)
#12The TL is high-crime and the Mission bart stations have crime. Not exactly shocking to anyone who has lived here
Re: Show HN: Play with an interactive heatmap of SF crime (and other cities)
#13You need to divide crime counts by population density. Otherwise you're just plotting population density.
Is it actually true that crime in an area increases proportionally with population? Why would it?
Extremely high density but near zero crime would be inside a large office building.
Re: Show HN: Play with an interactive heatmap of SF crime (and other cities)
#14You need to divide crime counts by population density. Otherwise you're just plotting population density.
It's an important truth that walking a mile in a high population density area puts you at a higher crime risk than walking a mile in a medium or low population density area.
Re: Show HN: Play with an interactive heatmap of SF crime (and other cities)
#15You need to divide crime counts by population density. Otherwise you're just plotting population density.
Thanks for checking out the site and for the feedback. It's definitely something we're looking into. It's kind of an interesting question though because it somewhat varies by crime category. Take car break ins, for instance - this is more of a constant factor than a population density scalar because the number of parking spots is generally fixed on a per-block basis rather than scaling with population density. I thin…
Parking turnover probably scales with population density. One of the reasons parking is more expensive in big cities is to encourage people to move their cars sooner. Smaller cities will have more cars that never move, where larger ones will have fewer.
Re: Show HN: Play with an interactive heatmap of SF crime (and other cities)
#16You need to divide crime counts by population density. Otherwise you're just plotting population density.
It's an important truth that walking a mile in a high population density area puts you at a higher crime risk than walking a mile in a medium or low population density area.
Not really, since your chance of being a victim is divided by the number of people in the area.
Re: Show HN: Play with an interactive heatmap of SF crime (and other cities)
#17It's interesting to see how certain crimes (e.g. Assault and Robbery) have hotspots that map perfectly onto BART stops (16th & Mission, 24th & Mission).
Re: Show HN: Play with an interactive heatmap of SF crime (and other cities)
#18You need to divide crime counts by population density. Otherwise you're just plotting population density.
Is it actually true that crime in an area increases proportionally with population? Why would it? Extremely high density but near zero crime would be inside a large office building.
there's such a thing as a "target rich environment" but I always look at these maps as "where people are", college campuses, tourist attractions, crime is high because the number of marks is high, its a coincidence if many people happen to live there too
Re: Show HN: Play with an interactive heatmap of SF crime (and other cities)
#19You need to divide crime counts by population density. Otherwise you're just plotting population density.
It's an important truth that walking a mile in a high population density area puts you at a higher crime risk than walking a mile in a medium or low population density area.
It's the opposite - right? There are more gross crimes in the high-density area, but your chance of suffering one is much lower (all else being equal). Trying to apply statistics directly like this is generally inaccurate, but to the degree the numbers say anything it's the opposite of what you say.
Re: Show HN: Play with an interactive heatmap of SF crime (and other cities)
#20It's interesting to see how certain crimes (e.g. Assault and Robbery) have hotspots that map perfectly onto BART stops (16th & Mission, 24th & Mission).
it’s not surprising if you’ve ever lived in that area