Show HN: Play with an interactive heatmap of SF crime (and other cities)
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Re: Show HN: Play with an interactive heatmap of SF crime (and other cities)
#2You need to divide crime counts by population density. Otherwise you're just plotting population density.
Re: Show HN: Play with an interactive heatmap of SF crime (and other cities)
#3You need to divide crime counts by population density. Otherwise you're just plotting population density.
Depends on how the map is being used. If I'm looking to avoid traveling through neighborhoods with a high robbery risk (e.g. as a tourist), I'd prefer absolute numbers vs. per capita.
Re: Show HN: Play with an interactive heatmap of SF crime (and other cities)
#4You 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 think we might try to give users the option of dividing by population density but allow them to toggle this on/off.
Re: Show HN: Play with an interactive heatmap of SF crime (and other cities)
#5Nicely done. Longer term historical data would be nice too, for comparison or trends. It should be available as these sorts of crime maps were all the rage 10-15 years ago.
Personally, I would prefer that the crimes filter panel automatically hide itself when I click on the map after selecting my filter.
Kudos.
Re: Show HN: Play with an interactive heatmap of SF crime (and other cities)
#6You need to divide crime counts by population density. Otherwise you're just plotting population density.
Depends on how the map is being used. If I'm looking to avoid traveling through neighborhoods with a high robbery risk (e.g. as a tourist), I'd prefer absolute numbers vs. per capita.
That's probably not the correct analysis, because the number you're trying to estimate is not P(a crime occurs near you), it's P(you will personally be the victim of a crime). Crime rate over density won't necessarily do that either (since the population density of a primarily commercial+touristy area, e.g. Fisherman's Wharf, is << the number of people who are present there on a given day), but neither does raw count.
Re: Show HN: Play with an interactive heatmap of SF crime (and other cities)
#7You 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…
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Re: Show HN: Play with an interactive heatmap of SF crime (and other cities)
#8Earlier quoted context omitted.
Depends on how the map is being used. If I'm looking to avoid traveling through neighborhoods with a high robbery risk (e.g. as a tourist), I'd prefer absolute numbers vs. per capita.
That's probably not the correct analysis, because the number you're trying to estimate is not P(a crime occurs near you), it's P(you will personally be the victim of a crime). Crime rate over density won't necessarily do that either (since the population density of a primarily commercial+touristy area, e.g. Fisherman's Wharf, is << the number of people who are present there on a given day), but neither does raw count…
I mean, I'd also be pretty interested in avoiding P(a crime occurs near you), especially as a tourist.
Re: Show HN: Play with an interactive heatmap of SF crime (and other cities)
#9You need to divide crime counts by population density. Otherwise you're just plotting population density.
That depends if people care more about crime happening to them or crime happening around them.
Re: Show HN: Play with an interactive heatmap of SF crime (and other cities)
#10Nicely done. Longer term historical data would be nice too, for comparison or trends. It should be available as these sorts of crime maps were all the rage 10-15 years ago. Personally, I would prefer that the crimes filter panel automatically hide itself when I click on the map after selecting my filter. Kudos.
Thanks! Yeah, we definitely plan to add long term historical data and give users the option of diving deeper into the trends. Should be in the very near future. Thanks for the idea of auto-hiding the sidebar on a map click - that's very intuitive. Will probably push an update later today to add this.