51–60 of 156 posts
I figure you're just rounding latlons to 2 decimal places and putting people in buckets?
Like mentioned the non-linearity with regard to latitude makes standard trigonometry useless. In my case I opted for the haversine formula (https://en.wikipedia.org/wiki/Haversine_formula) this is pretty accurate on the small range of 1km
Let me know what you guys think. The app was made to get people talking again to the people around them. I threw in automatically generated anonymous nicknames to lower the initial barrier a bit. Any advise on how to market/keep people engaged are most welcome.
Nice project. I'd suggest adding a like/ignore option to anonymous users. Also, don't miss this comment https://news.ycombinator.com/item?id=12804222
If it is exactly 1 km you could triangulate to find someone's location. A program to do that would do a bisection search along a line (faking coordinates for the location of the device) to find the point on the line where you transition to seeing the person's messages. Then, repeat along other two lines in different directions. Each transition point gives a circle of 1 km radius on which the person is present, and th…
Fyi, i ran a facebook group with 15 k. people for Belgium. The #2. A little bit late to the party of location based messaging concering Pokémon though ;)
If it is exactly 1 km you could triangulate to find someone's location. A program to do that would do a bisection search along a line (faking coordinates for the location of the device) to find the point on the line where you transition to seeing the person's messages. Then, repeat along other two lines in different directions. Each transition point gives a circle of 1 km radius on which the person is present, and th…
Doesn't look like the application shows the distance in the UI. As long as they don't leak it in the packets (hopefully they don't given how they claim anonymity) triangulation would require the target to be sending messages continuously on a consistent interval for you to detect whether or not they are at the 1 kilometre 'border.'
Can you make the zone adaptive so there are always at least a few people there?
This is one of the biggest decisions I've had to make based. The current implementation requires a huge critical mass before there are enough local users. Because as of now I'm not perusing making any money from the app, I opted to test the feasibility of the core idea. Talking to local people. One could of course argue that I could deviate from this slightly (variable range) to reach this critical mass.
How does this work if a person that is 500m away from me is currently chatting with someone 1.2km away… will it seem to me like that person is talking to himself (because his chat partner is out of my reach)?
If it is exactly 1 km you could triangulate to find someone's location. A program to do that would do a bisection search along a line (faking coordinates for the location of the device) to find the point on the line where you transition to seeing the person's messages. Then, repeat along other two lines in different directions. Each transition point gives a circle of 1 km radius on which the person is present, and th…
Using triangulation to pinpoint an other users location would therefore require to move in and out of range (while the targeted user is continuously sending messages). Thus significantly more difficult than if the actual distance measure was depicted in the UI or leaked elsewhere.
Finally closing the API to outside requests limits the ease with which the above could be automated. Any idea's for further improving these security measures are most welcome!
If it is exactly 1 km you could triangulate to find someone's location. A program to do that would do a bisection search along a line (faking coordinates for the location of the device) to find the point on the line where you transition to seeing the person's messages. Then, repeat along other two lines in different directions. Each transition point gives a circle of 1 km radius on which the person is present, and th…
Due to the fact that distance matching is done server side the application doesn't have any knowledge with regard to distance. The only knowledge one has is whether or not one receives messages from an other user. Using triangulation to pinpoint an other users location would therefore require to move in and out of range (while the targeted user is continuously sending messages). Thus significantly more difficult than…
That, or a number of co-operating clients located at various locations in and out of the range.
A simple fix would be to have every sender generate a random vector of random length 0-100 meters (and re-generate every time you've moved at least 100 meters, you don't want to regenerate if the sender doesn't move as you'd be able to zero-in on a prolific sender), and have the message "originate" from the end of that vector.
Anonymous messaging has proven in practise to be full of cruel gossip, hate speech, and bullying. I can't see a positive use for it, really.