OpenGeofiction
Hey you guys,
I was wondering wether there was going to be an update of the OGF: Area table anytime soon. The last update was several months ago, and I would realy like to know how big my provinces are. I wouldn’t mind helping out once in a while if it is a lot of work for the admins to update the page, but i don’t know how the areas are calculated…
Thanks in advance,
TRJ
Discussion
Comment from histor on 21 January 2016 at 11:44
This update runs only from time to time and is starting manuell.
Comment from Luciano on 21 January 2016 at 12:05
It is possible to find the areas of relations in JOSM, although it takes a bit of work. Using the measurement plugin, you can select the ways in the relation, combine them into a single way, get the measurement, and then “undo” the step. No damage done. I can do each relation in less than a minute with some fast keyboard work using JOSM keyboard shortcuts.
I often get my areas that way, because the OGF:Area Table is just the output of a script that Thilo runs occasionally on the server, at his convenience. It might be rather resource-intensive (same as coastline render updates), which is why he runs it infrequently.
Comment from zero on 23 January 2016 at 00:36
Hi TRJ,
I also wanted to find out the areas of my land masses, so about a month ago I wrote a program to compute them. With a few additions to the code I was able to run it on your provinces also.
Please keep in mind that the values are approximate. The accuracy depends on what model of the Earth is used in the area computing algorithm. I used a spherical model with a radius of 6371.0088 km, which gives acceptable accuracy around the globe.
Here are the values (expressed in square kilometers): Forrintië: 448383.97 Thaxen: 28618.901 Opper-Ewaland: 10269.464 Neder-Ewaland: 12502.397 Siltland: 19527.681 Kasselen: 28475.477 Meernbant: 65455.765 Doesburgh-Leen: 22094.057 Aatresië: 23404.114 Reinsburg: 7090.093 Furen: 12202.278 Londsvoude: 62936.003 Negenburgen: 23052.167 Thaxen-Leeuwen: 25433.097 Jelre: 23387.822 Hessau: 9726.888 Istirië: 12035.945 Batuwerland: 12514.903 Griffië: 18248.788 Drijschen: 31408.133
Hope it helps. Cheers
P.S. You have some errors in your province borders: 2 extra boundaries between the 2 eastern most provinces, and a disconnected node in the north eastern corner of Thaxen.
Comment from Luciano on 23 January 2016 at 01:49
@zero - I too, have been toying around with some area-computation algorithms, but I’m not very good at that kind of thing. Is it possible you could share your code, or share where you got it? I think we’re seeing a situation where the OGF:Area Table is getting too big to be centrally manageable (Thilo had to split his recent run into two pages to make the wikitable fit), so having a number of hacker-users with access some publicly available code to allow people to make their own computations might be the best long-term solution.
Comment from zero on 23 January 2016 at 07:50
Hey Luciano,
I’m glad to hear that my code could be useful to the OGF community. Unfortunately I can not share it at the moment for two reasons: 1) it’s not general enough (I didn’t have much time to work on it, so I wrote it to solve specific problems); and 2) I have a very strict IP contract with my company, so I have to ask permission for any code I wish to open source. But I’m working on solving these two issues, so maybe in the near future I’ll release it on GitHub. Until then, I’m happy to assist anyone as my time permits (read: in some week-ends and very rarely on weekday evenings). :) If it helps, this is what my code does:
As you can see, it’s not very elegant; it just does the easiest thing possible to solve the problem.
zero
Comment from TRJ on 25 January 2016 at 16:33
Thank for all the help. The code-thing is really cool, I hope you can release it in the future.