Ability to save city layout from cityplanner to a file

chip12

I have an idea for an automated city layout planner that looks for the optimal layout. I would base the optimal layout search on the idea that the best layout is going to be straight roads radiating from Town Hall. The program would then try combinations based on building sizes until it found the most optimal. (Since CityPlanner data also includes the type of building, that could also be used as a secondary priority, attempting to keep similar buildings together.)

However, it would be a lot easier if there was a way to read the current layout directly into the program. I’ve looked at the JS for cityplanner, but I’m not a JS programmer (prefer Python). (Plus the comments are in German 🙂 ) But it still seems like it should be pretty straight forward to add a button and function to the city planner that saves the layout to a local file. I’m not picky about the format, as long as it’s something standard, i.e. XML, JSON, or even CSV.

I also tried saving the layout to the FOE-Helper server, but it doesn’t look like it does what I need either.

BTW: If the capability to generate an optimal layout already exists, someone let me know: as much I love solving these kinds of problems, I hate re-inventing solutions that someone else has already come up with.

noName

chip12 Now I thought about your problem with the city data. If the website ist saved via ctrl+s while the city is open, the HTML file should contain the city. Then you can parse the file. JSON could be better, but that’s a solution too.

noName

Only a genius could solve it always optimal efficiently(in polynomial time), as all problems related to bin packing are NP-Hard. But you could try it (or with not optimal solutions). Good luck, that would make things easier!

chip12

noName You may be right - I think I’ve figured out enough to determine the complexity is M² times N², trying all of the combinations of two buildings between two straight roads across all possible layouts of one or two buildings between two straight roads. However, it doesn’t “seem” intractable. I think I will find shortcuts.

noName

chip12 Now that’s interesting, how the problem is modeled matters. Maybe I made it a bit :-P more complicated than it is. There are some rules lik: put the shorter side to the road, put large buildings to the end of the road… Now I don’t know, but could a turn of the road make the solution better? I agree with you that it is worth investigating!

chip12

noName I can’t get my brain around allowing for the possibility of a turn in the road. I think I’m going to have to stick with the idea that all horizontal or all vertical roads will be the most efficient most of the time. 🙂 Nevertheless, as you said, it’s still a “bin packing” problem, which the math says should be intractable. (I had to go look that one up - it’s been a while since the class where we studied algorithm complexities.) Yes, the shortcuts you identified are the kind I was thinking of, but now that I’ve considered it, I’m not sure those change the complexity of the problem.

chip12

noName That’s a great idea! I’ll take a look at that.

mainline

@chip12

We have already thought about such a possibility. But that is not really possible.

With several million attempts it might be possible to optimise a small Bronze Age city, but as soon as the number of buildings increases, that’s it. This is no longer solvable.