Tuesday, 12 April 2011

Windermere refilled

Having tidied up the data, tweaked the rendering, and speeded up the whole process I finally got round to regenerating my 1/2" maps, only to discover that Lake Windermere had disappeared. Refilling it has taken a while.

Generating the foreshore from Ordnance Survey VectorMap District was a bit fiddly, but a lot more straightforward, and I think the result is worthwhile. Thanks, Chris for pointing me in the right direction.

There are two more examples here and here.

8 comments:

William said...

I've always been a map geek. In fact, if you want me to shut up, just pass me a map of somewhere I've never been!
Having sort of hinted at my bona fides there, I'll now come straight to the point:
I absolutely love these new maps of yours!
Will you ever publish them for all of the UK?
(Hint: I live in Plymouth and REALLY wouldn't mind one for my area!)

Many thanks for your efforts!

gom1 said...

Thanks very much for your comment William. I'll see what I can do.

gom1 said...

I've not checked it yet, but here's South Devon. I'd be interested in comments - and I'll try to fix what I can. No plans to cover the whole country at the moment though.

gom1 said...

And Cornwall, with a bit too much sea. As above - I've not checked it but I welcome comments, and will fix what I can.

William said...

Thank you so much!
If I can repay you in any way I'd be happy to!

William said...

I'm pushing my luck here, but is there any chance at all of asking you for just one more map, covering North Devon, and to overlap slightly with the South Devon one?

Thank you very much in advance, and please let me know if I can do anything in return?

William said...

Also, which application do you use to render the maps?

gom1 said...

Things went a bit quiet because I've been re-engineering it all, and in the process I accidentally wiped a lot of stuff. However, it's more-or-less back up and running now, with a few outstanding glitches to fix.

There are various enhancements, and in the process I've reworked it all using a different projection (based on Ordnance Survey grid references, rather than the WGS84 projection using latitude and longitude). That makes the proportions a bit more familiar. Because of the amount of reworking it may be that some errors have crept in. For example I know there are some missing contour lines in Scotland, but I've not spotted any in England yet.

There is a selection of renders here, including North Devon. I'm trying to stay fairly close to the original coverage for each of these, but it's a bit hit and miss:

Cornwall

South Devon

North Devon

Southern Lakes

North Northumberland

They are rendered using Mapnik. I extract OSM data from the planet files, and add stuff that people like the Ordnance Survey have released into the public domain. That all goes into my own GIS database based on postgresql (with postgis extensions). That's where I munge some of the descriptions. Then I render using mapnik, and add the borders, legend and what-not using perl-magick (a wrapper for image-Magick). The code that I have used to glue it all together is in perl. The whole lot is running on Ubuntu, on a very old, and under configured PC. Fiddling around with the data takes for ever, but once it is sorted each map takes from 10-20 minutes to render.

It's really difficult to spot things that I have missed, so the best repayment you can make is to point out any errors or inconsistencies that you find. And (of course) to continue adding useful detail to the OSM database. I hope you still enjoy these after the changes.

Thanks for your interest.