OpenStreetMap

stevage's Diary Comments

Diary Comments added by stevage

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Map Validation at Facebook

I’m curious about example 10. First, what imagery is that? It doesn’t look like anything I could find in iD.

Second - how confident are you really that there is a bridge there? There’s at least three ways that a waterway and a road can cross each other: bridge, culvert, ford.

It’s not totally obvious to me from that image that there is a bridge here - could easily be a culvert, as indeed there is a culvert a very short distance northeast. An outside chance of a ford - certainly from the image sources in iD there’s nothing to indicate that that isn’t the case.

IMHO, a “waterway crosses road without bridge tag” problem is not really a problem in itself. It simply indicates there is some missing information, and isn’t worth running the risk of introducing erroneous information with false confidence.

OSM redaction results...the map is okay (in Seattle, that is)

Same reaction here - I’m in Melbourne, Australia. Plenty of stuff deleted around here - but much worse in other parts of the country. Sigh. I think 5 years from now, everyone will be scratching their heads and asking “so, remind me why we did that again?”

On Tracing from Poor Imagery

I think it’s a reminder that you don’t have to get it perfect first time. There wasn’t much wrong with the original tracing - it was perfectly fine for navigation. If the original tracer decided “this imagery isn’t perfect, I’m not going to use it”, there wouldn’t have been any highway at all.

Imperfect is much better than nothing.

How to deal with dirt roads?

Interesting question. I'd ask on help.openstreetmap.org.

Potlatch 2 save button moved to opposite side of page---ugh. Please change it back...

(err, by "change", I mean, divergence from their initial expectations)

Potlatch 2 save button moved to opposite side of page---ugh. Please change it back...

Compdude: much easier for established users like us to get used to the change (seriously - I was used to it after about three clicks), than for incoming newbies who will, be definition, never get used to any change.

histoire

Les voila ! http://osm.org/go/eqfnAGerQ-- :)

Serieusement, comment tu vas faire, en visitant les sites directement ? Ca a l'air sympa.

How not to use OS Locator

"it" meaning, the name, or the street? If the street never existed, how would you tag that? not:highway=residential?

Opencyclemap

It updates fairly infrequently. I don't know if there's a regular cycle, but something like every 2-3 weeks is typical I think.

OSMing without a GPS?

I've done it a couple of times. Once I went and did all the laneways, footpaths and bike paths here: http://osm.org/go/uG4Ggq7K. I just drew a map from what I'd traced from imagery, then wrote notes on it. It was a bit tedious and fiddly, but I was riding a bike, and stopping every 50m is like that...

Calling Australians

Nice fine print there. "Quit whining. Even though all your nearmap-sourced contributions will be deleted when OSM goes ODBL, you should rejoice in the fact that you can at least tick a box. Hundreds of hours of work deleted, but you get to TICK A BOX."

Or maybe I'm misunderstanding you.

What constitutes a track ?

Btw it's good to ask these quetsions on the official question site, http://help.openstreetmap.org/ .

SHC

C'est-à-dire ?

last entry

The strange thing I keep seeing again and again is the attitudes of people on the two sides: there's a cold, harsh, unsympathetic attitude from the pro-licence-change people. There are frustrated, well-meaning but impotent pleas from the other side. It's very sad to see good people go.

I've tried and failed to understand the licence issues. I can't believe it could be so complicated, but there has been a real failing of the people involved to communicate honestly and in good faith about the changes. Yes, the mailing lists are open. That's not the same thing. Dismissing the complaints of "the Australians", who will lose vast amounts of data (myself, hundreds of hours of work) as "FUDing trolls" is not good faith.

It's sad, but I don't see many people expressing sadness - I see the kind of vengeful "good riddance" comments exemplified above.

How to draw correctly sized round circles in Potlatch 2.

Hi Alex, no worries about being a 'back seat driver' - it's open source after all. You can see the code here: http://trac.openstreetmap.org/browser/applications/editors/potlatch2/net/systemeD/potlatch2/tools/Circularise.as

That mindprod.com link you post also suggests that the use of Math.pow to compute squares could be causing a problem.

One other thing to remember about this issue, though, is that the goal is usability: to compute a circle that reflects as closely as possible what the user wanted. So this very simplistic algorithm I've implemented has some deficiencies (eg, a way with lots of nodes at one place, and a single outlier, will produce a circle clustered around all the nodes) - but they're not necessarily bad for usability. So I think the needs of a centroid computation for Circularise are different from the needs of the WayUI centroid computation (which has to put the label for a way in the "middle" of it...)

How to draw correctly sized round circles in Potlatch 2.

Ok, I've added this in http://trac.openstreetmap.org/changeset/25276.

How to draw correctly sized round circles in Potlatch 2.

Hmm, interesting, I just implemented the naive "average X and Y" algorithm the OP suggested and...it works great. Perfect results every time. I'll have to do some more testing to make sure I'm not missing anything, but it seems a lot simpler than the "mathematically correct" algorithm currently implemented, and without the bugs.

(Btw the WayUI algorithm is buggy in the same way as the Circularise one, but presumably the results just aren't as noticeable.)

How to draw correctly sized round circles in Potlatch 2.

Had a closer look. Actually, circularise seems to work most of the time for me (at least in the development version). But I found some cases (mostly rectangles) where it is calculating the distance wrong, and probably the centre too (which would cause the distance miscalculation). With some of these, nudging the whole rectangle up or down a tiny amount would cause huge differences in the calculations - shifting the centre east or west of the original centre.

I think the best solution will be to move the centroid calculation from WayUI into Way (as already suggested in the code), and to use that in Circularise. Rather than having two different centroid calculations, at least one of which is clearly buggy.

How to draw correctly sized round circles in Potlatch 2.

Nice writeup. Circle has never worked for me in P2, but others claim that it does. The centroid is already calculated for every closed way. The only issue in implementing what you suggest is potentially losing history of some of the nodes, since you're basically talking about discarding all the old nodes and creating new ones.

I do like your thinking though.

I accept new ODbL licence

But do you understand and agree with the new Contributor Terms?