On 15/02/2018 08:52, Tom Pfeifer wrote:
On 14.02.2018 17:39, Dave F wrote:
https://www.openstreetmap.org/node/5408566797
It appears that you already engage in an edit war, although half a
dozen people here tell you, from a variety of perspectives, that you
are wrong.
https://www.openstreetmap.org/changeset/56352276
The previous mapper move the roundabout to an *inaccurate* location in
order "to fudge" a separating section. I legitimately reverted it so it
was accurately located as per a survey I perform on the ground.
It would help to maintain objectivity to leave out any rants about
particular programmers of particular software. I have seen other
routing engines fail when the situation occurs that you have created.
On 14.02.2018 18:27, Dave F wrote:
> This would only occur if there was no check to see if it's a
roundabout first:
> * Enter
> * Check if roundabout
> * (While still on the same node) Start counting entrances/exits
In which routing engine did you implement this? From which experience
do you speak?
Or is it just pseudocode that fell off your sleeve without being
tested in an implementation?
If a router is unable to perform simple checks it's not worth its salt.
On 14.02.2018 21:44, Mark Wagner wrote:
In the general case, a router only needs to consider the ways that a
route actually passes over when creating directions. By mapping a
roundabout entrance and exit sharing a single node, you've
introduced a special case: the router now needs to check all ways
connected to that node to see if any of them is part of a roundabout.
Yes and to reiterate, to separate roundabouts from non-roundabouts,
How does the 'roundabout' tag not "separate"?
you would need to check that special case not only at roundabouts, you
would need to check its absence at _any_ node connecting _any_ two
road segments, even if these are not junctions. You would need to
check if there starts a roundabout segment or not, and if all segments
of such roundabout loop back to the original node.
As the check you propose is against the basics of graph theory which
is behind routing algorithms, it would create an immense performance
burden on the algorithms. That would make you mourn about the skills
of the programmers, again.
May we ask you to undo your revert in CS 56352276? You still have not
explained how the two node solution "fudge OSM".
No one's explained why the single node fails. It works fine at crossroads.
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