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<div class="moz-cite-prefix">On 2015-01-03 19:36, Marc Gemis wrote :<br>
</div>
<blockquote
cite="mid:CAJKJX-QTr0jfQEwnUxtHkyuXmkDU92h1o-5v-UahhZB41coWkg@mail.gmail.com"
type="cite">
<div dir="ltr">so they are layers like I wrote in my first mail.
You call them patches.</div>
</blockquote>
Roughly equivalent, but a layer does not modify another layer and,
in the simplest implementation, a patch does.<br>
I like "patch" because a program patch contains modifications to a
program and these contain modifications to tags of ways. But the
term would be debatable. "overlays", "segments" ...<br>
<br>
I said I would stop writing about this, but I want you to have
pleasant walks <span class="moz-smiley-s3"></span><br>
BTW, I followed your advice. But as I can't have a dog I use a trick
I recommend: walking the neighbour's dog.<br>
And I made 5 happy ones, in order: the dog (unimaginable), my
neighbour, myself, the doctor ... and you.<br>
<br>
<blockquote
cite="mid:CAJKJX-QTr0jfQEwnUxtHkyuXmkDU92h1o-5v-UahhZB41coWkg@mail.gmail.com"
type="cite">
<div dir="ltr">
<div>
<div>Neverthless, each of those patches has to be related to a
way. So the server has to check whether the way to which the
patch is assigned still exists. Also it has to check whether
the points that indicate the beginning and the end of the
patch still belong to the street. It has to check this
because the way (street) might be repositioned. The patches
cannot exit on there own and has to be be associated with a
part of the street.</div>
</div>
</div>
</blockquote>
What server are you talking about? No server must check anything.
It's a matter of the consumer.<br>
The patches share at least their end nodes with one (or maybe more)
ways and that's how we know to which ways and over which span the
patches apply. Hence, your "problems" of "checking if the way
exists" or "still belongs to the street" do not exist. Basically,
finding the street means checking to which other way a node belongs.<br>
Also, if the street is "repositioned", the patches follow it
automatically as the nodes are moved.<br>
<br>
Basically, with the first type of patch, the only thing that the
consumer has to do is to detect the ways containing patch=*, to
split the other way at the end nodes, to override the patched tags
in between and to discard the patch.<br>
Doing that is certainly not overwhelming for a consumer. <br>
They do much much much more complicated things already.<br>
<br>
If I don't want to speak of patches any more, it's because it's a
constant habit on these lists to try very hard to disparage new
ideas instead of trying to understand their deep meaning and to
improve their defects.<br>
<br>
<blockquote
cite="mid:CAJKJX-QTr0jfQEwnUxtHkyuXmkDU92h1o-5v-UahhZB41coWkg@mail.gmail.com"
type="cite">
<div dir="ltr">
<div>
<div>Also when there is a patch saying that the maxspeed is
50, but a new 30 km/h part is introduced in the middle of
this patch, you have to "find" the patch with the speed,
split it and have 3 patches: 50 - 30 - 50.</div>
<div>So I still fail to see the simplification. <br>
</div>
</div>
</div>
</blockquote>
There is no need to have 3 patches. Think of how it's done and that
the 30 km/h patch is applied last because it patches not only the
road but also the other patch: a first <br>
<br>
I told you it's easy and great, but I don't claim that I have
imagined everything about it. <br>
The way to tackle such ideas it allow them to simmer gently, imagine
them in various situations and not walk on them with a gun.<br>
<br>
Cheers
<br>
<br>
<table>
<tbody>
<tr>
<td>André.</td>
</tr>
</tbody>
</table>
<br>
<blockquote
cite="mid:CAJKJX-QTr0jfQEwnUxtHkyuXmkDU92h1o-5v-UahhZB41coWkg@mail.gmail.com"
type="cite">
<div dir="ltr">
<div>regards</div>
<div><br>
</div>
<div>m</div>
</div>
<div class="gmail_extra"><br>
<div class="gmail_quote">On Sat, Jan 3, 2015 at 7:18 PM, André
Pirard <span dir="ltr"><<a moz-do-not-send="true"
href="mailto:A.Pirard.Papou@gmail.com" target="_blank">A.Pirard.Papou@gmail.com</a>></span>
wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">
<div bgcolor="#FFFFFF" text="#000000">
<div>On 2015-01-03 17:39, Marc Gemis wrote :<br>
</div>
<span class="">
<blockquote type="cite">
<div dir="ltr">
<div>I've been thinking a bit about your proposal
during my walk this afternoon. I don't see how it
helps when you have to turn a single way into a
dual carriageway or vice versa. Another problem
that I see is that those segments have to stay
coupled to a street. Which makes it harder on the
server to verify. As far as I see it now, the
implementation of the OSM API for edits on the
server is pretty straightforward and can handle
large loads. The more things that have to be
verified, the higher the load for a simple edit.</div>
</div>
</blockquote>
?<br>
<blockquote type="cite">
<div dir="ltr">
<div><br>
</div>
<div>But with your new explanation, it seems that
you make it even more complex, since you create a
segment / patch for each new combination of tags.
So when one wants to add an attribute to a street,
one does not have to split the street but X number
of segments that might already exist ? </div>
</div>
</blockquote>
</span> It seems that you did not understand. No patch is
created for each new combination of tags. They are created
only over the segment of the road that has tags different
from the rest and they contain only the tags that are
different. Creating a new patch does not splits existing
patches, they overlap like they overlap the main road.
Example:<br>
<br>
<tt>
------------------------------------------------
cobble stones patch</tt> <br>
<tt>---------------------------------------------------------------------------------------------------
road</tt> <br>
<tt>
-------------------------------------- 50 km/h patch<br>
<br>
</tt>50 km/h has been added without splitting anything and
a part of the road is both cobble stones and 50 km/h, a
new combination that does not split anything. Both
patches are separate, well isolated concepts that do not
interfere with each other and that can be changed or
removed without (almost) any concern for the rest without
changing anything else. <br>
<br>
Now, I'm sorry that I have to close this discussion
because I'm losing my time.
<div>
<div class="h5"><br>
<br>
<blockquote type="cite">
<div dir="ltr">
<div>With as only benefit that there is only 1
object that represents a street. Which is right
now a number of OSM-ways that accidentally have
the same name ? I think the current approach of
splitting a street is much easier then. We just
need an API to retrieve all OSM-ways that form a
street. Some might say "associatedStreet",
others say "Street" (cfr. discussion on
cycleways), or maybe some upcoming Overpass
feature might solve it (cfr a request from the
maker of [1])</div>
<div><br>
</div>
<div>AFAIK there are no restrictions implied by a
service road. Some navigation systems put a
penalty on service roads, as they are typically
not for through traffic.</div>
<div><br>
</div>
<div>regards</div>
<div><br>
</div>
<div>m<br>
<div><br>
</div>
<div>[1] <a moz-do-not-send="true"
href="http://osm.mueschelsoft.de/cgi-bin/render.pl"
target="_blank">http://osm.mueschelsoft.de/cgi-bin/render.pl</a>
-- shows all lane & direction information
for a street</div>
</div>
</div>
<div class="gmail_extra"><br>
<div class="gmail_quote">On Sat, Jan 3, 2015 at
1:47 PM, André Pirard <span dir="ltr"><<a
moz-do-not-send="true"
href="mailto:A.Pirard.Papou@gmail.com"
target="_blank">A.Pirard.Papou@gmail.com</a>></span>
wrote:<br>
<blockquote class="gmail_quote" style="margin:0
0 0 .8ex;border-left:1px #ccc
solid;padding-left:1ex">
<div bgcolor="#FFFFFF" text="#000000">
<div>On 2015-01-03 08:27, Marc Gemis wrote :<br>
</div>
<span>
<blockquote type="cite">
<div dir="ltr">I once read your proposal
on the wiki. The main drawback that I
see is that one will get an awful lot
of "layers" (or whatever you want to
call them). For each property you add
to a street a need to create a new
layer. After verifying of course that
there isn't already a layer with that
property. In that case you have to
split the layer at the right place.</div>
</blockquote>
</span> No. There is not a "layer" for each
property but for each segment of the road
that has a different sets of properties.<br>
Take a bridge as an example. With the
present scheme, the road is split in three
parts.<br>
With my scheme, it has only two parts: the
road and the patch for the bridge.<br>
And the patch for the bridge very clearly
contains all the tags that relate to the
bridge only, for example a special speed
limit and a name.<br>
Presently, if two paths arriving at a main
road are 50 m apart like this and a walk
uses the paths<br>
|<br>
<tt>--------<font color="#ff0000"><b>---</b></font>-------------</tt><br>
|<br>
then the road must be split as shown and the
red part becomes part of the walk.<br>
With patches, the road remains intact and
the patch is in the walk that is self
contained.<span><br>
<blockquote type="cite">
<div dir="ltr">
<div>I try to imaging how a UI to edit
that would look like. Or software
that uses that data. I wonder
whether it would much easier to work
with such a structure. hard to tell.
You are probably to much ahead of
your time with this proposal.</div>
</div>
</blockquote>
</span> The UI would make very clear what
the bridge is and the user would have a very
clear view of what its particular tags are
instead of being mixed with the tags of the
road. For the walk, the user dealing with
the main street would have very little
concern with it. The users would not have to
compare the tags of different splits and
wonder to what they relate. It's pure
simplicity.<br>
<br>
I have now devised a much more simpler way
to do patches than what I explained before.
But, as you almost say, I would lose my time
explaining that. Unfortunately, this means
that OSM will remain very complicated,
mapping restricted to gurus and subject to
many mistakes. For example, tagging a
simple turn restriction is NOT for Mr
Everybody and when I make a simple GPS trip
nearby, it goes through a track through the
meadows instead of the main road. That's
probably because the definition of a service
road is fuzzy and does not say if it's an
access restrictions or not. The mapper and
GPS writer probably had different points of
view about that. And that happens in
several places.<br>
<br>
Cheers <br>
<span><font color="#888888"> <br>
<table>
<tbody>
<tr>
<td>André.</td>
</tr>
</tbody>
</table>
</font></span><span> <br>
<br>
<br>
<blockquote type="cite">
<div dir="ltr">
<div><br>
</div>
<div><br>
</div>
<div>regards</div>
<div>m</div>
<div><br>
</div>
<div><br>
</div>
<div>PS, it is indeed pretty confusing
that something with one 'l' in one
language has two in the other, and
has another meaning in the second
language with one l.</div>
</div>
<div class="gmail_extra"><br>
<div class="gmail_quote">On Sat, Jan
3, 2015 at 2:34 AM, André Pirard <span
dir="ltr"><<a
moz-do-not-send="true"
href="mailto:A.Pirard.Papou@gmail.com"
target="_blank">A.Pirard.Papou@gmail.com</a>></span>
wrote:<br>
<blockquote class="gmail_quote"
style="margin:0 0 0
.8ex;border-left:1px #ccc
solid;padding-left:1ex">
<div bgcolor="#FFFFFF"
text="#000000">
<div>On 2015-01-02 19:01, Marc
Gemis wrote :<br>
</div>
<span>
<blockquote type="cite">
<div dir="ltr">
<div class="gmail_extra"><br>
<div class="gmail_quote">2015-01-02
17:11 GMT+01:00 André
Pirard <span
dir="ltr"><<a
moz-do-not-send="true"
href="mailto:A.Pirard.Papou@gmail.com" target="_blank">A.Pirard.Papou@gmail.com</a>></span>:<br>
<blockquote
class="gmail_quote"
style="margin:0px
0px 0px
0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex">J'ai
un jour écrit un
article décrivant
une méthode pour ne
plus devoir découper
les chemins mais ça
n'a intéressé
personne.</blockquote>
</div>
<br>
I've read somewhere that
navigation software will
split all ways at a
crossing in order to be
able to calculate all
possible routes. So the
merging is only needed
for rendering (in order
not to show the name
over and over again).</div>
</div>
</blockquote>
</span> Obviously.<br>
With my method, there is no
merging necessary because there
is no splitting.<br>
If a part of a way has different
tags, a sort of "patch" dummy
way is created that overlays
that part of the way and that
contains the tags that are
different. Difficult to explain
in 2 lines.<br>
<tt>---------------------------------------------------
</tt><tt>real highway with
common tags<br>
-------------
dummy way (patch) with
bridge=yes<br>
</tt>If the consumer wants that,
it can split the real highway,
merge the tags and get the
current situation. But it
doesn't have to. <br>
In a further step, with slight
software changes, the patch
could be the element of a
relation and relations would
stop splitting the ways
everywhere.<br>
Also, a turning restriction and
other things could be done with
very simple patches instead of
complicated relations.<br>
All in all very powerful and
easy to use, but, alas, it needs
software changes. Nothing
complicated but in the essential
parts.<span><br>
<blockquote type="cite">
<div dir="ltr">
<div class="gmail_extra">Nominatim
only shows the same way
when the classification
is different, see [1]
for a split street
showing multiple
results, and [2] for one
showing only one segment</div>
</div>
</blockquote>
</span> If you click on <span></span><span>(<a
moz-do-not-send="true"
href="http://nominatim.openstreetmap.org/details.php?place_id=152179547"
target="_blank">details</a>)</span>
of [2] you see that it's only a
split of Molenstraat and if you
click on <a
moz-do-not-send="true"
href="http://nominatim.openstreetmap.org/search?format=html&exclude_place_ids=152179547,90789266,57800141,152183937,58188920,57651969,89772878,126246678,2642012399,50709423,118353426,2642012397,2642012398,58361979,98773793,57793661,50786385,80736363,123201401,100889764,15832600&accept-language=en,fr;q=0.8,wa;q=0.6,ru;q=0.4,nl;q=0.2&viewbox=4.38%2C51.11%2C4.41%2C51.09&q=Molenstraat%2C+rumst"
target="_blank">Search for
more results</a> you get
another split and <a
moz-do-not-send="true"
href="http://www.openstreetmap.org/search?query=molenstraat%20rumst#map=16/51.1009/4.3920"
target="_blank">it's not very
clear at all how that street
is split</a>, it looks like
Nominatim is only showing parts
of the splits.<br>
It would obviously work better
if there were no splits but
patches.<span><font
color="#888888"><br>
<br>
<table>
<tbody>
<tr>
<td>André.</td>
</tr>
</tbody>
</table>
</font></span><br>
PS: Oops, I first thought that
"molen" were moles and I
wondered if they were under the
street and <a
moz-do-not-send="true"
href="http://www.openstreetmap.org/way/166577477"
target="_blank">drinking a cup
of coffee</a> <span><span>
;-) </span></span> They
are in fact mills <a
moz-do-not-send="true"
href="http://www.openstreetmap.org/node/259975902#map=19/50.52639/5.52305"
target="_blank">like this
water mill</a> that I just
mapped and that's probably the
best known in Belgium.<span></span><br>
</div>
</blockquote>
</div>
</div>
</blockquote>
<br>
</span></div>
</blockquote>
</div>
<br>
</div>
</blockquote>
<br>
</div>
</div>
</div>
</blockquote>
</div>
<br>
</div>
</blockquote>
<br>
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