On 17.01.2013 16:01, Gerd Petermann wrote:
reg. test data: I did not yet try to understand why a short arc brakes
routing. I assume it is because you can't calculate the bearing with
an appropriate precision?
I just know that I see error messages like "road ... contains zero
length arc at ... "
or "road ... contains consecutive identical nodes at ... "
when I omit the removeShortArcs call.
So, I'll try to run the first version of the patch against many tiles
and see what happens. If I don't find a problem in Europe,
it is likely that we don't need iteration.
OK?
Gerd
>
The reason As far as I can remember is that if we have the following
situation
#
#
#
--- O UUU ---
#
#
#
Now consider both # and - U and O stand for streets. O must not be
shorter than the routing resolution (which is twice the minimal distance
we can put points), else O will be unroutable.
I found out about it, by having a very short stretch of a road on a
bridge, where directly after the bridge (or was is actually sharing a
point with the bridge?) a crossing pops up. As soon as we made sure that
O is ~5.4m the routing worked again.
Im not sure if
--- UUU --- with UUU being shorter than 5.4 works though. (UUU being e.g
a bridge).
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