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mach0 / qchainage

Chainage Plugin for QGIS
GNU General Public License v3.0
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Qchainage not starting at the end of poly line #16

Closed nbombers closed 5 years ago

nbombers commented 5 years ago

I'm trying to calculate a 10m chainage on a layer single part polylines I have in QGIS but when I use the plugin the chainage starts at mid point on the lines. It appears as if it's selecting random vertices to start and begin the chainage qchain

mach0 commented 5 years ago

Hi and thanks for the report. Is the polyline available somewhere? I had such cases too, but only with polylines that were merged with one part going in the "wrong" direction. So before merging the polyline every line should point in the same direction.

nbombers commented 5 years ago

@mach0 thanks for the info, I've gone back to the segments that were merged into the polylines and noted that some of them are going in opposite directions (right at the location of the chainage errors) we'll have to sort that out.

mach0 commented 5 years ago

@nbombers let me know if everything works afterwards (and yes I know I should update the plugin, but I'm missing the time) ;)

nbombers commented 5 years ago

@mach0 unfortunately still having the same issue - even after rectifying the segment directions. The plugin seems to be using the 1st vertex in the dissolved layer which is not necessarily the first in the polyline qchain

mach0 commented 5 years ago

Hi! Do you have a sample for me to investigate? Is it possible that it might be something like this: https://gis.stackexchange.com/questions/271341/cleanly-splitting-polylines-reordering-vertices-in-qgis

mach0 commented 5 years ago

could you already solve this?

nbombers commented 5 years ago

hi @mach0 we pulled our chainage from our roads database and overlaid that on the lines. We never resolved the issue with the vertices

mach0 commented 5 years ago

@nbombers thanks for your reply. Can you provide a sample line for me so that I can probably look at the problem?

mach0 commented 5 years ago

closing as the issue seems with the data