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I've traced several lines that represent people's paths. Some of these lines overlap several times. I would like to get a view showing for each segment of my lines the number of line overlaps.

example1

example2

The methods I have used until now are:

  1. convert the lines into points (via Qchainge plug-in) and then create a heatmaps.
  2. using a procedure that shows the result in vector format (but very long):

Starting from the original layer "orig":

  • From "orig" create a layer of segments called "seg" by using Explode lines (QGIS).
  • From "seg" extract the center points of each segment, called "centr" using Point along lines with parameter 0.5 (QGIS).
  • from "centr" delete duplicates, call "centruniq" using Delete duplicate geometries (QGIS)
  • From "centruniq" create buffers of 50 cm called buff using Buffer (QGIS).
  • Run Count points analysis in polygon (QGIS) with input "buffer" and "centr", call output "count".
  • To "seg" element duplicates, call "seguniq" using Delete duplicate geometries (QGIS)
  • Join attributes from location of "seguniq" with count call final using intersects: segment vector with total number of passages attribute ("orig" elements)
  • style by category

I would like to ask if there was a faster solution that would allow me to display the number of line overlaps?

1

This may reduce the steps in the workflow.

(1) Explode lines (same as your first step)

(2) On the Exploded layer, Count the number of overlaps using an expression:

count('Explode', group_by:=geom_to_wkt($geometry))

Some use-cases will be:

(A) To set the line width:

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(B) To use it for the label:

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Input

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Output

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