Bug report #9857: Hub lines tool needs documentation - QGIS Application - QGIS Issue Tracking

Bug report #9857

Hub lines tool needs documentation

Added by Anita Graser over 10 years ago. Updated over 9 years ago.

Status:	Closed
Priority:	Normal
Assignee:	Victor Olaya
Category:	Processing/Core
Affected QGIS version:	master	Regression?:	No
Operating System:		Easy fix?:	No
Pull Request or Patch supplied:	No	Resolution:	fixed/implemented
Crashes QGIS or corrupts data:	No	Copied to github as #:	18385

Description

Trying to test the Vector analysis tools | Hub lines tool using QGIS sample data (airports and populated places).
The tool always fails with the error "No spoke/hub matches found to create lines" even though Distance to nearest hub tool - which also has a line output option - succeeds.

Does Hub lines only work for point layers which share common ids instead of finding the nearest hub? If that's the case, the GUI does not make that clear.

History

#1 Updated by Alexander Bruy over 10 years ago

From MMQGIS help

The hub lines tool creates hub and spoke diagrams with lines drawn from points on the "Spoke Point" layer to matching points in the "Hub Point" layer. Determination of which hub goes with each point is based on a match between the "Hub ID Attribute" on the hub points and the "Spoke Hub ID Attribute" on the spoke points.

The lines are output to a shapefile of lines and each line inherits all attributes from the matching spoke points.

No attempt is made to transform between coordinate systems, so using source and hub layers with different coordinate systems may yield odd and undesirable results. This tool also does not incorporate any kind of network awareness (e.g. as when dealing with streets between city blocks), and all lines are straight lines from spoke to hub.