enter image description hereI have a network of polylines between multiple nodes. All nodes are connected with lines in a two-way system (A->B and B->A). I want to show all the lines at the same time, but the problem is that they overlap and only one correlation are shown (A->B but not B->A). This means that the correlation just seems to be one-way instead of two-way.

How do I show them next to each other using QGIS?

  • Welcome to GIS:SE @RoKro! Does your line layer have an attribute to identify whether it goes from A -> B and vice-versa? If so, you could create a style (I prefer rule-based but categorised and graduated could also work) and add two style items to display both lines. Here you can add various options, including setting an offset for both your lines (i.e. give one style item a positive offset, the other a negative offset). – Joseph May 12 '17 at 11:05
  • Thank you for answering my question. Im not sure if your solution works in this case. The identifiers I have is the coordinates between the nodes (A= CoordX-CoordY -> B= CoordX-CoordY) and vice versa. – RoKro May 12 '17 at 11:36

You could add a new text field called 'direction' and then use calculate field with a case statement to work out if the line goes north or south. eg.

CASE WHERE coord_y2 > coord_y1 THEN "northerly" ELSE "southerly" END

You can then use a rule based style to offset the northerly and/or southerly lines

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