I have a network of lines in layer 1 and a network of lines in layer 2, that always stay one side of the line in layer 1. I'm wanting to essentially determine whether a line is left or right of the other based on the direction of digitization.

  • What have you tried? The math seems simple enough (solve for the lines in the form of Y = mX + B, and the values B and B' with the sign of m should yield the answer). What if the sides change? – Vince Feb 26 at 11:39
  • @Vince Clearly a poor reflection on me, but I'm sorry to say that the maths isn't obvious to me. I'm a infrequent QGIS user and have simply searched for a processing tool that might assist. – Mardymonkey Feb 26 at 13:29
  • Suppose red and blue lines in this image are in layer 1, the black one is in layer 2. How do you decide which line (red or blue in layer 1) to compare with black line? The red line is on the left side of the black line. The blue line is on the right side of the black line. Are lines to be compared matched? – Kadir Şahbaz Feb 29 at 21:32
  • @KadirŞahbaz Hi. Thanks. Although this is unlikely with my data set, if that circumstance did arise I would need to assume that that the black line should be associated with the closest of the other lines. My data set it likely to have layer 1 as black and layer 2 with red and blue. – Mardymonkey Mar 1 at 8:02

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