I have

  • a vector layer with a number of points which correspond to magnetic targets
  • axis retrieved from AutoCAD

The task is to project the points on the axis and then calculate the distance of each projected point from the start of the axis. Ideally, I would like the calculated distance to be on the same table as the points so I can know which point each distance refers to.

Moreover, it would be nice to know the perpendicular distance of each point from the reference axis. A picture of the above problem is also presented below.


1 Answer 1


Start the Field Calculator on your point layer's attribute table.

Create a new field by an expression below:

line_locate_point(geometry:=geometry(get_feature('NaMy_FSR', 'id', '1')), point:=$geometry)


  • Your line layer name is : NaMy_FSR
  • The line has an attribute value 1 in the 'id' field. (You can use any field to distinguish the line).


As to the distance the perpendicular distance of each point from the reference axis;

Not sure if this works, but will you try:

distance(closest_point(geometry(get_feature(‘NaMy_FSR’, ‘id’, ‘1’)), geometry), $geometry)


distance(closest_point(geometry(get_feature(‘NaMy_FSR’, ‘id’, ‘1’)), $geometry), $geometry)
  • Is there a way to obtain the projection distance from the line ?
    – Pand
    Commented Jan 10, 2019 at 12:28
  • Hi @stamatis Yes, I think it is possible. Will you post a new question or edit your current question to include this additional requirement?
    – Kazuhito
    Commented Jan 10, 2019 at 12:38
  • Question edited. Looking forward for the answer :)
    – Pand
    Commented Jan 10, 2019 at 12:47
  • @stamatis Added another syntax in [EDIT] section. Hopefully it works, but other specialists at this board may help you better.
    – Kazuhito
    Commented Jan 10, 2019 at 12:53
  • 1
    @stamatis Both questions are interesting, definitely. Will you post them as new questions? For the first one, I recommend to look into azimuth() function. I have no idea about the latter one, which would require experts' help.
    – Kazuhito
    Commented Jan 10, 2019 at 13:31

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