Somebody know how can I calculate the x,y,z,m parameters from a MultiLineStringZM in Postgis?

I would like to know x,y,z and m from the points what are made the polyline.

When I try calculate it by this way "*st_x,st_y, st_z, st_m*" postgis go up an error message: ERROR: Argument to M() must be a point

Any idea?



  • 1
    Your problem is, that st_x() works with a single point. Your current geometry object is a MultiLineStringZM. What is the 'idea', 'target' of using the function..., please elaborate.
    – Styp
    Jul 2, 2013 at 12:26
  • 1
    I would like to know what are the x,y,z,m coordinates of each point that is compositing each polyline. But I don´t know how can do it.
    – Acicate
    Jul 4, 2013 at 7:05

1 Answer 1


Try this function: http://postgis.net/docs/ST_DumpPoints.html

The rest should be straight forward (ST_X, etc).

I hope it works out for you!

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