1

I have 2 linestrings: Linestring 1 (-3 3, 6 8, 15 9, 22 13, 28.5 15.7) --> red color Linestring 2 (0 4.66666666666667, 6 8, 10 8.44444444444444) --> blue color

Actually both two linestrings are coincident

enter image description here

How do I get a part of linestring 1(red) that are not coincident with linestring 2 (blue) in PostGIS (as a multilinestring) ?

Improve this question
1
  • Welcome to GSE. Please perform the due diligence of reviewing the documentation on spatial operators before posting questions for which a one line answer is appropriate.
    – Vince
    Dec 13, 2014 at 19:32

1 Answer 1

Reset to default
3

I think ST_Difference is what you are looking for.

Improve this answer
4
  • No, the result is wrong, because there are some points in linestring 2 (blue) that are not part of linestring 1 (red). I have tried using both st_difference and st_symdifference, but the results are wrong
    – doel
    Dec 14, 2014 at 11:45
  • I mean that there are some points in linestring 2 (blue) that are no the vertexs of linestring 1 (red).
    – doel
    Dec 14, 2014 at 11:54
  • Perhaps you could state what output you expect, as ST_Difference answers your question as stated.
    – John Powell
    Dec 15, 2014 at 6:16
  • the output I expect is a multi linestring: fist part of red linestring, and the second part of red linestring -> multilinestring((-3 3,0.466667),(10 8.4444,15 9,22 13,28.5 15.7))
    – doel
    Dec 15, 2014 at 6:47

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.