I want to iterate over a LineString and apply a filter so that I create a new LineString with those points that succeed in the test. How do I do that?
My goal is to find some outliers that are too far from the rest of the points in the path and remove them from the result. So I would like to measure the distance between each point in the LineString to make sure that they are not too far from each other.
You can St_dump your points from the LineString
order them by St_linelocatePoint and use a where condition to not use the points you don't want
and remake the LineString with St_makeline groupind by "id" of the line.
so something like this ... I guess
With points as (
select (St_dump(t.geom)).geom as geom, lt.id as lt_id
from linestring_table as lt)
select St_makeline(p.geom) from points as p,
from linestring_table as lt
where 'condition to keep point'
group by p.lt_id
order by St_linelocatePoint(lt.geom,p.geom)
ST_DumpPoints