Tagged Questions
0
votes
0answers
31 views
How to add vertices to existing linestrings in mysql?
Is it possible to add a Point at the end of a Linestring in MySql?
For example I have a Linestring as
Linestring(1 2, 1 4, 1 6)
and I want to add a Point
Point(1 7)
at the end (output should ...
6
votes
4answers
221 views
How to calculate the “depth” of a linestring using postgis
I have linestring features, which look like bent linestrings, hemicycles or convex or concave linestrings. In the moment I can select the distance between the startpoint and endpoint of each feature. ...
3
votes
3answers
239 views
How to extract POINT from a [LINE|MULTILINE]STRING
I'd like to create a vectorLayer in QGIS to display all the points that form a LINESTRING or a MULTILINESTRING stored in a PostGIS DB.
I think that I need to transform all points of LINESTRING (or ...
2
votes
2answers
324 views
Create point to a center of polyline
I'm trying to create a points in the middle of polylines. The data is now in the form of shapefile.
Is there an easy way to do this?
Cheers, Sanna
4
votes
1answer
194 views
adding multiple points to a linestring in PostGIS
Though a newbie to PostGIS, I'm having trouble solving something that I think should be farily straightforward.
I have two linestring tables, both consisting of simple, 2-node line objects: one has ...
6
votes
2answers
173 views
How to add vertices to existing linestrings?
If I have
Linestring(1 2, 1 5, 1 9)
and a
Point(1 3)
Is there any function that can merge linestring and point preserving the order
so output would be:
Linestring(1 2, 1 3, 1 5, 1 9)
0
votes
1answer
118 views
What is the fastest way to identify the two nearest linestrings using PostGIS?
I want to be able to identify the closest roads to two points that are generated through geocoding (a start and end address). The points will likely be near a linestring. Two approaches that I have ...
1
vote
2answers
386 views
How to offset point perpendicular to line direction in PostGIS
I have a postgis table of points, that are sitting on road centerlines (I've linear referenced them). And the second table with road centerlines themselves.
The point table also has a field roadid and ...
2
votes
1answer
335 views
How to create a efficent linestring out of geography points using postgis
I'm trying to create a linestring out of geography points. At the moment I'm doing it like this:
select ST_GeographyFromText(ST_Makeline(a.record_point)) from (
select (record_point::geometry)
from ...
2
votes
1answer
94 views
Access points with PostGIS
I have a PostGIS table with linestring geometries and point (A) on it and I need to detrimine points (M) which located M meters from A. Distance is measured along linestrings. Any thoughts?
7
votes
2answers
825 views
For a given feature find the closest point along a given path
Looking for a Java based (foss4g) solution for the following:
I am using a path along with a buffer to find features that are along the path. For each of the features returned I want to find the ...
