4
votes
2answers
107 views

How to speed up a query for nearest linestring to point data

I have processed a Strahler stream order layer with a lot of river linestrings (type: Multilinestring) and their corresponding strahler number (see information here). Besides I have a point layer. I ...
0
votes
2answers
69 views

GeoServer create layer from PostGIS (data type point)

(Several days ago a user on gis stackexchange suggest that I should use OpenGeo (I was using geojson before). I succeed at what I was doing at that time, but now I have a different problem.) I was ...
0
votes
1answer
83 views

Defining a WHERE clause from a subquery for a query to create a handy view

It is about my implementation from an answer of this question. It is more an postgresql issue than a GIS issue, whereas it is about geometries and spatial queries. I want to create a view from the ...
3
votes
1answer
289 views

How to create linestrings with a definite angle and length, that are fixed to a point

I want to create linestrings with a definite angle (e.g. 160°) and length (e.g. 2m) that are fixed to a number of points of another linestring. So, I want to use the ST_DumpPoints function to find the ...
1
vote
2answers
124 views

Extract a LineString from LineString by two Points

I am using PostGIS2.0 and PostgreSQL9.3. I have LineString in Spatial-Ref 4326 like geom:= ST_GEOMETRYFROMTEXT('LINESTRING(60.7014631515719 56.8441322356241,60.7023117507097 ...
5
votes
2answers
217 views

How to detect duplicates and keep only one?

I've got a table with lots of points (200.000). Some of them are duplicates (not exactly but e.g. a metro station has eight entrances) and I want to keep only one of these metro entrances. I am able ...
0
votes
2answers
107 views

Manually add a new point to PostGIS table [duplicate]

I did accidently delete a table row - or well, in fact a whole subway station. My attempt to solve the problem was this PostGIS function: ST_GeomFromText('POINT(coordinates)') But then PostgreSQL ...
0
votes
0answers
54 views

How to format spreadsheet to input point data for later import to PostgreSQL

I want to create a spreadsheet to hold data from our cemetery. I will use the spreadsheet to get the data into a PostgreSQL database. What I dont know yet is the format that the point (positional) ...
5
votes
2answers
140 views

How can I join a spreadsheet to a point layer?

I have a layer with point data for the grave positions in our cemetery. We are gathering data from each headstone. If I enter the data to a spreadsheet can I later associate the spreadsheet with the ...
0
votes
1answer
192 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 ...
0
votes
2answers
1k views

PostGIS convert geography(Point,4326) to GPS

I got a database with a column of type geography(Point,4326), the data contained looks like 0101000020E610000092E057F66EF73140930035B56CBD4840. How can I convert it to GPS coordinates?
5
votes
1answer
173 views

Given 2 LINESTRINGs with common point, how to extract common point?

I have 2 LINESTRING geometries. I know both share a common point. Using PostGIS for Postgres, what is the cleanest way to extract the common point? Example with illustration: How do I extract the ...
5
votes
1answer
4k views

Simple PostGIS ST_Distance query for two points from the same geometry table?

Note: This question was published at Stackoverflow at first. I have a geometry table points_table with SRID 4326 and a few points in it. I need to find a distance between a pair of points (features) ...