A sequence of point coordinates referring to the line segments connecting them, as used to represent a one-dimensional feature or object.

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3
votes
2answers
138 views

Find gap in / endpoints of linestring

I have a set of features of type linestring. I'm trying to polygonise the linestrings and assumed that they were closed (naive me :) ). Of course some were not closed and I'm trying to locate the gaps ...
2
votes
2answers
137 views

How to extract a new linestring vector from a existing multipolygon in QGIS?

What I want to do: create a new line (named linestring in Postgis?) from existing multipolygon layer in Postgis. Purpose: once these lines are created, I'll run some distance calcs from specific ...
0
votes
2answers
116 views

Create point on a line with given distance from end in PostGIS

Does anyone know how to create points along a line (MultiLineString geometry) with a given distance in PostGIS? I'd like to create points at a regular distance over a line, which represents a ...
3
votes
1answer
173 views

MySQL select linestrings into a multilinestring

I have a mysql column of linestring type with 2000 linestrings (high water mark values to be more specific). I want to merge them into one multilinestring so i can see what the shape of these values ...
3
votes
1answer
101 views

How to find intersected line is from left or right on another line?

There is a main LineString and its direction is known. I want to find the side of intersected lines to this main line. Example image: Black line is main LineString and red one is intersected ...
1
vote
1answer
35 views

Finding and merging lines that touch in PostGIS?

I would like to select and merge segments that touch like in the image below. My table contains single segments with their own id (shown in the figure), I just want to isolate single "group" of ...
1
vote
1answer
69 views

Closed Linestring

I've created a linestring using st_makeline(). When I draw this linestring using QGIS it always makes it closed. The start and end points are not the same and I verified by using st_startpoint() and ...
1
vote
1answer
46 views

Linestring to CartoDB api

I want to add a linestring to a CartoDB API web app for one time use, I have SQL statement being ran at the same time and just want the linestring in the SQL statement to be displayed.
1
vote
1answer
90 views

Display linestring on Cartodb with SQL

I have a Cartodb api for a separate map, I need to display a linestring for each time the sql is run, but not store the linestring in the database.
0
votes
1answer
21 views

Linestring in OpenLayers doesn't draw

I don't understand why my code doesn't work. If the map is displayed, the line is never drawn: <script> var long_deb = -1.28627; var lat_deb = 43.49829; var long_fin = -1.29394; var lat_fin = ...
0
votes
1answer
248 views

Check if a point cordinate is between linestring cordinates

I know that, linestring is a vector and if i want to check that, if point cordinates are between linestring begginning and ending cordinates then i need to use vector comparison (x2 > x && ...
0
votes
1answer
138 views

How to transform isolines to isopolygons with postgis?

I have a table a postgis table of isolines that's defined like this: CREATE TABLE myisolines ( gid serial NOT NULL, isotime timestamp without timezone, val numeric(10,4), geom ...
0
votes
1answer
32 views

Geometry conversion problem.Data loss

I was trying to convert a roadnetwork table.Its geometry contains both MULTILINESTRING and LINESTRING.I converted all the MULTILINE string to Linestring using the query update all_india_merge set ...
0
votes
1answer
94 views

Simplify table of linestrings

I have a PostGIS table of linestrings representing a road network. I want to simplify the geometries such that only lines that connect road junctions are stored. At the moment the table has a large ...
5
votes
0answers
190 views

How do I simplify the straight sections of (multi)Linestring in PostGres/PostGis leaving the curved sections untouched

I have (multi)linestrings containing upwards of 5000 points and I want to perform two simplifications possibly using Ramer Douglas Peucker or alternative methods in PostGis The (multi)linestrings ...
5
votes
0answers
690 views

ArcGIS Kernel Density with polyline, search radius / bandwidth calculation

I'm conducting a density analysis of a series of polylines and I'm hung up on determining an appropriate search radius. The default calculation performed by arcgis is to take the shorter dimension ...
4
votes
0answers
246 views

PostGIS 2.0 st_geomfromgml using LineString fails with invalid GML representation

I am attempting to insert a geometry into a table using the st_geomfromgml function. The GML is being sourced from a Geoserver WFS request. The function call looks like this ...
3
votes
0answers
24 views

Postgis - Construct linestring of length N

Give a table of linestrings (roads) ogc_fid, wkb_geometry And a road with ogc_fid = X In postgis how could I construct a linestring that is of length Y metres made up of roads starting from road ...
2
votes
0answers
44 views

Extract from a linestring layer, groups of linestrings to a multilinestring objects layer

I've got a linestring layer with thousands of linestrings. I want to extract groups of linestrings to individual multilinestring objects. In the following picture you can see a part of the layer ...
2
votes
0answers
49 views

SQL Server, Given a linestring with M value, what is the location of this other M value

We are investigating migrating a prototype into SQL Server (azure). We have LineStrings that also have M values. What we would like to do is given another M value find out what its geographical ...
2
votes
0answers
182 views

Get Distance between two point on linestring using mysql Spatial

I have a linestring and two point on this linestrin according to my picture i want distance between two point as base of linestring please hellp me
2
votes
0answers
255 views

Splitting Line.shp at Point.shp with Python/ogr

I'm trying to modify some ESRI Shapefiles using Python with gdal/ogr module. What I want to do is quite simple, but I didn't find any solution by now. I have two shapefiles: (1) Lines.shp and (2) ...
2
votes
0answers
267 views

PostGIS: How to distinguish overlapping routes (i.e., LineStrings) based on their direction?

I have a set of routes which are represented by LineStrings in my PostGIS database. These routes represent journeys that people make. I want to come up with routes that (a) overlap, and (b) have the ...
2
votes
0answers
397 views

How to add an offset to a GeoJSON layer in Leaflet?

Using the example GeoJSON tutorial code at leafletjs.com. Change the myLines variable so that the two lines overlap, but run in opposite directions as follows: var myLines = [{ "type": ...
2
votes
0answers
668 views

How to merge linestrings which are connected with each other?

I would like to join linestrings which are connected to each other. The preferred output is a longer linestring based on all joined single linestings! The table that holds my single linestrings is ...
1
vote
0answers
51 views

need to split some linestrings by points

please help me, i'm new in gis 1) i have а table with geom railways, which are multilinestrings (for example there are 2 ways one of which is interrupted, so this way will be multilinestrings ...
1
vote
0answers
32 views

Postgis ST_AsSVG renders a tiny SVG

I am storing information about a person's journey as a linestring. Having recently discovered ST_AsSVG I tried the following query: SELECT ST_AsSVG(path) FROM activities WHERE id = 209 ...
1
vote
0answers
61 views

Progress Bar gets stuck converting Lines to Polygons using QGIS?

I'm trying to convert lines to polygon using QGIS 2.8.1. I use Vector > Geometry Tools > Polygons to Lines. I always get the progress bar stuck on 90%, it can't get to 100%. Could someone ...
1
vote
0answers
57 views

Postgis - st_MakeLine and st_lineLocatePoint

Lets explain, I have 4 points (1,2,3,4), and I need to visit clients (A, B, C, D). So, I need to use st_makeline with (1,2,3,4,3)... Now I have to get % position from A,B,C,D; but in visit order. ...
1
vote
0answers
58 views

Using TIGER/Line shape files, how do I get address coordinates?

I've downloaded addressfeature shapefiles from TIGER/Line on the Census Bureau website. I converted one file to CSV using ogr2ogr. I get the following sample output: ...
1
vote
0answers
109 views

Postgis - Split linestring between point A and B

I need to find the different trajectories between point A and B. In the image is possible to see 2 differents trajectories. The way i use to calculate them is: Found the min time and the max time (in ...
1
vote
0answers
247 views

OpenLayers - Add points at vertices of line while drawing line

I would like to create points while I draw a line on my map in OpenLayers. That is, at each vertices of a line and at the end points there is a shape like a square, circle, or diamond. I have this ...
1
vote
0answers
621 views

Line to Polygon via Polygonizer in QGIS

My question is in the same vein as this one. I'm attempting to convert precipitation lines (Precipitación Media Anual) to a polygon for Mexico in QGIS using the Polygonizer plugin. After running the ...
1
vote
0answers
230 views

Break LINESTRING values in postgis into mutiple LINESTRINGs

Figure A below is the visual representation of what i have in my road data set. Line 1, Line 2, Line 3 in illustration are each represented as 1 row postgis DB inside a geometry column, some of these ...
1
vote
0answers
980 views

How to handle postgresql/postgis geometry type errors in a function?

I have created the following function in PL/SQL to make a polygon from a set of linestrings: CREATE OR REPLACE FUNCTION _myfunction( _fid integer, _rid integer ) RETURNS VOID AS $$ ...
0
votes
0answers
24 views

Creating line-strings from points in MySQL

I am extracting the lat/long information from Geo-tagged images and storing them in MySQL. I want to get a line-string from the points, I looked into the GROUP_CONCAT() function but I am not able to ...
0
votes
0answers
59 views

Drawing lineString in Google Earth API

I am able to draw a Polygon on the Google Earth API which is integrated in my website but i have to draw a lineString. Does anybody can help me? Here is the code i use to draw the polygon: function ...
0
votes
0answers
150 views

google maps api with polyline not displaying lines

I converted shape files into mysql table that has features like LINESTRING and MULTILINESTRING. I am using google maps api ( var shape = new google.maps.Polyline({path: ...
0
votes
0answers
56 views

Drawing Lines Between Postal Codes in Fusion Tables

I'm using Google Fusion Tables and have two columns of corresponding postal codes. Fusion Tables automatically converts postal codes to coordinates (the centroids of each postal code) upon import. ...
0
votes
0answers
69 views

draw coloured LINESTRING over map [.NET (C#) if possible]

I need to render linestring on the map (possibly OSM map) where each pixel (or at least segment) has assigned custom color. In my linestring, each point defining the line has also color definition. ...
0
votes
0answers
174 views

Diferent Line color and Diferent Markers at the same time

i'm about to develop a GIS Track App, but until now, i'm testing with some codes, that i've been creating, but for my project we are going to use XML as data records, today, i am able to create a ...