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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2
votes
3answers
95 views

How to remove identical lines from layer in QGIS?

I converted polygon layer to line layer using "Polygons to Lines" tool. Then I used "Split" function of the Networks plugin. What I need to do next is to remove identical lines that were shared ...
5
votes
0answers
249 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 ...
3
votes
2answers
368 views

How to recalculate the the length of a geography linestring from nearby geography point in POSTGIS?

I have a geography type linestring *route_geography geography(LineString,4326)*, its a route from point A to point B. Now I have a point C near that line. I want to find the nearest point on that line,...
2
votes
1answer
95 views

How to export a CSV with lat lon WKT from a layer which is not in WGS84?

I want to extract a csv with lat and lon coordinates so I select -- Geometry AS_WKT but when the csv is created I see this LINESTRING (277054.55782319931 198725.03588318737,277052.43701817648 198727....
0
votes
0answers
85 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
249 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: this.ll_(geometry.coordinates)})...
0
votes
1answer
229 views

Multipolygon From Multilinestring PostGis

I have been looking for a answer for days. I dont even know if its possible. Tried: ST_AsGeoJson(ST_MakePolygon(ST_transform(geom,4326))) ERROR: Shell is not a line ST_Polygonize(ST_LineMerge(...
1
vote
0answers
67 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 ...
4
votes
1answer
333 views

How to detect if point is on the left or right side of the line in PostGIS

I have a linestring table and a point table in postgis. I know the closest line to any given point. What I need to know is on which "side" of that line is the point. I guess I have to do that by ...
0
votes
0answers
114 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. ...
1
vote
0answers
52 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 ...
2
votes
0answers
34 views

match noisy GPS data to closest linestring in road network [duplicate]

I have some noisy GPS data(Points) that they are not exactly on the road because of the noise. But I want to match them to the closest road linestrings. How to do this in PostgreSQL? Data: ...
0
votes
1answer
125 views

Spatial query ST_CONTAINS returns empty result

I want to create a database view in Postgres/PostGIS which returns a subset of the points stored in another table called locations. The subset is defined by an area stored in yet another table called ...
3
votes
2answers
227 views

Merging linestrings in QGIS using PostgreSQL and PostGIS

I've to merge all linestrings from a PostgreSQL table "river" where not more than two start-/endpoints are overlapping. In the illustration below I use a "M" to mark all linestrings that needs to be ...
4
votes
1answer
2k views

How to create polyline of varying distance from origin point using azimuth?

I am looking for a Python script that does the following: Uses a point (from a point shapefile) as the origin. Creates about 3 km line from point Based on an azimuth provided in the original point ...
2
votes
3answers
378 views

postgis linestring segmentation in 4326

How can I divide a single postgis linestring with SRID 4326 into segments (preferably an array of linestrings) with no segment longer than a given distance? I've tried st_segmentize(), but it spits ...
3
votes
2answers
196 views

Remove specific points from linestring postgis

I am working with a data set that has been using the (0 0) point to pad any points that were missing when the linestring was created. So now the query SELECT id, route as line FROM trips ...
2
votes
4answers
183 views

How to determine if two points are on the same side of a LineString?

I have two points, A and B, and a line string L. A line string is formed by a sequence of points such that consecutive points are joined by a straight line. This is the same as a LineString in Geos - ...
2
votes
1answer
203 views

How to individually label points in Openlayers linestring?

I want to display some text below each point on a linestring with Openlayers. The text would include, for example, the coordinates of the point, plus some other information. I have managed to add a ...
2
votes
1answer
77 views

Algorithm to remove Loops from a Line-String

I am using a third-party API to acquire a linestring representing a route. Occasionally, this API (which I will not name, here) returns a linestring that contains loops. Logically, this makes no sense....
1
vote
0answers
97 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 ...
4
votes
2answers
11k views

Creating line with specific length using ArcGIS Desktop?

How can I create a line in ArcGIS 9.3 to a specific length? I click once to start the line where I want it, and then I want it to be, say 10 Meters in length ... Similar to AutoCAD.
2
votes
1answer
133 views

ST_LineMerge doesn't return LineString

I want to create a LINESTRING from a MULTILINESTRING. However in the following case ST_MultiLineString is returned: Select ST_GeometryType(ST_LineMerge(ST_AsText(' MULTILINESTRING( (-70.52570888 -33....
1
vote
1answer
84 views

What is the best way to get two points along the line in both directions using postgis?

I have a point on a linestring geometry (found by an intersection). What is the best way to get two points along the line in both directions using postgis? It does not really matter if the points ...
1
vote
0answers
72 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. ...
3
votes
4answers
593 views

Redistribute linestring vertices to specified distance

I use a groundwater model program called GMS, and it has a very useful function "Redistribute vertices" (more info). I use this function all the time to both simplify and provide regular spacings ...
2
votes
0answers
52 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 ...
3
votes
0answers
71 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 ...
0
votes
1answer
128 views

QSpatiaLite Plugin: LINESTRINGZ(x y z, …) supported?

I get an error when trying to import this query as a spatial table in QGIS: select geomFromText('LINESTRING Z(13.091464 47.061328 2597, 13.092059 47.061287 2580)') as geometry 'The result can't ...
1
vote
3answers
1k views

Cannot st_linemerge a multilinestring because its not properly ordered

i have a MultiLineString which i created by using st_union in many steps. Each of them are connected to each other according to their points, but the order is not correct. So ST_LineMerge is not able ...
3
votes
2answers
159 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 ...
3
votes
1answer
324 views

Polyline “breakage” calculation in MapInfo?

I am a novice MapInfo user, with a basic to moderate knowledge of queries and SQL. My work entails doing risk assessments for shipping traffic based on AIS-tracks (radio-based vessel information ...
0
votes
1answer
94 views

Postgis: Conflation of two vector layers into a single layer

If I have table A that I consider to be definitive and table B that may have some elements missing from table B but also has geometries that are "close" to those in A that I want to ignore. How could ...
1
vote
1answer
930 views

Converting LinestringM to Polygon PostGIS

I'm working with PostGIS and plotting polygons on a Google Earth plugin. I've found a few examples via Google on how to convert a LinestringM to a Polygon for rendering, but none of them, including ...
1
vote
3answers
545 views

Create multi-line from point in PostGIS

I'm working on an old table where polygons are stored as points. Now, I want to migrate these points to PostGIS and store them as polygons (or multi-polygons). The table structure is as follows: ...
1
vote
1answer
351 views

PostGIS - Intersects feature to split into linestring

I would like to know if it's possible to intersect feature datasets (multipolygon, polygon, multilinestring and linestring) to get a result as a set of linestrings being split at each intersection ...
1
vote
1answer
114 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.
1
vote
1answer
72 views

How to use gdal's “forceToLineString()” with Python

I'm working with Python and GDAL and I'm quite new to this ^^ For my script I'm looking for a method to convert a MultiLineString into a simple LineString. Example: MULTILINESTRING ((0 0,0 1),(0 1,0 ...
3
votes
0answers
217 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
1
vote
1answer
386 views

How to find a point on linestring and in a range of 10 meter

i have a linestring which is show in diagram and i have a point which is some time on the linestring or out of linestring but in range which is red line and some time its is out of range so how can i ...
1
vote
1answer
61 views

Index to speed up ST_HausdorffDistance?

When comparing similarity of linestrings with ST_HausdorffDistance (or another type of similarity function), is there a way to use an index to speed up the search for similar linestrings?
2
votes
0answers
322 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) ...
0
votes
1answer
195 views

Check if point is near a linestring Spatialite

I have a LINESTRING made of two points start point and end point in spatialite. UPDATE points SET road_geometry = GeomFromText('LINESTRING(24.889142 67.196188, 24.889673 67.196579)',4326) where name=...
3
votes
2answers
5k views

How to find nearest line from point using PostGIS?

I have a table of Roads in PostGIS which geometry is "geometry(MultiLineString,4326)". Its attribute are gid osm_id name ref type oneway bridge maxspeed geom Now i want to know ...
1
vote
1answer
74 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
0answers
130 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
1answer
56 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.
4
votes
1answer
314 views

Showing Linestring from SQL statement with CartoDB

I have cartodb sql statement to return what polygons are intersected by a linestring, but I'd like to have the linestring visualized over the polygons on the results. Also not add the linestring to ...
3
votes
1answer
109 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 ...
4
votes
2answers
970 views

In PostGIS, how do I merge a multilinestring into a single linestring, keeping the pieces in proper order?

I have a multilinestring made up of several pieces, some of which are facing the wrong direction. (Accessible here: http://pastebin.com/89Zcixv5 ) I think what I'm looking for is some utilization of ...