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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5 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. ...
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1answer
22 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 ...
0
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2answers
22 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 ...
6
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2answers
147 views

What controls the direction of TopoGeometry Linestrings?

In PostGIS, what if anything controls the direction that topogeometry LINESTRINGs will have when converted to geometry? It doesn't appear to be the order in which the edges are listed in the call to ...
2
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1answer
22 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 ...
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0answers
32 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 ...
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0answers
24 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 ...
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2answers
215 views

Counting self intersections of linestring using PostGIS?

Is there a way of using PostgreSQL + PostGIS for finding the number of self intersections in a linestring? I have a linestring that goes forward but in circles, and I need to find the number of times ...
3
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2answers
7k 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.
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1answer
49 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 && ...
2
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1answer
43 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 ...
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1answer
45 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 ...
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0answers
28 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
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4answers
491 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
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0answers
17 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
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0answers
19 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 ...
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1answer
59 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 ...
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1answer
58 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 ...
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0answers
23 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: ...
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3answers
475 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
111 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
266 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
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1answer
38 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 ...
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1answer
718 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 ...
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3answers
344 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: ...
2
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2answers
79 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 ...
6
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1answer
2k views

How can I transform a polygon to a linestring in QGIS?

I have a polygon, imported from a shapefile in QGIS. I would like transform it to a linestring instead so I can save it as a GPX file later. How can I transform a polygon to a linestring in QGIS?
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1answer
140 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 ...
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1answer
53 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.
5
votes
3answers
2k 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 ...
1
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1answer
31 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 ...
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0answers
137 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
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1answer
116 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
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1answer
44 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
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0answers
110 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
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1answer
85 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 ...
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2answers
2k 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 ...
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1answer
52 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 ...
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0answers
77 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
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1answer
37 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.
3
votes
1answer
153 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
84 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 ...
3
votes
2answers
472 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 ...
5
votes
2answers
367 views

Split lines at intersection points

I've got some linestrings covering a road network, and need to split them at the crossroads. Does anybody have any idea on how to do it? I'm using QGIS 2.4, with a Postgis 2.1.3.
3
votes
1answer
78 views

Bounding box of a set of MULTILINESTRINGs PostGIS

I have a PostGIS table with a geometry column (geom) and a type column. The geom column contains only MULTILINESTRINGs and the type column contains tags that tell me what each MULTILINESTRING ...
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1answer
80 views

How to get the LineStrings from a MultiLineString

I was wondering if there is a way I can extract the LineStrings from a MultiLinestring object. What I am really trying to do is look into a MultiLineString and see if I have a certain LineString. I ...
3
votes
1answer
142 views

PostGIS: Get closest point between geometry and Multipoint

I think my question is not that difficult for GIS professionals, but i didn't found an answer to my problem (even not in other questions). Problem: I have given two tables (table1,table2) with Points ...
0
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2answers
89 views

Densify a JTS LINESTRING (add points)

I have a LineString I would like to "soften" in a way that if two coordinates (vertices) in the LineString are very far apart, I want to automatically add some coordinates in between. The line ...
3
votes
1answer
273 views

OpenLayers: How to get *real* centroid of a Line Geometry/Feature?

I have declared a line geometry as: var lineString = new OpenLayers.Geometry.LineString([source,target]); then I am trying to get the centroid of this lineString as lineString.getCentroid(). But ...
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0answers
167 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 ...