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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2answers
22 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 ...
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2answers
183 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: ...
3
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1answer
284 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 ...
3
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1answer
81 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 ...
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1answer
22 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 ...
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1answer
64 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 ...
3
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0answers
162 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
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0answers
370 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 ...
3
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0answers
699 views

leaflet - Drawing line following the road

Short version: What I wish to be able to do is drawing a polyline along part of a road. In that way marking certain houses, along this road. Long Version: I have several houses that I wish to mark ...
2
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0answers
61 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 ...
2
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0answers
108 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": ...
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0answers
11 views

Merge multiple linestring features into a single multilinestring

Using QGis or ogr2ogr how do I convert a vector file containing multiple linestrings features into a single multilinestring feature? At the moment I've been doing this manually by converting the data ...
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0answers
91 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 ...
1
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0answers
462 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
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0answers
356 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 ...
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0answers
166 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 ...
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0answers
513 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 $$ ...
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0answers
16 views

Offset WGS84 linestring based on pixel values

I would like to split up some roads based on their driving direction. For this, I need to offset the roads 2 pixels to the right, in the direction of the linestring. I have the coordinates in WGS84 ...
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0answers
14 views

Know if MBR contains any POINT of LINESTRING

I have a table with a Geometry column. This column only has LINESTRING. This LINESTRING only has two POINTS. If i have a MBR, i need to know which of LINESTRING of my Table has some of its POINTS ...
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0answers
30 views

Multiline String to Linestring conversion

I have road network table which is multilinestring.I was trying to convert this file to Linestring using the following query ALTER TABLE multiline ALTER COLUMN the_geom TYPE geometry(linestring,4030) ...
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0answers
63 views

Maximum number of points in a linestring?

I have a database (in Postgres/PostGIS) of GPS points recorded all over a rail network. The only data available is the lat/long coords of each point (no timestamps, links between points, or anything ...
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0answers
161 views

Computing percentage of similarity between two line strings using python shapely

I'm quite new to shapely, been tinkering with it and I have a necessity to compare two line strings and see what percentage of them overlap. The geographic coordinates come from two different systems. ...
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0answers
32 views

How to split a feature using GDAL

I want a feature to be cut into 2 or more based on deviation of a segment i.e., the angle between 2 successive segments. At places, I may also require to merge 2 or more features.
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0answers
120 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 ...