Questions tagged [linestring]

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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32 views

QGIS splits line feature at all intersections? [duplicate]

I have a long GPS track that I've converted to a shape file. I need to divide it into segments. The first time I use the "split features" tool, it makes a cut where I draw my line, but also splits the ...
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1answer
44 views

QGIS Linestring rendering curves between vertex

I'm sure I hit a setting somewhere, but now I can't fix it. When a linestring shp file is rendered in QGIS it adds curves between my verticies... I want straight lines. How do I turn this off? In ...
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1answer
63 views

PostgreSQL: Copy the line segment together in another table without copying the intersection with another line segment

Presently these linesegments are in different rows but in the same table and numbers shown in the image are the ids of respective linestrings. I want to copy linesegment 350, 333, 352,4,.. in one ...
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1answer
53 views

Measuring / calculating curvature of linestring using QGIS?

How can I measure/calculate the curvature of a linestring? I need just a boolean value: is curved or is not curved. At the moment, I don't find a working strategy for that.
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15 views

How can I smooth LineString coordinates with 1D Gaussian Filter?

I'm trying to smooth a LineString through 1D Gaussian Smoothing and I'm having a doubt on the steps required to implement it, regardless of programming language. I couldn't find by myself anything ...
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1answer
61 views

Converting lat long strings to xy linestrings [closed]

In PostGIS, I have a dataset with road segments including a column with coordinates for the various segments. The coordinates are in a lat-long format and the data type of the column is character ...
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20 views

Is there a standard way to apply different field values to linestring vertices?

In QGIS I have several 3D points that I am creating a linestring from and each point could have a different value in one of the fields like "type". I want to somehow create the linestring and be able ...
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31 views

Behaviour ST_Intersection of 3D LINESTRING and 3D POLYGON - Z value with GEOS backend

I do not quite understand the behaviour of ST_Intersection applied to 3D geomerties when using the GEOS backend. Take this example: SELECT ST_AsText(ST_Intersection('POLYGON((1 1 1, 6 1 3, 6 4 3, 1 4 ...
3
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1answer
74 views

Converting point into line using QGIS

I have a set of points with datatype as geometry(MultiPoint, 32643), I want each point to be converted in short line segments. The purpose of doing this is to use "split by lines" tool in QGIS which ...
2
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1answer
103 views

QGIS SAGA split lines at points creates redundant lines

I have 2 projected (ESPG 2039) layers of roads and points (bus stops and junctions). I snapped the points to the roads layer and this is how it looks: I then try yo use Saga Split lines by points to ...
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29 views

“bending” lines to a predetermined shape

I have a dataset with AIS-transponder information. A AIS-transponder is a digital system onboard a ship that sends/receives information to/from the vessels within range of the VHF transceiver in a ...
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1answer
128 views

Create a line string from street geometry

I'm currently facing some hard times trying to create a simplified line from a street geometry. The data that I'm currently using comes from OpenStreetMap, using osm2pgsql.(Which means PostGIS, but I'...
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27 views

Check point in line segment not accurate in Shapely

I use Shapely and I've run into an issue where I can find the intersection of two lines. However once I have the intersection point, I don't seem to be able and cross-reference that it belongs in both ...
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1answer
122 views

Getting geohash of LINESTRING in PostGIS?

I have some LINESTRING in PostGIS. LINESTRING(104.011 30.637,104.014 30.638,104.022 30.640,104.026 30.645) LINESTRING(104.022 30.666,104.031 30.659) LINESTRING(104.044 30.655,104.056 30.655) I ...
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1answer
157 views

Add Line Layer from PostGIS to Leaflet

I have a line layer in PostGIS that I would like to add to a Leaflet map. I have the PHP setup, but I can't seem to get the Javascript correct. I know my issue is converting the line to geoJSON. The ...
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3answers
122 views

Can I reorder the coordinates of a line when importing into QGIS a WKT linestring?

I managed to import a csv file containing lines in QGIS but unfortunately the x y aren't in the correct order. that is, the csv has a field where there is a sequence of lat (y), lon (x), while qgis ...
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1answer
50 views

Converting CSV with LineString into shapefile using ArcGIS Desktop?

I have a CSV which I've imported into ArcGIS Desktop, and it contains a Linestring column. How do I convert it into a shapefile? Example of what one of the fields contain below: [[51.53878768021,...
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59 views

Shapefile lines disappear, but data remains

I'm working in QGIS 3.4 on a line type shapefile layer with +/-5000 records. I made an edit to the start/end nodes of a couple of lines to move them to a point node from another layer; then when I ...
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41 views

Geospark - Creating LineStringRDD from coordinates extracted from the sides of each polygon in a PolygonRDD

I am using geospark 1.1.3 with scala and I am trying to split into lines a polygon shapefile dataset which contains 189 polygons. I am expecting to get each side of each polygon as a LineString, ...
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50 views

Mark Dangle Error for linestring

I will create buffer for 5 meter in start point of line string, If any other line string is within the buffer but not snapped then to mark as the startpoint as dangle error.I have attached the sample ...
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62 views

Matching streets in two line datasets with PostGIS or QGIS?

Explanation: I have 2 tables on PostgreSQL, one table named 'city' that have linestrings wich represents streets from a city (using QGIS I downloaded OpenStreetMaps data and imported to PostgreSQL ...
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35 views

Segmentation of a line based on several overlapping lines within the first line

I stumbled over a problem which I can't figure out myself so maybe you can help me.. I have a line going from 0 to 100% of its length. On this line I have 1:n lines with different information and ...
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1answer
152 views

OpenLayers Linestring does not draw straight images

My problem:Add image along the LineString My problem has been solved here, but when I add a 32x32 image and I draw between two points, the images in the line don't go straight and there's a slight ...
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39 views

Stop detection on a dataset of (id,geometry points,timestamp) to be transformed into meaningful trajectories

My pretty large dataset consists of AIS transmitted messages. I load the dataset to a table in my db. Among other columns in this table, there are a longitude and a latitude column. I already ...
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56 views

How can I calculate the “average” or “median” result between a number of MultiLine Strings?

So I have a number (let's say 12) of multiline strings representing something that changes over time, like forest borders or shorelines. I want to create a single line that is the result of the ...
2
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1answer
746 views

Add image along the LineString

I am wondering how to place images on a line. For example, instead of a dotted or dashed line. I could include a symbol of a cloud a character (e.g. |) repeated along the line. it cannot show the ...
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38 views

How to add date to point?

I have a lot of points with a GPS tracker and I need to simplify them. I create view (location_view) in PostgreSQL (with PostGIS): SELECT location.id, location.added, location.latitude, ...
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0answers
85 views

Change from LineString to MultiLineString when saving layer edits in QGIS

In QGIS, when a user creates a new single part line in an open editing session for a “Multi-Line” SpatiaLite dataset, the QGIS data type is initially a “LineString”. But, when the user commits the ...
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2answers
65 views

PostGIS MakeLine issue

I am using GPS coordinates and I am trying to create lines (routes) from lon,lat. I create a geography column from my point and then I create the line as following: ST_MakeLine(point_geom order by ...
2
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1answer
290 views

Slow PostGIS line intersection even with indexes

I have line data contained in different graphs. Querying data over multiple graphs and using st_intersects results in slow queries. All lines are represented as geometry(LineString). I am querying ...
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0answers
100 views

Cluster LineStrings using HDBSCAN?

I am trying to cluster a set of LineStrings (made out of lat/lon Points) with the help of HDBSCAN (using the "haversine" metric). The objective is to define the most "usual" path. I have only managed ...
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0answers
55 views

SumLineLengths in QGIS 3.2 not working?

I'm trying to use the Vector > Analysis Tools > Sum Line Lengths in QGIS version 3.2.3-Bonn. I'm inputting a ploygon (Multi Polygon) and a Lines (MultiLineString) shape files. I'm hoping to get the ...
3
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1answer
131 views

Calculate polygon main dircetion and create line from it - POSTGIS

I would like to find out the orientation of a polygon and create a line of that direction. See image below.
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1answer
52 views

Lines overlaping in same layer - PostGIS

I have lines overlapping in one layer as in image below. How do I delete one of these lines and leave the other one in the dataset?
3
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1answer
166 views

Select only lines that touch both sides of polygon - PostGIS

I want to select lines that only touch both sides of a polygon. Is there a function in postgis that can do this? See image below. I only want to select lines from the circle on the left where the line ...
2
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1answer
79 views

Determining direction of traffic in road network?

I'm working with road segments as LineStrings in GeoPandas, for each segment I would like to determine the direction of travel (they drive on the right). This information is not encoded, how can I ...
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0answers
71 views

Using Shapely's ops.snap? [closed]

I have two polylines whose endpoints are near to each other, but do not overlap. I've put them into this shapefile. I want to use shapely's ops.snap() to snap their endpoints, but it's not working as ...
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2answers
179 views

Shapely floating problems with split()

Based on the answer of sgillies I want to use Shapely's interpolate() to find the points at which to split. But I experience that split() is sensitive to the points being precisely on the geometry you ...
1
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1answer
60 views

Osm2pgsql - Lines instead of polygons that represent buildings

So I am using a PostgreSQL database with the PostGIS extension to extract building data with addresses from osm data. I just discovered that in my dataset, imported with osm2pgsql of the german city ...
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1answer
69 views

Query to return closest LineString given a Point [duplicate]

I have a road lines data in a table with field roads(id SERIAL ,the_line geometry(LineString,4326)) suppose an accident occurs in a middle or at any location in that waterline i want to stop the ...
0
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1answer
82 views

r - turn off automatic ordering of linestrings when applying sf::st_intersection

This question is about how while using sf::st_intersection on a LINESTRING and a set of POLYGONs to get several LINESTRINGs in the CORRECT order. sf::st_intersection automatically orders the newly ...
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0answers
60 views

Breaking LineString into MultilineString group by distance between two points and it's time

This is line string of my geometry column that created by postgis and shown in qgis: This is multiline string like above: I am new on gis and How can i do break line and convert it into multiline? I ...
2
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1answer
367 views

Sort a geopandas dataframe by location

I have a geopandas DataFrame (created from a shapefile) which represents the course of a public transport vessel. Exemplary DataFrame: | oid | geometry | |-----|---------------------| | ...
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0answers
29 views

Processing tool to fill all voids within a lines layer

I'm trying to convert a lines layer from Ordnance Survey which is made up of field boundaries, river banks, woodland boundaries and houses etc into a polygon layer, but only 'polygonise' the fields. ...
2
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1answer
100 views

Is there a way to calculate length of linestring from one point to another?

If I have one linestring and coordinates of two points on that linestring, what is the easiest way to calculate not shortest distance from those two points, but distance over the given road (given ...
3
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1answer
788 views

Access vertices of a line in Python

Given a shapely.geometry.linestring: How do you access single vertices using Python?
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1answer
168 views

Direction of two lines (turn right or left)

There are two connected lines (EPSG:4326 line1, line2). When the direction of the two lines is from line1 to line2, I want to do a calculation to determine whether the direction is left or right.
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0answers
308 views

Intersect a linestring with a collection of polygons in Shapely

I have a LineString that represents a trajectory and a Python list of Polygons that represent crossroads. I would like to insert new points into the LineString wherever it crosses any of the polygons, ...
1
vote
1answer
296 views

Convert a linestring into a closed polygon when the points are not in order

How can I convert an open linestring into a closed polygon, but when the points are not in order? Here is the easy case, when the points are in order (from an sf vignette): library(sf) #> Linking ...
1
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1answer
31 views

Locating geometries within a polygon/area

I have a postgis database table of boundary data which is made up of LineString geometry's, what I would like to do is create a query that will return only the rows that contain a LineString geometry ...