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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2
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1answer
36 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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0answers
48 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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0answers
37 views

AGOL REST API: Why do linestrings auto-convert to multilinestrings w/ 0 z elevation?

I'm using the ArcGIS Online REST API to add/delete features from a 3D web layer. I'm able to POST linestrings to the layer. But, seemingly randomly, some (not all) of the linestrings get converted to ...
2
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1answer
32 views

Controlling line width at different points in QGIS [closed]

I have vector data for rivers including their width at various points. From what I have seen so far, QGIS 3.8 can set the line width only per linestring, no per segment. Is it possible (maybe with a ...
1
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1answer
46 views

Line at map scale that do not vanish when zoomed out? (QGIS 3.8)

I'm drawing rivers and roads as linestrings with width set in map units from an attribute. When zooming out, of course they vanish quickly, because 10, 20 or 100m is less than a pixel at 1:100,000 ...
2
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1answer
179 views

Using forceToLineString() with GDAL and Python?

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 2),(0 2,0 3,0 4)) ==> LINESTRING (0 0,0 1,0 2,0 3,0 4) I ...
3
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0answers
42 views

Calculate weighted azimuth/bearing of a line

Given the line LINESTRING(-9.086532643219698 -7.939337106873815,-1.396102955719698 -0.9775148048290135,-0.780868580719698 -0.7138718839794582,-0.077743580719698 -0.6699297767574899,0.581436106780302 ...
1
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1answer
98 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 ...
0
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1answer
259 views

Getting width of road segment given its end points using Leaflet?

I want to highlight a road segment on a Leaflet Map. I have the coordinates of the end point of the road segment, so could plot it as a linestring. But the problem is how can I get the width of the ...
2
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0answers
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 ...
4
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1answer
52 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 ...
8
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1answer
9k views

Turning GeoDataFrame of x,y coordinates into Linestrings using GROUPBY?

I have a dataframe of X,Y coordinates that represent points along the paths taken by several different entities. Pseudo-data here, but it is roughly of the form: entity_id lat lon time 1001 ...
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0answers
74 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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0answers
59 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 ...
2
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1answer
79 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.
1
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2answers
241 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 ...
0
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1answer
70 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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0answers
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 ...
2
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0answers
42 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
80 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 ...
4
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1answer
203 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 ...
2
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1answer
144 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 ...
6
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1answer
2k views

Using makeline() function for more than 2 points in spatialite?

Is it possible to use makeline() function to make linestring geometries in spatialite for connecting more than 2 sequence points? Suppose I have four sequence points P1, P2, P3, P4. Or are there any ...
10
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0answers
702 views

Simplify the straight sections of (multi)Linestring in PostgreSQL/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
32 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 ...
5
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1answer
145 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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0answers
31 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 ...
0
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1answer
162 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 ...
4
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3answers
126 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 ...
0
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1answer
76 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,...
2
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0answers
65 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 ...
2
votes
1answer
1k views

Clustering similar lines in PostGIS?

In PostGIS I have a large database of linestrings which I have obtained using ST_makeline function. I would like to cluster similar lines based on where the lines start and end. Here is an example ...
0
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0answers
56 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, ...
3
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1answer
154 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.
13
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1answer
3k views

Detecting if point is on left or right side of 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 ...
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0answers
52 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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0answers
77 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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0answers
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 ...
0
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1answer
158 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 ...
2
votes
1answer
909 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 ...
1
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0answers
64 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 ...
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0answers
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, ...
4
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0answers
104 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 ...
2
votes
2answers
82 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
votes
1answer
385 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
vote
3answers
6k views

Convert MultiLineString to LineString using QGIS

In QGIS, I've tried the following options to convert my GeoJSON file from MultiLineString to one or multiple LineStrings (translating the Danish version): Vector -> Geometry Tools -> Polygons to ...
2
votes
2answers
140 views

Is it possible to adjust the length of a GeoJSON LineString?

Let's say I have the following GeoJSON: { "type": "FeatureCollection", "features": [{ "type": "Feature", "properties": {}, "geometry": { "...
2
votes
1answer
331 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 ...
1
vote
0answers
121 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 ...
13
votes
1answer
18k views

Transforming polygon to 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?