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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36 views

PostgreSQL create line from points

How do i create a linestring from points sort by date in PostgreSQL? I tried: SELECT observations.id, ST_MakeLine(observations.geom ORDER BY observations.date) AS newgeom FROM observations ...
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22 views

How to convert multilinestring to linestring in WKT field of a CSV? [closed]

I previously developed a workflow in which I would digitize line segments in a shapefile that would ultimately be converted to a CSV, and the geometry stored in a WKT field. When this workflow was ...
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1answer
32 views

Copy/pasting QGIS features between two layers with linestringZ() geometry gives linestring()

I'm puzzled: when I copy-paste a feature with linestringz() geometry to another layer I get linestring() and the elevation attribute is lost. Although when I paste to a text editor I see a linestringz(...
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1answer
247 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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1answer
12 views

Mapbox: Multilinestring Z, stand on the background

I added to Mapbox, a 3D not extruded object by geojson: a Linestring Z. But it's stand on the background. So: I'ts possible to put this object at the height that is defined?
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1answer
23 views

Batch open GeoJSON LineString from files with multiple features

I want to open multiple GeoJSON files, each have Points and LineStrings - I only want the LineStrings. I want to open potentially 1000s of files so don't want the popup asking if I want Points or ...
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17 views

Combining Multiples Linestrings into Polygon (Turf.js)

My main goal is to combine linestrings into a polygon. Is there a way to accomplish this using a library like Turf.js, or are there any geometrical rules to follow ? I Tried building the concave hull ...
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9 views

Merging overlapping GeoJSON LineStrings (Tippecanoe) and add visualization

I would like to merge overlapping GeoJSON LineStrings and visually style merged LineString. I have a database of GeoJSON LineStrings which represent routes people drove. I would like to visualize ...
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1answer
54 views

Extract borders from country polygons

I'm trying to convert a polygon GeoJSON of countries into a line layer that contains only the borders. It should not contain the edges of the polygons that border the ocean (in my polygon dataset, ...
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0answers
22 views

Extend LineString on map zoom [closed]

In OpenLayers 5, I have some LineString that represent the streets. Now I want that when the map is zoomed also the LineString should be zooomed. For example in the following image, I have two ...
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1answer
60 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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55 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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44 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 ...
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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 ...
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1answer
55 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 ...
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1answer
180 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 ...
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48 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 ...
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1answer
101 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
270 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 ...
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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 ...
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1answer
56 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
10k 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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75 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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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 ...
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1answer
92 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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2answers
268 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 ...
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1answer
77 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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21 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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0answers
46 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 ...
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1answer
85 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 ...
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1answer
166 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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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 ...
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0answers
719 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 ...
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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
153 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
36 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
182 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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3answers
130 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
93 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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0answers
68 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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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 ...
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0answers
66 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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1answer
158 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
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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55 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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79 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
36 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
159 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
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1answer
975 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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0answers
65 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 ...