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Questions tagged [line]

A set of ordered co-ordinates that represent the shape of geographic features too narrow to be displayed as an area at the given scale (contours, street centrelines, or streams), or linear features with no area (county boundary lines)

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301 views

how to buffer a line with varying distances associated with directional quadrant with open source GIS?

I would like to buffer a set of lines with different distances to the NW, SW, SE, and NE. I have the distances stored in four attribute fields that correspond to the direction the buffer should be ...
4
votes
0answers
73 views

Loop distance point PyQGIS

I have a .shp of lines where I'm able to calculate the sum of segments length but I'm trying to put a point at a given distance in meters. The problem is it puts a point at every segment. When I give ...
4
votes
0answers
67 views

“Merging” 2 layers of LineString with splits at intersections

I would like to "merge" 2 networks of lines and these lines need to be split when they intersect. With pictures it should be clearer : What to do: if a black line intersects a red line, they should ...
3
votes
0answers
67 views

Drawing lines for every row from a table

I would like to make a map showing all the train trips made by different users. I know how to make the difference between a single trip on a traject and many trips by using opacity. For now I have ...
3
votes
0answers
66 views

Given a line find whether another line is along side, N,E,S,W or not

I have a shapefile representing roads (Black) and I need to know whether another line object (Red) is to the side of it. Including the orientation between them, to define whether the Red line lies to ...
3
votes
0answers
96 views

How to undo/redo drawing polyline

I want to draw a custom polyline using mouse click events in an AddIn.Tool project without esri's build-in interfaces eg. Rubberband, IDisplayFeedback or IShapeConstuct. I got problems pushing caches ...
3
votes
0answers
51 views

After dissolving lines, old node/vertex order does not reset, causing issues with chainage

In QGIS, I am trying to dissolve multiple segments of a river feature and then calculate chainage on the resulting single feature. However, it seems like the internal node/vertex order gets preserved ...
3
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0answers
321 views

Create a perpendicular line of points to another line

i have two problems over here. QGIS 1- I need to create a perpendicular line to connect multiple points to multiple lines but these lines have to follow a sequence of column. 2- And these ...
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votes
0answers
494 views

Leaflet: Smooth lines between points without control points?

Goal I want to connect points using a polycurve or curved lines in Leaflet in a scalable way. If possible, without defining control points. Approach I'm using the Leaflet.curve plugin which offers ...
3
votes
0answers
233 views

Reorder Shapefile of lines for consecutive ordering (Assemble Lines into LineString)

I have a Shapefile containing segments of Lines/LineStrings: Unfortunately the order of the DBF attributed table is random. How to reorder the segments so entry #1 in the Shapefile will be "Segment ...
3
votes
0answers
38 views

How to make line id's on continuous order

I have a problem with numbering the line segments. I need to make line segment id's that have letters according to polygon areas (got letters for line segments already) and number according to ...
3
votes
0answers
130 views

How to display a line with fading transparency in qgis?

I have a straight line with two vertices, which I'd like to style. I want the style to be a fading line from start to end, so the transparency is gradually increasing from start to the end of the line....
3
votes
0answers
570 views

Troubleshoot with “Split selected features with selected line from another layer”

I am trying to use the "Split selected features with selected line from another layer" tool from the plugin Digitizing Tools in QGIS. Sometimes, this tool works with my shapefiles but sometimes it ...
3
votes
0answers
936 views

How to join segments of a line in QGIS?

I have lots of different lines composed of hundreds of segments in a Shapefile. I would like to join them spatially where every start (or end) point of a segment correspond exactly (or within a range ...
3
votes
0answers
3k views

QGIS break polyline into line segments

In QGIS (2.14.3.) how do I break polyline features in their consisting (single)line features? I have tried the 'Explode lines' geoprocessing tool, but this destroys the whole polyline into very atomic ...
3
votes
0answers
285 views

Merge line segments by length (in QGIS)

I have a layer containing line segments which are connected by their endpoints (e.g. as within a street network). I'd like to merge (union) polylines within this layer into one feature until following ...
3
votes
0answers
1k views

In ArcMap, when using Add Surface Information, why are all avg_slope values positive?

I've got a polyline shapefile and a LIDAR elevation dataset. I've successfully used Add Surface Information (from 3D Analyst) to calculate the average slope (avg_slope) of each line segment. The ...
3
votes
0answers
1k views

Smoothing Lines in PostGIS

I want to smooth Lines in postgis, to be more specific, I want to smooth road data from OpenStreetMap. Basicly I thought of something like this scenario. This would be a possible road segment. I ...
3
votes
0answers
220 views

Quantifying polyline overlap

I have a set of regions and would like to quantify the degree to which the boundary of these regions are situated on/near rivers. I have turned the regions from polygons to polylines in arcgis 10.1 ...
2
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0answers
55 views

Shortest path between start and end point with many other points in between

Sorry if double post, but I haven't found this specific problem in the search function. I want qgis to show me the shortest path (direct) between many points with each point only is hit once. There is ...
2
votes
0answers
32 views

How to export a single feature (line) from multiple layers and export to individual layers?

I have multiple vector layers representing a time series. Each layer contains many lines each. I want to select a single specific line from each of these these layers and save it to another layer. ...
2
votes
0answers
74 views

Is there a keyboard shortcut to draw a perftectly straight line?

In most programs, when you have a line tool, you can hold control or shift and it will let you draw a perfectly vertical or horizontal line, sometimes it the tool will snap at 90 degree angles. How ...
2
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0answers
147 views

Extend line to specific point

I have a line layer which is cut at the level of the point layer, I want it to be connected at the nearest point while saving the forme ( just adding the missing part the that line without moving it)...
2
votes
0answers
82 views

Clipper: Split polygon layer with line layer - generates empty layer

I am using QGIS 2.14.3 Essen. I wanted to split several polygons with several lines. Both layer are in GK4 coordinate system (used layers generated by: QGIS right-click on layer -> Save as... ) and ...
2
votes
0answers
167 views

split lines into segments without creating new layer in QGIS

How to split line objects into segments/multiple objects based on either polygons or lines without creating a new layer? The problem is clarified in the picture below. I need the green line to be ...
2
votes
0answers
72 views

Converting polyline to polygon without 'Feature to Polygon'

I am attempting to create a script tool to automate some processes at work. Part of this process was to manually cut (using Cut under Editor) a buffer. My approach to this has been to try and split ...
2
votes
0answers
371 views

R coordinates on line nearest to point - multiple points

In R, I have a collection of points (~15,000) within a polygon. For every point, I want to calculate the location on the polygon boundary nearest to the point's location. I'm not bothered about the ...
2
votes
0answers
186 views

R - Spatial Join Between SpatialPoints (GPS coordinates) and SpatialLinesDataFrame

I am working on a university project which combines data science and GIS. We need to find an open-source solution capable of obtaining additional information from a massive GPS coordinates dataset. ...
2
votes
0answers
296 views

QGIS: Select Lines within a polygon

I would like to select all lines within a polygon. I tried to do that with the clip-function, but it didn't work out (the resulting layer was empty). Do I have to select a particular setting before ...
2
votes
0answers
30 views

Why do new lines appear when transforming polygon into lines?

I'm quite new to QGIS, and I want to do something fairly simple, but I found something strange in my data. I want to transform polygons into lines, so I can apply the buffer function afterwards to ...
2
votes
0answers
154 views

Shortest path creation between two lines

I've a raster of temperature of a river, I'd like to extract values horizontally, so from bank to bank, shortest path. so basically extract pixel values along the red lines in the schema I did. What ...
2
votes
0answers
112 views

Determine percentage of parallelism of two parallel lines in QGIS/python

I'm trying to match some lines to each other and join attributes proportionally. Have a look at the image where S1 can appear in both A1 and A2. Let's say 30% of S1 is parallel to A1, and 15% of S1 is ...
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0answers
93 views

Railways usage - How to assign values to part of existing lines?

I am conducting a project about rail accessibility/capacity, working with railways/stations downloaded in R with Overpass. Manually I computed the number of trains for each lines and I would like to ...
2
votes
0answers
129 views

Split line into the different lengths from attribute table data

Is it possible in QGIS to split one line in one direction into multiple segments of varying length which I have in the attribute table? For example: overall line is 10 m long, in table I have data: 1....
2
votes
0answers
75 views

Combining points and polygons in Qgis

I´m trying to create a map that can be loaded into the program CityEngine as a shapefile. To create this map I have an excel spreadsheet that includes locations, in longitude and Lattitude, and ...
2
votes
0answers
127 views

How to measure orthogonal distance of line from point in QGIS?

As I am fairly new to QGIS I'm seeking your help. I'm trying to measure the distance between points in a point Layer P and the end of lines in a line layer L. In L there are two categories (attributes)...
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votes
0answers
68 views

How to count near intersecting polylines and merge them?

I have a dataset with several polylines created by GPS points of car trips. I am trying to create a simple heatmap where roads with more traffic (where polylines intersect) get darker. I already ...
2
votes
0answers
1k views

Algorithm to simplify a Polygon/Series of Points to a given number of Points

I have a polygon (or let's call it just a series of points). I want to simplify it (reduce the amount of points) to a given number of points. Currently I use Douglas Peucker and try to guess the ...
2
votes
0answers
463 views

Showing marker upfront in OpenLayers 3 while drawing polyline?

I am drawing the polylines on the map and displaying few marker as well which is working fine but when the polyline is drawn marker is above the line I wanted to know how to show the marker upfront ...
2
votes
0answers
120 views

Split Polyline QGIS - Too Many Resultant Features

I'm trying to split a single polyline into 2 polylines (I have lines that loop back on themselves, and I need to split each one into two lines: one for going, and one for coming back). When I use ...
2
votes
0answers
217 views

Equal distance points on polylines

In QGIS 2.10.1 I want to create a point layer out of my polyline shapefile and all the points shall have a fixed distance (in meters) while I use WGS84 as coordinate system. So what do I use for this? ...
2
votes
0answers
248 views

Connect two contour lines with calculated line length

Is it possible to make a plugin for QGIS like PEGGER for arcview 3.2? Problem is, how to make path over contour lines with a gradient in percent? Formula is: K= e*100/G*M ; K=10*100/0.08*10000=1.25m ...
2
votes
0answers
123 views

How to measure similarity of approximately congruent polylines

My initial question was posted here. The answer of whuber provides a nice solution for the case when polylines are congruent. However, the problem is that my polylines are approximately congruent (...
2
votes
0answers
361 views

nominatim api for long streets

I'm using the Nominatim API in geojson method to retrieve streets poly line. For short streets I have no issue and the results are good. However for long streets the data I'm getting back in the ...
2
votes
0answers
419 views

How do I accurately measure a gps track over a long distance?

I am measuring the length of the Continental Divide Trail that goes from the Mexican border to the Canadian border. I have a .gpx file of the entire route in NAD83 with tracks about every 50 meters. I'...
2
votes
0answers
3k views

Find Average Elevation - ArcGIS Desktop

I am working with 2 shapefiles. One contains the boundaries of a city, the other contains polylines representing the topographic features of the area. Essentially, the polylines make a topographic map....
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vote
0answers
29 views

Copying features certain number of times between layers in QGIS

On the image below, there are two layers showing the transportation network Red | current | only important objects | geometry repeats/overlaps Blue | new | required and other objects | ...
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0answers
19 views

Point to line - Qwater model

I'm using EPANET in QGIS (extension QWater). I have different layers : pipe network (line vector) household (point vector) Firstly, I'd like to connect household automatically and perpendicularly to ...
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vote
0answers
17 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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vote
0answers
35 views

ArcGIS polyline dangling endpoints count

Is there a way for count the number of dangling endpoints of a polyline? I need that because I would like to define a feature complexity parameter. For example, on the image below, the number of ...