A digital map feature that represents a place or thing that has length but not area at a given scale. A polyline feature may have one or more parts.

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9
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5answers
1k views

Measuring straightness of a curve segment (represented as a polyline)

I'm working on an automatic elevation contour labeling algorithm and one of the factors that I want to take into account when deciding the positions of labels is how "straight" a particular segment of ...
8
votes
6answers
3k views

Get a point on a polyline from end points given distance along poly line

I have start point and end point of a polyline. How can I get a point on that polyline from end points specified by the given distance. How can I get this by using arcpy provided that this script ...
8
votes
2answers
982 views

How can I create random points along a polyline in QGIS?

I am trying to create random points along a polyline shapefile in QGIS. Basically, like the 'random points' tool in 'research tools' but for polylines instead of polygons. I have tried converting ...
7
votes
1answer
345 views

How to create arrows lines automatically on ArcGIS, for a thematic map of directed flux?

I need to create a Map with the Import and Export Flux between countries. I have the needed data in my table. But I wish to know if there is any tool or extension which allow me to create those ...
7
votes
4answers
2k views

How to close multipart polyline gaps in ArcMap

I have a multiple multipart contour lines that originally came from CAD drawing. I converted these into a polyline shapefile in ArcGIS. The issue I have is with gap in each contour lines that are ...
6
votes
5answers
2k views

How to create points in a specified distance along the line in QGIS?

I want to use QGIS creating points along the line, but in specified distance. I found two GRASS tools in SEXTANTE Toolbox: v.to.points v.segment I tried v.to.points, setting the maximum distance ...
6
votes
1answer
196 views

How can I transform polylines into points every n metres in PostGIS?

Question in pretty much the same as this, but I need to use PostGIS. I have a number of polylines, and want to trasform them into points every n metres along these lines. edit: Thanks a lot to ...
6
votes
2answers
111 views

Finding lines in point patterns?

I have a point pattern (see below) in which I assume to find "significant" lines of points. However, I did not find any method that is integrated in a GIS or in R that searches for such line pattern ...
6
votes
2answers
374 views

How to calculate tortuosity of a coastline?

I would like to calculate the tortuosity (or fractal dimension) of a coastline within a 1km buffer surrounding a point on that coastline. I have hundreds of points and therefore need a tool or scripts ...
6
votes
1answer
129 views

Split polylines in ramps

I have a shapefile (polylines) of some roads and I want to divide the roads in ramps. Ramp = a piece of the road delimited by the top of a hill and a valley. So, pretending that you're driving in ...
6
votes
2answers
877 views

QGIS or Postgis - How to split polylines with a point layer?

In QGIS, I would like to split the polylines in a layer loaded in the workspace with the points in another loaded layer. If a point intersects a polyline, this polyline should be transformed into two ...
6
votes
1answer
522 views

Splitting polylines according to coincident (or touching) points with other polylines?

The question is unfortunately not answered yet. I'm looking for a method or python script to split polylines according to coincident points with other polylines, but avoid splitting the ones which ...
5
votes
2answers
1k views

Leaflet Polyline with custom fill pattern

I'm drawing Lines with leaflet.js an have to create custom styled polylines. So i got various image files which should be like a repeated background image in HTML. So is it possible to give a drawn ...
5
votes
1answer
401 views

ArcGIS Symbology Transparency

Using ArcGIS 10.1, I am interested in symbolizing a series of polylines to generate a pseudo-heatmap like one of the answers to this question. The essence of the solution idea is to symbolize each ...
4
votes
2answers
350 views

How to draw lines from two points in a CSV?

I have a CSV file where one line looks like this: Duration, user, lat-start, long-start, lat-end, long-end 298, Casual,38.9101,-77.0444,38.91554,-77.03818 Each row in the CSV has two points and I ...
4
votes
1answer
422 views

How to repair and clean contours from high data resolution (lidar)?

I'm unsuccessfully trying to make a bathymetric map with contours extracted from Lidar data at 1 m resolution. The extracted contours have a lot of artifacts like dangles and islands. First I used ...
4
votes
1answer
86 views

Calculating “travelled distance” of a GPS track without including “stops”

I have a set of GPS tracks from a cycling event and I want to correlate their distance along the route. Problem is: when a rider stops, generally by entering a covered place, GPS keeps logging (low ...
3
votes
3answers
595 views

Calculating X and Y of line start and line end using ArcPy?

I have a series of polyline shapefiles and I am trying to automate the process of calculating the X and Y coordinates of the line start and line end using Python. I have added the 4 fields (startx, ...
3
votes
3answers
3k views

Polyline length calculation in ArcGIS 10/VB script

I used to run this length calc on my data in ArcGIS 8 and 9, and now it don't work in ArcGIS10. Can you tell me what I have done wrong? Dim dbllength as double Dim pcurve as icurve Set Pcurve = ...
3
votes
4answers
447 views

ArcObjects C#: select intersecting polylines

My questions seems trivial but it is a real blocker for me. So please help!!! How can I, using ArcObjects with C#, select only those polylines in one layer that intersect with each other? It sounds ...
3
votes
2answers
384 views

Extract Raster from Raster using Polygon shapefile in R

I am new to R and using the raster package. I have a problem extracting polygons from an existing raster file. If I use extract(raster, poly_shape) function on the raster it always creates a list ...
3
votes
2answers
332 views

How to add point to a polyline?

I have a polyline, and i want to add point (vertex) on a specific distance, like two meters for example. How can i do that?
3
votes
2answers
180 views

Line start and end nodes: determining what is a junction

I have a layer of points and polylines and want to determine which points are road junctions. I currently have all start and end nodes within 3m of my road network as a layer. However I cannot ...
3
votes
1answer
295 views

How to join 2D polylines and DEM into 3D polylines?

I got a simple question but could not find a satisfactory answer yet: I have a road network in 2D/PostGIS and a DEM. I want to turn the road network into 3D by retrieving the Z-value from the DEM. ...
3
votes
1answer
294 views

How do I find the intersection of two polylines in PostGIS?

I have a set of road conditions reported for small segments of road, and I am hoping to determine the specific subset of each segment which intersect with a route along the road so that I can draw the ...
3
votes
1answer
461 views

Pivot a polyline at vertex or distance using ArcObjects C#

I hope you can help me with that one. I'm using ArcObjects with C# trying to rotate only one part of a polyline at a vertex or distance along the polyline. The polyline is zAware and has values at ...
3
votes
3answers
108 views

Automated way to join

I have river networks (polyline) of several adjacent countries as shapefiles that almost match up at the borders, but not quite. Is there any way to automatically connect them to a consecutive river ...
3
votes
2answers
457 views

Calculating the distance between points and multiple lines

I have a point shapefile of about 100 points and a polyline shapefile of about 200 lines and I am interested in finding the distance between every point and each individual polyline. My polyline ...
3
votes
2answers
152 views

Polyline in shapefile

I'm still pretty new to arcpy and am still learning. I'm working on a script that has a polyline as its input. I'm able to traverse the polyline and get points at certain intervals. These intervals ...
3
votes
1answer
46 views

Add Z and M values to stream network produced from DEM

I created a stream network from an existing DEM. My ultimate project goal is to be able to select a river from my stream network and use the 3D analyst to generate stream profile (Elevation by ...
3
votes
1answer
169 views

How to check if geometry is M aware?

I am trying to determine whether my shape file that I pass is in M-aware (has M value). I keep getting an error Attribute Error: 'Polyline' object has no attribute 'hasM' Not sure what I am doing ...
3
votes
2answers
15 views

QGIS Line End Caps

When styling a road network where all sections of the network between junctions are separate paths, I style the ends of the lines to rounded to remove any gaps that might appear where the joins are at ...
3
votes
0answers
138 views

How to determine longest length of segmented polylines representing rivers? [duplicate]

I have a series of shapefiles using polylines to represent the hydro network of a region. As you can see in the picture, these polylines go into great detail. These polylines are very segmented even ...
3
votes
0answers
68 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 ...
3
votes
0answers
108 views

Shapefile and DEM: check rivers behaviour

I'm working with shapefiles representing rivers (rivers.shp), and DEM for the terrain elevation (terrain.tif). Basically, I want to check that my rivers (stored as polylines in my shapefile) behave ...
2
votes
4answers
315 views

How to turn all lines into one direction?

How can I turn all features of my polyline (postgis and/or shapefile) into one direction - it doesn't matter what direction. I know how to switch the direction of lines but I have no idea how to ...
2
votes
1answer
356 views

How to cut a line feature in QGIS 2.0?

I want to shorten a feature (a polyline representing a road) in QGIS 2.0. I tried the 'cut features'-tool that look like a pair of scissors. First I chose the right layer, and then clicked 'Toggle'. ...
2
votes
1answer
92 views

How to get the First and Last Point coordinates of a Polyline with Field Calculator in ArcGIS10

I'm trying to get the First Point coordinates (x,y) and Final Point coordinates (x2,y2) from a polyline in ArcGIS 10 with the Field calculator. I've added 4 (double) fields like StartX,StartY,EndX ...
2
votes
2answers
295 views

How to edit (particularly flip direction of) polyline obtained through UpdateCursor?

I want to flip the direction of a polyline feature obtained as a result of an Update query; e.g. lines= arcpy.UpdateCursor(myFeatureClass,myQuery) dsc= arcpy.Describe(myFeatureClass) try: for ln ...
2
votes
1answer
55 views

Using Python to create new point location based on various azimuth and distances

I have a feature class with thousands of points. In the same table with these point locations, I have two additional fields. One for azimuth, and one for a length (or distance) to move along that ...
2
votes
3answers
63 views

Create voronoi diagram from line segments

I'm looking for a way to create a voronoi diagram based on line segments instead of points. See the example below (taken from this presentation). Ideally I'd like something I can script from Python, ...
2
votes
3answers
112 views

R - color SpatialLines by attribute

I have a SpatialLinesDataFrame dataset of rivers in R. The dataset consists of lines (river segments) with a "Turbidity" attribute. I want to create a map and legend, where: Turbidity between 0 and ...
2
votes
3answers
68 views

Determining gaps in polylines and identifying continuing sections?

Is there a relatively quick way to identify where gaps < a certain size are present between polyline? E.g. would there be an easy way to join line likes the ones in the below image if the gap was ...
2
votes
2answers
919 views

Get all polylines from a shape file (containing polylines)

I have a *.shp file which contains only polyline features. How can I iterate over all the point features. Given ESRI Polyline example only uses already defined points to make polylines. But I want to ...
2
votes
1answer
107 views

Measuring polyline lengths running through a raster - is this possible?

I have a reclassified raster layer with 4 values and a vector layer of polylines. I would like to discover the length of the lines running through each raster value, or the percentage of the lines ...
2
votes
1answer
120 views

How do I calculate the coordinates of the median point of a polyline?

I have a shapefile with some polylines. For each one of these polylines I'd like to calculate the median of the polyline (i.e. the point that's equidistant from each end) and then, calculate its ...
2
votes
3answers
158 views

How can I merge a LOT of polylines automatically?

I have lots of MultiPolylines, three-dimensional arrays where the bottom level is an array of lat/lngs, the second level is an array of those points (a single polyline), and the top level is the group ...
2
votes
1answer
752 views

ArcGis 10 interpolate Z between polyline's vertices (IZ.InterpolateZsBetween ?)

Here's what's happening: I want to create a 3D line using only the height of some GSP points. I need to be able to extrapolate the vertice's height between where it's known to the one where it's ...
2
votes
1answer
126 views

Easiest way to find spatial differences between Polyline shapefiles

I run into this problem a lot. I have two polyline's and I need to test for Spatial differences in them. Usually I use Erase and I have my answer, but on this PC I now only have access to ArcGIS Basic ...
2
votes
1answer
175 views

What's the unit of measurements produced by “sum line lengths”?

My goal is to find the total length of roads per county for a particular state. You would think there would be a simple government spreadsheet with this information in it.... I cannot figure out how ...