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Questions tagged [length]

The longest extent of anything as measured from end to end

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1answer
41 views

Which coordinate system/ projection would you use to measure lines globally distributed?

Which geographic coordinate system /projection would you recommend to measure the length of hundreds of lines which are globally distributed (southern and northern hemisphere)? The lines have a length ...
1
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2answers
34 views

Measuring width of polygons, which is wider than long

Within my project I am trying to quantify and compare different submarine landslides with ArcGIS. Therefore, I created a polygon shapefile and mapped the spatial extent of each landslide. Now I want ...
2
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0answers
32 views

Calculate length of selected features in PyQGIS

I create a selection with getFeatures(QgsFeatureRequest()) and I want to calculate the length of the result which is a QgsFeatureIterator : select = QgsExpression(" myexpression ") selectedfeats = ...
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0answers
15 views

QGis 3.4.4 xyz-dependend height length calculation

We use $length to display the length of our lines. The outputs are only xy calculated We need to calculate with the height reference system DHHN 92 to get the true xyz lengths. How do I set up the ...
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1answer
39 views

Determining percentage of overlapping lines using QGIS?

i have a lines layer that represents the bikeways of my city, and also have another overlapping layer that represents the bikeways that need repairs. How can i get an analysis of the percentage or ...
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0answers
26 views

QGIS KML lengths appear to be wrong? [duplicate]

Every time I import a KML into QGIS the line lengths are wrong. A line that was 191 ft on Google Earth is now 260 feet in QGIS. How can I solve this problem?
2
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1answer
87 views

Different results using $length (field calculator) in QGIS versions 2.18 and 3.0

I use the field calculator to measure the length of LineStrings in my shapefile layer, but i get different results when using QGIS 2.18 or QGIS 3.0. If I am using the local coordinate system the ...
1
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1answer
81 views

QGiS 3.0: Line length without overlapping parts

I have overlapping lines in my layer and want a total length of the visible line without the overlapping part. i.e. I have two lines First one goes A-B-C Second one is B-C-D How do I get the ...
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0answers
19 views

Calculating route length per grid cell using fishnet

I have a problem determining the length of the routes (boat) I've surveyed in order to calculate the survey effort. I added the GPS points of the boat and then used the points to line tool and added a ...
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0answers
47 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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0answers
136 views

Attributing polygons based on line attributes

I'm using QGIS 2.18. I have a grid that I need to calculate Azimuth and length for each side. Most have 4 sides but some ( see Gird C below) many more , up to 12. My process now convert Polygon to ...
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1answer
56 views

Maximum Length parallel line

I have a polygon and I want to make parallel lines inside of the polygon. I need to have the maximum length when I sum the length of all of them. Each line must be 15 m apart.
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0answers
59 views

QGIS - Parallel Lines - Count length of one

I have a large layer of lines (telecommunication duct) with in parts several parallel lines that are close to each other (cause they lay in the same trench). I would like to count the length of the ...
2
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1answer
72 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 ...
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0answers
15 views

Calculating length of line using British National Grid projection? [duplicate]

I need to calculate the length of a line in (KM) in QGIS using the British National Grid as the Projection. Can somebody explain to me how to do this?
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0answers
26 views

$length returns text value that cannot be used to sum line lengths within polygon using QGIS?

I am trying to calculate the total length of roads within polygons using QGIS 2.18.15 The roads had no length field so I added one, but it came back as either text or 64-bit. This means I can't use ...
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1answer
538 views

Calculating length of polygon in ArcGIS Desktop?

I am using ArcGIS 10.2.1 Desktop with an Advanced license. My company has electric lines that go through people's yards. The areas around these lines require trimming occasionally, which necessitates ...
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0answers
99 views

Changing Virtual field properties in QGis 3.0

I have some existing virtual field with set Length and Precision An example: The formula was first set to rounding it by 2 digits With the current settings it displays 10.00 instead of 10 because of ...
3
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4answers
248 views

Calculate length of huge vector lines dataset

I have a MultiLineString vector layer from which I would like to calculate the length. I have tried to calculate the length with the Field Calculator by putting in the expression $length. The ...
3
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0answers
195 views

Wrong length values on QGIS 3.0.3 and 3.2

While using QGIS 3.x today I noticed that length values were not calculated and measured correctly on EPSG:32611. Calculating and measuring the same data on QGIS 2.18 latest LTR and 2.2 on EPSG:32611 ...
1
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1answer
84 views

$Length-attribute output

I created a layer to visualize cable-laying and want to export the sum of the cable-lengths to an excel file when I'm done so i created an attribute for it. How do I link an attribute to the auto-...
2
votes
1answer
247 views

Longest flow path in QGIS from single feature vector

I have got a vector layer with one feature (MultiLineString) representing a river network (s. below) without bifurcations. In addition there is a point shapefile containing the outlets of different ...
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2answers
89 views

Calculate perimeter of a large polygon using geodesic calculations

How do I calculate perimeter of a large vector polygon (polygon set) which spans almost half the globe? I guess regular calculations do not produce accurate results in this case.
1
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1answer
53 views

ST_Intersection preserving overlapping edges

I have a linestring that represents a bus route, and includes some overlapping sections where the bus has traveled back on the same street. When I ST_UnaryUnion the line, or ST_Intersection it with ...
0
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1answer
109 views

Buffering multiple feature classes from dataset based on length using ArcPy?

I am a beginner at Python and for my current project I am expected to list all polyline feature classes within a dataset, find the length, and then perform a buffer analysis based on it's length. This ...
2
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2answers
115 views

Choosing CRS for metric distance calculations? [closed]

I have the following ArcPy script to calculate total length of Polylines in a Feature Class/Shapefile: arcpy.Project_management('lines.shp', 'lines_projected.shp', arcpy.SpatialReference(TODO EPSG ...
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1answer
183 views

Calculate river distance to headwater for every pixel?

I already posted a similar question a few weeks before. But since my dataset changed and I still havent solved it, I thought its good to post a new question instead of editing the old. Using ArcGIS ...
2
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1answer
52 views

Calculate common length of two lines using ArcGIS Desktop?

I have a shapefile that consists of around 800 different lines. Now i have another shapefile which also consists line data. Is there a method which can help me calculate the shared length in the ...
3
votes
1answer
115 views

Difference in lengh calculations for ESPG:32632 and ESPG:4326

I have a shapefile with CRS ESPG:32632 where are shown some power lines of a ​​northern Italy area. I need to calculate the length of the lines and add it, as a new field, in the attribute table. I ...
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0answers
147 views

r.flow in QGIS 2.16.1 generates wrong output

I try to run the r.flow module to get the flow path length of my layer out. The input Layer is a DEM with pixelsize 0.0083 and the selected CRS (EPSG:32646, WGS 84/ UTM zone 46). First of all I ...
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0answers
68 views

Discrepency in Polyline length measurement

I have a specific question but I think it comes from a general confusion about measuring the length of a polyline feature. I downloaded the polyline shapefile for the Bigfoot Trail (a long distance ...
0
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2answers
75 views

Tracing or snapping to polygon border for measure tool

I am trying to do a simple measure of the length of seperate sides of a polygon depending on which other polygons it borders (in the image: the dark blue borders of the green polygon to the white area ...
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0answers
66 views

Measuring true length of polyline over terrain in QGIS? [closed]

I use QGIS for a variety of mapping purposes and also for managing UAV/drone data. I need to calculate the true length of a mapped fence over varying terrain for which i have a detailed DEM. Is this ...
0
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1answer
57 views

How to split lines that are larger than 10km?

I have a shapefile of line segments representing global rivers. The segments are all different lengths. If a segment is longer than 10km, I would like to divide it in to multiple segments approx 10km ...
0
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1answer
919 views

Calculating length of polyline using ArcPy? [closed]

I have a polyline shapefile that has only one polyline. How do I calculate the length of that polyline using ArcPy?
0
votes
1answer
56 views

Using intersect/clip for polyline to polyline features resulting in Warning 000117 ArcMap? [duplicate]

I am trying to measure the length of a polyline from its origin to its intersection with another polyline. The application is to find out the distance from a meteorological station to the coastline. I ...
4
votes
1answer
65 views

Incorrect measurement of intersection between polygons

I have a map divided in parts using polygons, and I want to measure the length of the boundary between each pair. I am using this script from a tutorial to find the actual neighbors, and then measure ...
0
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1answer
485 views

Apply onEachFeature only on Points. Ignore LineStrings

I have a couple of GeoJSON files where each GeoJSON file contains a LineString and some Points (a LineString represents a hiking route and the points represent shelters). I would like to display the ...
1
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1answer
413 views

Calculate length of Multilinestrings/Linestrings/Polygons in geoJSON file

I have a couple of routes on my map where I would like to display the length of each route. I think I've found what I was looking for here: https://github.com/tyrasd/geojson-length, but I'm not sure ...
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0answers
110 views

Extending Polygon to Another Polygon with Automation? [closed]

I need to extend the polygons in blue to match the red polygons using automation, since there are thousands of these. It seems like a simple thing to do, but I have not found a suitable way to ...
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0answers
244 views

How to loop and calculate length of each segment on a line having 2 distinct layers of points and lines?

I have a layer of polyline and a layer of points. My objective is to calculate the length of each segment along my polyline. I tried a code but it returns the length between points that are not even ...
1
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1answer
90 views

Calculating length of Appalachian Trail

I'm new to GIS and wanted to start play around with some data about the appalachian trail (AT) and PostGIS. However I already failed at the first and most simple task to calculate the length of the ...
4
votes
2answers
266 views

How is the st_length function stored in an Oracle geodatabase?

How is the st_length function stored in an Oracle geodatabase? Is it in a: PL/SQL function Separate .dll library Somewhere else? I've noticed that the sde.st_length function works, even when the ...
4
votes
1answer
260 views

OGR2OGR how to update a new column by the length of polyline

Hi I can update new column with area of a polygon object, but don't know, how to update new column in polyline layer with length of polyline. This works very well for AREA: for %%f in (*.tab) do ( ...
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0answers
43 views

Seeking Brazil wide reference system to compute road length?

I've a Brazil road layer that include start km and end km for each road, some are empties. Have checked and some of the values are wrong so I'll calculate road length by myself. I use ArcGis, but can ...
1
vote
1answer
196 views

QGIS object selecting if any segment length is longer than [closed]

I have a polygon layer with generated triangles covering for example district or city area. I need to select all the triangles if any triangle (object) segment is longer than 100 meters. Picture: ...
3
votes
1answer
588 views

Measure length of each segment for a polygon in Postgis

I have a polygon table in PostGIS and need to calculate the length of each line segment. How can I achieve this? I have done it in QGIS but would prefer to do it in the database. I have found ...
1
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1answer
73 views

Calculating length of curved line derived from intersection between two polygons using ArcPy?

I'm trying to get the density of intersection points along their related ellipse. What I'm missing is the length of the arc of the ellipses comprised in between the yellow polygon (which is a ...
0
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0answers
72 views

Identify the length and orientation of the features in P2 relative to features in P2? (ArcGIS)

I try to measure the maximal length and orientation of features in one shapefile (S1) relative to polygons in another shapefile 2 (S2). My goal is to evaluate the spreading of patches of beetle-...
4
votes
1answer
244 views

QGIS: Displaying total length of lines in print composer legend

In the print composer (also in the layer selector) I can choose to automatically display the amount of objects in that category in square brackets. That is useful for point features/layers. But in the ...