Questions tagged [length]

The longest extent of anything as measured from end to end

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votes
1answer
143 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 ...
2
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2answers
132 views

Flow Mapper wrong line length calculation

I'm finding some trouble with the length calculation in the Flow Mapper plugin. As you can see in the picture below the length of the 2 lines C001-C021 = 4233.7986... C001-C009 = 6069.3053... is ...
2
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1answer
847 views

Distance Between Two Points vs Length of Linestring

So I have two points that I want to calculate the distance between. If I use: SELECT ST_Distance_Spheroid(point_a, point_b, 'SPHEROID["GRS 1980",6378137,298.257222101]') / 1000 FROM ( ...
2
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1answer
59 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 ...
2
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1answer
245 views

Changing parallel line length to split polygon in QGIS?

I have a polygon which I want to split with a selected line with a parallel line. I have made the parallel line but it's lenght is not enought to split the polygon. It necessary to be parallel with ...
2
votes
1answer
256 views

Tag for calculating way length in osm2pgsql?

There is a special tag 'way_area' in osm2pgsql creating a database column that stores the area of polygon features. So is there something like this for calculation of length of line objects?
2
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1answer
396 views

How to examine length of vector lines in qgis/grass?

I have vector layer of lines. How can I examine length of lines?
2
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2answers
166 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 ...
2
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1answer
160 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 ...
2
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3answers
2k views

How to determine the length of a KML line tracing

I have a KML file which contains a line feature representing the passage of an Optical Fiber connecting two cities. I can trace them nicely in QGIS and OpenStreetMap. I would just like to know how I ...
2
votes
1answer
40 views

Adding $length on the fly when adding line feature

is there a simple way (without writing script or python skills) to auto calculate and auto populate length attribute in QGIS? When I add a new line feature in my layer, I'd like the attribute length ...
2
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1answer
385 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 ...
2
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1answer
605 views

Can we take the length of a linestring by calculating ST_Distance from its ST_StartPoint and ST_EndPoint?

I took the values of my StartPoint and EndPoint by doing this procedure: a) SELECT COUNT( CASE WHEN ST_NumGeometries(geom) > 1 THEN 1 END ) AS multi, COUNT(geom) AS total FROM public.roads; ...
2
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1answer
249 views

Postgis different result using st_length and st_intersection

I'm trying a simple intersection between line and polygon SELECT p.id, st_length(st_intersection (l.geometry,p.geometry)) as partial_length, st_length(l.geometry) as line_length FROM line l , ...
2
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1answer
487 views

QGIS polyline length calculation [closed]

I meet a problem while I try to calculate the length of a polyline in QGIS in the attribute table. I created a new column with the function "$length" inside (type: real, 10 digits and 3 digits of ...
2
votes
1answer
542 views

Line calculation from KML file

I am a beginner in QGIS 2 and Mac OSx Mountain Lion I need to get line length in meters for different gps waypoints. 1 I import kml file to create a new vector shape (this works fine). The projection ...
2
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0answers
111 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 = ...
2
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1answer
754 views

Splitting polygon features at specific widths using ArcGIS for Desktop?

I have a group of islands and I need to divide them into different segments based on feature width at several locations. There are four values for width (50m, 100m, 200m, and 300m) which I need to ...
2
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0answers
436 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
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0answers
195 views

How to add column to attribute table using field calculator with $length function?

I used the following code to add a separate column to the attribute table with the length of features. from PyQt4.QtCore import QVariant from qgis.core import QgsField, QgsExpression, QgsFeature vl....
1
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1answer
186 views

Length of reversed geometry in meters

I know that a similar question has been asked multiple times here (a great answer can be found here: How can I get the geometry length in meters?), but in contrast I want to get the length of the ...
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1answer
513 views

Using ArcPy to get length of Polyline created?

I am trying to get the length of Polylines I am creating immediately after I create them. The code I am using: arcpy.Polyline(arcpy.Array([arcpy.Point(firstx, firsty), arcpy.Point(secondx, secondy)])...
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1answer
107 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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1answer
63 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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2answers
153 views

Incorrect length from Flow Length tool

Why is my flow length tool giving value less than one? Isn't a flow length tool supposed to give the maximum length of upstream flow to the cell? Then, how come? I am using coordinate system of GCS ...
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2answers
3k views

Qgis - need to draw exact lines (mtrs) with fixed angle

I use GIS 1.8. I have the need to be able to draw exact lines and shapes on a bing map. (This is to project a yet to be build greenhous project on a map to show what i would look like). I have ...
1
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1answer
226 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: ...
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2answers
437 views

Separating polygons within layer and measure line through each polygon using ArcGIS Desktop?

I have 3 layers of polygons, each layer with multiple polygons spatially separated, although the layer only counts it as 1 polygon. I have a layer with a line going through these polygons. What is ...
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1answer
63 views

Getting bike lane length with QGIS?

I am trying to get bike lane lengths from the following data set. To do so I have tried using the add geometry attribute from the processing toolbox. I have tried both calculate using Layer CRS and ...
1
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1answer
50 views

Calculating the length of a single edge in QGIS

I need the correct length of a edge between to points(yellow line in the picture below) in the unit [m] for validation of an equation. I just found the possbility to add geometry (length) to the ...
1
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1answer
49 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 ...
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2answers
73 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 ...
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2answers
96 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
97 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 ...
1
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1answer
337 views

How to depict line symbols with length from attribute

I want to depict angled drill holes as a horizontal traces (plan view). I have a CSV file with X,Y,Azimuth and Horizontal length. Using the simple marker I can get a line pointing in the right ...
1
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1answer
102 views

How to divide and split an arc into specific lengths?

I have an arc shapefile for a city which represents the rail road route. It is a single attribute arc that I would like to separate into segments of 90 ft. For example, if the standard track length ...
1
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1answer
222 views

FME Segment Line with To/From Distance Values from Excel?

I have a large road network with some basic attributes like ROAD NAME, ROAD TYPE, LENGTH. Each road has been segmented but these segments are wrong for the new schema. I have successfully (mostly!) ...
1
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1answer
576 views

Create a line from an array and measure its length with PostGIS (ST_MakeLine, ST_Length)

do I understand it correctly that it is possible to create a line out of an array with the function ST_MakeLine()? I would like to create a line from several points (more than two) and then calculate ...
1
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1answer
554 views

Calculating field length in certain directions (raster)?

Currently I'm working on winderosion. For my purpose I like to calculate the length of agricultural fields in certain wind direction. I would like to do it for raster. To be more precise, I have ...
1
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1answer
737 views

Problem of linear records with zero shape length and no geometry in attribute table

I am working with a bicycle and pedestrian facility file geodatabase in ArcMap. I noticed a some of the records in the shapefiles/feature classes have a shape length of zero in the shape length ...
1
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1answer
249 views

Line feature, Merge and Dissolve

I have a layer with several polygons and a layer with line above these polygons. Its like a map and a road network on it. I have to find out the length of line in each polygon. I used the intersect ...
1
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1answer
659 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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1answer
65 views

Are degree based length/area measures comparable across regions?

I have global shp files of basins (polygons) and rivers (lines). I wish to calculate a measure of stream length per basin area. It should be comparable across world regions, e.g. I wish to compare ...
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1answer
1k views

Store into a list multiple lists

I have list of 50 lists of pairs of SpatialLinesDataFrames. That means I have something like: [[1]] [,1] [,2] [,3] [1,] spldf1 spldf3 spldf5 [2,] spldf2 spldf4 spldf6 [[2]...
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1answer
486 views

How to get correct lengths when switching from GCS to PCS?

I'm working on ArcMap 10 and need to get the lenghts (in meters) of the segments composing my line feature class. GCS of the line is WGS_1984. Extent of this data should be: Left 11.236520 dd, Right ...
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1answer
598 views

How to split/divide linestrings of larger lengths in postgis

I want to split/divide linestrings in my data. I have roads data and I want to have every road segment having length not more than 250 meter. Check the shape length of this particular line feature. I ...
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1answer
1k views

3D and 2D lengths of lines in ArcGIS

I have a 2D road segment and convert it into 3D using a raster in ARCGIS 9.3. So, what i see is that the length of 3D road segment is still the same as the 2D road. How can this be? As due to ...
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0answers
33 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
63 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
141 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 ...