The longest extent of anything as measured from end to end

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1answer
45 views

Calculate Cumulative Distance (incorporating slope) of a Line Feature Using ArcGIS

In ArcMap, when creating a line feature class within a geodatabase, the length of each record is automatically derived upon creation. This length is based on a distance measurement for a planar ...
1
vote
1answer
26 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 ...
2
votes
1answer
68 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 ...
0
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0answers
37 views

In which units is the result of the flow length tool displayed?

I want to use the flow length tool in ArcMap 10.2.1. to calculate the downslope distance along the flow path of a DEM with a cell size of 5m. The explanation of the the flow length tool says that the ...
1
vote
1answer
40 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
votes
2answers
34 views

Wrong length of edges

I want to make a network analysis with ArcGIS. I am using openstreetmap-data from the Geofabrik but I have big problem: The length of my edges are not the right one. The length of the edge is for ...
3
votes
0answers
30 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 ...
1
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0answers
36 views

$length calculation anomaly

A polyline layer's (green) length is being calculated via $length. Result: ~100 meters (EPSG 31466). A buffer of 5meters is created and via Voronoi Polygons (and several other steps) a centerline is ...
2
votes
2answers
50 views

QGIS - 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 ...
0
votes
1answer
34 views

Arcpy - LayerList - Count/Length [closed]

I use arcpy to load all layers in the current map document, and I need all layers but not the last one (this is my layer for the symbology template). How can I access the length or count of the ...
2
votes
1answer
133 views

Get LineString length in meters (Python, GEODjango)

In a Django model, I have a LineString field which holds GPS coordinates of a street route. I know that I the .length holds the length of the LineString, but I don't know what unit the returned value ...
0
votes
1answer
133 views

PostGIS Get the POINT that is x meters away from a fixed point on the route (LINESTRING)

We have a route network stored in the routes table (LINESTRINGs). Basically every sedment (between two vertexes) is inserted as a separate row in this table. Among that we have a locations table (...
0
votes
1answer
176 views

Calculating slope length using LS-tool

Does anyone know how to get LS-tool mentioned in Zhang et al 2013. https://www.researchgate.net/publication/256938578_Extension_of_a_GIS_procedure_for_calculating_the_RUSLE_equation_LS_factor I tried ...
1
vote
1answer
74 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
vote
1answer
96 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]...
2
votes
1answer
57 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
304 views

Calculating the length of the network lines inside polygon in QGIS 2.10.1

I am working with 2 datasets: delineations of the neighbourhoods traffic network. This is how they look: I would like to calculate the length of the roads per neighbourhood (polygon). As you ...
8
votes
1answer
423 views

Is there a best practice for the length of fields?

At my work have inherited several shapefiles that originate from MapInfo that I am bringing into a new project in QGIS. I have the opportunity to change the column names, add and subtract columns and ...
1
vote
0answers
38 views

Calculation of length in QGIS [duplicate]

I am trying to calculate the length of lines, which were convatede before from gps to Shapefile (vector layer). I tried it with "feldrechner" (matrix calculator?) and the most time I got 0, or in the ...
1
vote
1answer
76 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 ...
1
vote
0answers
239 views

Drawing features with specific dimensions in ArcGIS [closed]

I am having some issues drawing transect lines in ArcGIS. I need to create some lines that have specific lengths (20m and 30m). My Map units are set to 'meters' and coordinate system is NAD UTM 10. ...
0
votes
1answer
35 views

Clipping line feature to MANY polygons for measurements [closed]

I am looking to measure the length of stream segments(line) on numerous tax lot properties (Polygon). Is there a tool that will allow me to "Cut" or "Clip" streams to tax lots to estimate not only ...
3
votes
3answers
310 views

How to calculate path length of each point from the start using arcpy?

As shown in the picture below I would like to calculate the path length of each point from the start. Can anyone give me some help in writing this in python for ArcGIS?
1
vote
2answers
179 views

Check shape orientation

I have a shapefile with many minimum bounding box (envelope) polygons and I need to find out, if the boxes are rather landscape or portrait format. (See pic below, one of the selected boxes should be ...
1
vote
0answers
141 views

Deriving length values from GPX files in QGIS

I’m missing something real obvious and I apologize for revisiting a topic addressed in several Q&A’s here. I’m an experienced GIS user (not programmer) who’s new to QGIS (can’t afford Arc in ...
1
vote
1answer
399 views

How to change the attribute length of an existing field afterwards

I already have about 100 values in a field in QGIS. I set it to 50 characters because I was thinking that would be enough. But that was wrong. I need more space in the column. But there is no way to ...
1
vote
0answers
306 views

Flow length analysis only shows pixel value, how to get length?

When I create a flow length analysis, and use identify tool on a cell in the layer, it just shows "stretched value" and "pixel value" I don't understand how it's supposed to show length. I'm using ...
1
vote
0answers
382 views

Length difference between Google Earth and ArcGIS for Desktop?

I have drawn a complex path with multiple vertices in Google Earth (GE) Pro and its measurement property is shown as being 2,460 nm. It is located East of Australia. If i import this KML into ArcGIS ...
1
vote
2answers
241 views

How to separate polygons within layer and measure line through each polygon?

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 ...
9
votes
2answers
642 views

POSTGIS get the max length of the polygon and the average width

I have in postgis a polygon type table. I need to calculate automatically the maximum length of the polygon: And the second one is the average width: I am doubting rigth now if this is possible ...
1
vote
0answers
56 views

QGIS (2.0.1): Field calculator for length not working - values way too high

Same problem as another thread: Field Calculator returning incorrect length and area values Trying to calculate length of a line shapefile, and field calculator is returning values that are way too ...
2
votes
0answers
144 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
128 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....
2
votes
2answers
99 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 ...
3
votes
0answers
562 views

How to convert length in Decimal degrees to meters programmatically?

I'm new to qgis and I want to find the length of some roads in a map. So I used the following code, from shapely.wkb import loads def getLength(): layer = qgis.utils.iface.mapCanvas().currentLayer()...
5
votes
1answer
4k views

What units are shape_length in?

When generating polylines from a series of points, I used "Points to Line" tool. From this, Arc generates a polyline feature class, which includes the attribute shape_length. What units are these ...
1
vote
1answer
428 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
votes
0answers
520 views

FME - calculating distance to points along a line

I am new to FME, and trying to get my head around what should be pretty straightforward issues, but I find myself going around in circles Basically I want to determine the distance (chainage) to a ...
2
votes
1answer
137 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?
1
vote
1answer
314 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
vote
1answer
369 views

How to calculate highway lengths using QGIS? [closed]

I need to create a network of highways in 8 states of the USA. Eventually, I need their length, the speed and if possible average daily traffic volume, I don't know how to extract this information. ...
1
vote
1answer
211 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. ...
0
votes
1answer
43 views

Postgis add Geography to function()?

i was wondering im getting different results when using geography() on different positions within a query. So, whats the most accurate way of forcing geography() over a functions with geometry ...
0
votes
1answer
424 views

Field Calculator returning incorrect length and area values when QGIS project is reopened

Similar to Field Calculator returning incorrect length and area values, but as always slightly different. I have QGIS 2.0 and when I create a polyline shapefile, the field calculator returns the ...
2
votes
1answer
120 views

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

I have vector layer of lines. How can I examine length of lines?
4
votes
2answers
2k views

What is the unit the shapely length attribute?

I'm doing a very simple calculation of the length of a polyline using shapely: from shapely.geometry import LineString ... xy_list = [map(float,e) for e in xy_intm] line = LineString(xy_list) s = '%...
4
votes
2answers
1k views

Using Calculate Field (Data Management) tool to calculate 3D Length in ArcGIS 10.1

I'm relatively new to the world of model builder and scripting, so it's likely there is a very simple solution to the question I've been trying to figure out. I'm trying to create a tool that takes ...
3
votes
1answer
415 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 ...
5
votes
2answers
5k views

Length of a degree: where do the terms in this formula come from?

Online calculators such as http://www.csgnetwork.com/degreelenllavcalc.html (view page source) use the below formulas to get meters per degree. I understand in general how distance per degree varies ...
1
vote
1answer
322 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 ...