The longest extent of anything as measured from end to end

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1answer
22 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. ...
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1answer
27 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 ...
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1answer
58 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 ...
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1answer
29 views

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

I have vector layer of lines. How can I examine length of lines?
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2answers
188 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 = ...
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1answer
311 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 ...
2
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1answer
80 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 ...
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2answers
205 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 ...
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1answer
60 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 ...
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77 views

Identify segments that share a last vertex with the first vertex of selected segment

This has been marked as a duplicate to Connecting line features and determining the length of the longest line but I believe there are some subtle differences. And to be honest I'm not an advanced ...
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1answer
88 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 ...
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0answers
47 views

Network Analyst: How to sum cost attributes without length with closest facility tool

I am working on Safe Routes to School, and have created a network dataset. Each segment of the newtork has a 'walk_score' assinged (0,1,3,5,10), based upon street classification and sidwalk ...
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1answer
144 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 ...
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1answer
212 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 ...
3
votes
3answers
225 views

Why is sum of st_length() of segments 20% too big?

I'm running a query to return the total length of some bike paths, from OpenStreetMap. Compared to the known actual length of these paths, they're all a bit too big - something like 10-30%. I know it ...
2
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1answer
267 views

Problem about converting raster to polyline and calculating total length

I have raster file of line segment. I need to convert it to line and get the distance of that line. How can i do using Python and ArcGIS 10? I have tried with GIS tools Convert Raster to Polyline but ...
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1answer
122 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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2answers
160 views

How to create a new column to store the length of a linestring in postgis?

I am working with pgRouting, following this nice guide:A Beginner’s Guide to pgRouting I am now in this step:Calculating shortest routes, with these codes below SELECT * FROM shortest_path(' SELECT ...
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1answer
236 views

ArcObjects Java Calculate Line Length

I'm relatively new to programming and ArcObjects. I'm trying to simply calculate the length of a line (test.shp) using ArcObjects and Java. I've tried the code below with no luck. This is simple in ...
2
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1answer
176 views

Sum line length with clip intersect? [closed]

SELECT sum(st_length(st_intersection(POLY.geom, LINE.geom))) AS sum_line_length... Is this function OK to calculate the sum of lines length? Wonder if it do the clip line where one line go from one ...
2
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1answer
2k views

How do i calculate line segment lengths within a polygon?

I have a layer with line segments and a layer of polygons (in this case, buffers around points). I need to create a new field for each polygon that contains the total length of all line segments ...
6
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2answers
461 views

How to create line with exact same length over and over again?

I need to draw 30 meter lines in specific places. Ctrl+l is too annoying to do everytime. Is there a easy way to define specific same length for a line that I need to draw many times?
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1answer
494 views

How to emulate a specific vector grid in QGIS?

I would like to analyze data included in a pdf file. The file contains information on characteristics of 16km grid cells for a specific study area. The file also includes a map displaying the grid. I ...
4
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1answer
125 views

Measurement not correct in QGIS 1.8

I have a SHP file of sub-areas of U.S. counties (roughly about the size of a Census tract) that I've reprojected into a 'true distance' projection (World Equidistant Cylindrical) in QGIS 1.8. However, ...
2
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1answer
103 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 ...
3
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3answers
679 views

How to Calculate length of polyline geometry for several tables in PostGIS?

PostGIS database contains several geometry (polyline) tables (with names "D1_r", "D2_r", "D3_r"). I calculate length for one "postgis layer" use request: SELECT ...
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3answers
2k views

How to create a rectangle polygon with set lengths in QGIS?

I have a search area i want to outline. and i need it to be 1km by 2km. is it possible to achieve this in QGIS. I can create a rectangle polygon but only guess the lengths.
6
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1answer
260 views

Can you permanently set the polygon/polyline segment length?

I'm trying to create a several hundred polygons in ArcGIS 10, each of which may have up to several hundred vertices. For consistency sake I would like each line segment in these polygons to be of a ...
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0answers
329 views

Length in meters arcobjects [duplicate]

i have a an array of polylines in epsg:3857 projection, and i want to calculate length of each polyline. i am new to arcgis and arcobjects, i couldn't find the functions that i need. Should i use ...
3
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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 = ...
5
votes
3answers
735 views

How to find line length in QGIS while editing?

I am using QGIS (before, I used ArcView). I would like to know if there is any way during the editing phase of a vector (line or polygon) to know the length of the line (total and partial) that is ...
6
votes
1answer
2k views

How to measure length of line accurately?

In postgis 1.5 for the below given query the answer is 1540651.62674101 meters , SELECT ST_Length(ST_GeomFromText('LINESTRING(77.83042478941326 9.98463896136159,78.03469506809812 23.90398909552571 ...
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3answers
640 views

ArcGIS Surface Length Tool equivalent in FME

I am trying to calculate the 3D length of a line. I currently have a rather complex and cumbersome model built in ArcGIS Model Builder that uses a tool called "Surface Length". I was wondering if ...
3
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0answers
891 views

How to get turn angle, line orientation and line length in ArcMap 9.3.1?

I am mapping and analysing animal movements using arcgis 9.3.1 along with Hawthorne Beyer's GME, and am trying to utilise the correlated random walk commands, but in order to do this I need to find ...
10
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3answers
1k views

Looking for a pythonic way to calculate the length of a WKT linestring

I was quite unsatisfied with Calculating Length of Linestrings in WGS84 in Miles. It kept me wondering if there is a more convenient, Pythonic way to calculate the length of a WKT linestring according ...