# Questions tagged [length]

The longest extent of anything as measured from end to end

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### Understanding terms in Length of Degree formula?

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 ...
8k views

### Finding line length while editing in QGIS?

I am using QGIS. 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 being created?
13k views

### Calculating line segment lengths within polygon using ArcGIS Desktop?

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 ...
3k 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 sum(ST_Length_Spheroid(the_geom,'...
2k 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 ...
14k views

### What is unit of 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 = '%...
4k 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 ...
3k 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 )'...
4k 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 ...
16k views

### Getting geometry length in meters?

In PostGIS, the ST_length() function returns the length of a linestring in some units, but not in meters. Is there a function like ST_Length() but in meters?
561 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 ...
1k 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 ...
201 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 ...
254 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 ...
123 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 = ...
104 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 ...