Questions tagged [length]
The longest extent of anything as measured from end to end
215
questions
3
votes
1
answer
54
views
Adding length constraints to line features in QGIS
I want to add length constraints to my line feature column 'type' depending on the field value, to make it impossible to create a new line longer than x m.
Below is a screenshot of the categorised '...
- 87
5
votes
1
answer
72
views
Selecting top two features with longest length in the line vector file in QGIS
I have a line vector file and I need to select two lines with the longest length using expression. I am familiar with selecting the line with the longest length:
length($geometry) = maximum(length($...
- 305
0
votes
0
answers
23
views
In QGIS, how can 'Points along Geometry' give a significantly greater length than $length of a line?
If I use either QChainage or 'Points along Geometry' to put length markers along a route, I get a different (longer) total than if I calculate the whole line length with $length.
It's not trivial, ...
0
votes
0
answers
5
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Can't aggregate data by date to calculate point path length
I have a table with the coordinates of the movement of the car, its id and the time the coordinate point was received. When I try to calculate the mileage of a car by grouping points by day, an error ...
3
votes
2
answers
100
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Show length of selection
Today I was calculating length of features to know how long a certain route will be.
I was wondering if there is a quicker way to find out the length of a selection of features?
I am looking for a ...
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1
vote
1
answer
39
views
Compute length of geometry column after reprojecting using to_crs()
I have a GeoDataFrame created from a shapefile having CRS EPSG:4326.
Even though the GeoDataFrame has no src assigned the coordinates are correctly expressed in this CRS.
I want to calculate the ...
- 141
1
vote
0
answers
43
views
Calculating the length of lines using PyQGIS
I have a polygon layer ('anlage') and a line layer ('Linie'). I intersected these two shapefiles and created a new shapefile and a new field to calculate the length of intersected lines. But the ...
- 75
1
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0
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41
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Line lengths differ depending on method used QGIS3
I have a layer containing multiple non-overlapping lines (MultiLineString). I want to calculate the length of each line. However, I get three different answers depending on the method used to ...
- 59
0
votes
2
answers
78
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Adding new fields with conditions and calculating the sum of lengths and numbers using PyQGIS
I am developing a new plugin using Python in QGIS. I want to get an output with the result of a specific attribute table from another layer already existing in my project => layer "SUPPORT&...
2
votes
0
answers
44
views
Calculating length of common boundary with virtual layer in QGIS problem with output
I'm calculating the length of common borders of 10 sets of polygons with the solution posted in this question: https://gis.stackexchange.com/a/360776
In 8 of the 10 datasets everything works fine, but ...
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4
votes
1
answer
119
views
Setting symbol rendering based on feature visible length in QGIS
I am displaying symbols at the middle of lines and I would like them to be visible only when the length of the feature displayed on my screen is long enough (which I call "visible length" in ...
- 469
1
vote
1
answer
44
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How to dissolve touching polylines [closed]
I want to dissolve some polylines clipped in a series of polygons, but since there are different polylines in the polygons, I cannot dissolve those with the attributes of polygons. For example in the ...
- 11
0
votes
0
answers
28
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Null cells - length calculator
I have zero cells when entering the code. No errors in the console. Why?
QGIS 3.16
fn = 'H:/roadst.shp'
layer= QgsVectorLayer(fn, '', 'ogr')
pv = layer.dataProvider()
pv.addAttributes([QgsField('...
0
votes
0
answers
58
views
Inconsistent Line lengths and distance measurements
I've imported OSM data, including specifically LineString railroad tracks for different subdivisions.
I want to distribute mile markers at fixed intervals, but am getting very different distance ...
- 1
6
votes
2
answers
326
views
Splitting lines by multiple polygons, taking length of particular segment, using PostGIS
I have a table of 100k+ non-overlapping POLYGON features, and a table of 50k+ simple LINESTRING features (each line has only 2 vertices). The below is a common arrangement of these features on a map, ...
- 1,687
0
votes
1
answer
349
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Calculate length using GeoPandas
I have a shape file "Line1.shp". It has only one feature. When I calculate the length in ArcGIS Pro using "Calculate Geometry" and selecting units as "Meters" and ...
3
votes
1
answer
81
views
Getting line length of geometry of parent feature as default value in child feature in QGIS
I have:
a parent line-layer 'MyParentLineLayer' (referenced layer) with a field "parent_uuid" (referenced field).
a child geometryless-layer 'MyChildLayer' (referencing layer) with a field &...
- 541
1
vote
1
answer
92
views
Making lines from points and classifying them by length in QGIS
I have a QGIS point layer with several points with no attributes except the Id field. I want to make a line from each point to the rest of the points. In addition, I would like to get two new fields, ...
- 103
6
votes
1
answer
521
views
AssertionError when applying expression to field value with PyQGIS
I am trying create new columns in an attribute table and fill them with values with expressions using Python Console in QGIS.
I successfully create the new columns but when I try to fill them, I get ...
- 133
2
votes
1
answer
296
views
Converting array to polyline using Arcade with ArcGIS Pro
Arcade/ArcGIS Pro 2.9:
I have an array of polyline vertices:
[[[670634.3148,4862051.3579,null],[670719.3321,4862051.0072,null],[670721.44381227,4862055.2956567,null],
[670724.26721751,4862059.1529319,...
- 1,054
0
votes
1
answer
180
views
How does SDE.ST_LENGTH() get calculated?
I have an Oracle 18c SDE.ST_GEOMETRY polyline FC. The lines in the FC have true curves.
If I query for the length of the lines in SQL using SDE.ST_LENGTH(SHAPE), how does the length get calculated?
...
- 1,054
4
votes
2
answers
302
views
Grouping and measuring total length of road based on specific attribute in QGIS
I have this dataset that describes the cycleways of a city.
I want to measure the km of cycleway for each type of highway (residential, track, unclassified, ecc) and then calculate the percentage of ...
- 161
1
vote
1
answer
2k
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Getting total length of polyline from Leaflet draw?
I'm quite new when it comes to Leaflet and this is my very first question asked here so I'm not experienced. While I was drawing polyline I noticed that you can get current distance while drawing it:
...
- 13
10
votes
1
answer
442
views
Calculating length of each polygon side in PostGIS
In PostGIS, I want to calculate the length of different sides of a polygon. I know how to calculate a perimeter but how to calculate length side by side?
Perimeter is as a sum of side's length so I ...
- 1,454
4
votes
1
answer
290
views
Merging line segments using length rules in QGIS 3
In QGIS 3 I have split a line dataset (road dataset where each road is an individual segment i.e. split at intersections) into segments using the "Split lines by maximum length" tool with ...
- 101
6
votes
1
answer
207
views
Calculating line lengths of road network in PyQGIS
I have a road network 'TR_ROAD' with EPSG:4283 crs and 1200 features. I am trying to calculate length of each line segment in road by using "length" geometry in PyQGIS.
When I tried below ...
- 835
4
votes
1
answer
175
views
Calculating cumulative line length on large dataset
I have a line split into segments that I want to calculate the accumulative length for, like this:
I can achieve this easily on a smaller dataset with this inbuilt function in the field calculator in ...
- 470
0
votes
1
answer
233
views
Calculate length and width of polygons using Arcade in Expression Builder in the attribute table in ArcGIS Pro [closed]
I am using attribute rules to automatically update cells in an attribute table. I need to auto-calculate the length and width of polygons as the user creates them.
Is there a way to do this using math/...
- 1
1
vote
2
answers
276
views
Drawing circle of a fixed radius in meter, rounding error?
I would like to provide an option to draw a circle of a fixed radius in meters.
My problem is that if I enter 5 meters, I'm getting 4.99 meters if pass the LineString to sphere.getLength.
My code so ...
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6
votes
3
answers
490
views
Calculating sum of line length for hundred vector layers
I usually calculate total line length by adding a $length field and going to summary statistics. How would I do this if I have many layers? Is there a faster way? I batch added the $length to all of ...
- 449
6
votes
2
answers
490
views
Finding the longest horizontal line inside polygon in QGIS
I have a state polygon like the pic shown below, is there a way to find the line which is the maximum horizontal line?
Like this, but I want the maximum distance line.
- 79
0
votes
0
answers
21
views
Converting Lat Lon points to line, then calculating distance travelled in QGIS
I understand this question, or variations thereof, gets asked regularly but no matter what I try I can't seem to convert points from GPS tracks to lines, then calculate the distances travelled. This ...
- 1
3
votes
1
answer
86
views
Length of shared borders between polygons using Virtual Layers
I have a map with many counties, and I estimated the length of the common borders using one of the answers from this question posted a year ago.
The properties of my layer look like this:
I did the ...
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2
votes
1
answer
95
views
Query for calculating length of lines inside polygon gives empty output [closed]
I am writing an SQL query to calculate the length of lines inside a polygon.
SELECT r.*, st_length(st_intersection(r.geometry,b.geometry)) AS Length_Inside
FROM Gen_Line as r, Buffered as b
WHERE ...
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4
votes
1
answer
95
views
How to count the number of 100m length chunks in a table with line geometry?
And by chunks I do not mean segments so I can't use st_segmentize for this
In other words I have a linetable which has many lines of varying length. Example:
id | st_length(geom) | intended count for ...
- 2,258
4
votes
1
answer
116
views
Autochange length of line not working in QGIS 3
I have the line with calculated length both in meters and in feet.
The problem is, that when I delete some unnecessary nodes it doesn't change at all.
I tried to find some hint here:
Finding line ...
- 3,759
2
votes
2
answers
207
views
Calculating the length of two shapefiles in QGIS
I created the yellow area as a shapefile by hand. Then I calculated the perimeter. I also created another shapefile (blue) manually and calculated the length, see image 1.
The next step was to ...
- 55
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votes
0
answers
55
views
Calculating the greatest length of a polygon using QGIS [duplicate]
I'm new to QGIS and I need to know the easiest way to calculate the greatest length of a polygon. I already know the "rule" tool but I want to do it automatically because I have a huge ...
- 1
11
votes
3
answers
3k
views
Calculating semi-major and semi-minor axis length of an ellipse in QGIS
I have a layer that contains ellipse-shaped geometries. The layer has projected CRS and there are also rotated ellipses in the layer. I couldn't find a tool or plugin related to semi-major and semi-...
- 72.4k
0
votes
0
answers
247
views
Calculating the longest path length in drainage network using Python
I have a drainage network and I want to obtain the longest path length between two coordinates of the shapefile; is there is a way to automate this process in Python?
For example, in the image, I want ...
- 17
2
votes
0
answers
82
views
Selecting, sorting, and grouping spatial data (lines) by length and proximity
I'm working on a project where I have a bunch of lines inside of polygonal land parcels. Here's a rough sketch of what I'm talking about:
I need to further subdivide these parcels into sections that ...
2
votes
2
answers
771
views
Calculating distance between points from CSV file in QGIS
I have a CSV-file with latitudes and longitudes and I should calculate the distance between the points in ascending order (distance from 1 to 2, from 2 to 3, etc.)
I tried with the distance matrix but ...
- 43
5
votes
1
answer
805
views
Automatically updating geometry attributes in QGIS without using Virtual Fields
I have a line layer and I computed the attribute "length" with the field calculator. After that, I changed the geometry of some lines with the editing toolbar. That means the values of "...
- 2,187
2
votes
1
answer
141
views
Creating points along line based on line lengths
I have a road network network (polyline shape layer) with multiple line lsegments. Each line segment has different line length as shown in image 1.
I am trying to generate points along lines based on ...
- 835
3
votes
4
answers
579
views
Measuring distance between two points on curve line in QGIS
I am using QGIS 3.10 version.
Image those two blue lines are points. How to measure the white line between those points?
- 165
1
vote
2
answers
93
views
Does SDE.ST_LENGTH() calculate the true length of arcs?
Oracle 18c/10.7.1 EGDB
I have a polyline FC that has features with arcs.
Does the Oracle SDE.ST_LENGTH() function calculate the true length of arcs?
Or does it only calculate the straight-line length ...
- 1,054
2
votes
0
answers
332
views
Calculating length along multiple line segments in GeoPandas [closed]
I would like to calculate the distance between two points. They are connected with multiple line segments. Each LineString only consisting out of two points. How do I connect these LineString segments ...
- 21
1
vote
1
answer
183
views
An application for measuring river length?
I'm aware of the coastline paradox and its application to rivers in that the measured length of a river depends on the resolution of the measurement.
Is there an application that calculates the centre ...
- 21
8
votes
2
answers
625
views
What is the maximum number of characters for a label in QGIS 3?
I am trying to determine the maximum number of characters for a label in QGIS 3. I am at over 1,000 characters and it does not display. Is there another way to display text on a map with a large ...
- 415
2
votes
1
answer
242
views
Calculating length of line shapefile using PyQGIS
I have two lines that overlap, so I clip the overlap, and I should get its length in kilometers.
The clip part is ok but I can't find any resources on how to get the length. It can be printed in the ...
- 1,209