All Questions
152 questions
0
votes
1
answer
73
views
Summing up values of polygons within bigger polygon in QGIS
I have buildings as polygons with a lot of data in the attribute table. My goal is, to sum up the values selected for a table column of all building polygons within the building blocks (here in purple)...
- 745
2
votes
2
answers
96
views
QGIS Dynamic filter based on the names of layers visible within a group
I'm not sure if this is even possible in QGIS, but I try to filter features in a layer based on the names of visible layers within a certain group.
Example:
I have a group holding layers named by ...
- 97
2
votes
1
answer
84
views
Creating autoincremental ID for groups in QGIS
I have an attribute table containing information about area, region, and samples. The table structure resembles the example shown below:
My goal is to automate the generation of "ID"s when ...
- 518
2
votes
1
answer
94
views
Grouping points within counties and symbolizing their data as pie charts in QGIS
I need to combine/categorize points within different polygons while retaining some of their values. I've made up a scenario to try and simplify my problem.
The layers I have to work with are:
a point ...
- 29
2
votes
1
answer
86
views
Aggregate/group points by value, and label aggregated point with aggregate expression (QGIS)
Problem Statement
I have a layer of multiple points, and I am trying to:
Aggregate/group the points by their attribute values, so that one point is drawn for each group of points with matching ...
- 135
3
votes
1
answer
160
views
How to group/clean group of scattered points based on their distance and attributes?
I downloaded traffic signs from Mapillary API. I found that many of these points represent the same real life entity, but they are scattered in the map. Since they are distinguished by their category ...
- 645
3
votes
2
answers
252
views
Classifying in QGIS into arbitrary number of percentiles instead of quantiles, based on attribute field value
Extending this question and this one: In QGIS, there are special expression functions for the first and third quartile (q1 and q3) and as well as median (median). So it's easily possible to categorise ...
- 75k
3
votes
2
answers
658
views
Create multiple callout lines from a single label
I would like to label groups of points (clusters) with only one label but several call-out lines. I built on top of the very appealing answer from @eurojam here: Giving one label to two points using ...
- 366
0
votes
0
answers
87
views
How do I create a Geodataframe which the data is grouped by User ID & the timestamp is sorted from oldest to most recent?
I've been struggling to complete this exercise (Exercise 2 Problem 3) which you guys can refer to this link. A reminder that the kruger_points.shp is obtained from Exercise 2 Problem 2. Here's the ...
- 47
0
votes
0
answers
77
views
Creating non-overlapping boundary polygons with point attributes
I have a set of points that represent the meter locations for my electric company. These points contain a 3 digit code that represents the route number for the meter reader routes. I also have a ...
6
votes
2
answers
417
views
Categorising data points along transect using QGIS
I have data on the latitude and longitude of several locations in Europe (blue). So far I have been able to read this data into QGIS but not more. I would like to plot a transect (red) and then ...
- 71
5
votes
2
answers
572
views
Calculating mean with group by based on another column in QGIS Field Calculator
I have daily temperature data for several cities from January to December.
I'd like to calculate the average temperature per month for each city in a new column.
I have a column "city", &...
- 665
5
votes
1
answer
210
views
Selecting N points within each geometry using SQL
I have grid and point tables in my Postgres db. The points are not equally distributed over the grid. The grid table is 100k+ geometries and the points are in the 100's of millions so efficiency ...
- 1,653
6
votes
3
answers
1k
views
Grouping points to clusters containing similar number of features using QGIS
The question
Using QGIS, how to cluster unevenly distributed points from the same layer to groups of about the same size / containing the same number of features?
The problem
I have a large point ...
- 75k
3
votes
1
answer
110
views
What is the equivalent of native:aggregate() in QGIS Field Calculator?
I have two layers which I want to connect using the aggregate() function with the Field Calculator. I can do this using the processing tool:
processing.run("native:aggregate", {
'INPUT' :...
- 477
0
votes
1
answer
107
views
PostgreSQL and extension tablefunc with enumerated type
In PostgreSQL,
I created an enumerated type
CREATE TYPE w_sebio.t_sebio_type_sad
as ENUM ('transféré', 'traité', 'non soumis', 'ouvert', 'non traité','PAC réalisé');
then a table
CREATE TABLE w_sebio....
- 1,015
2
votes
2
answers
145
views
Looking for QGIS equivalent of ArcGIS "Group values" tool
I have LULC 8 classes. I want to group them in QGIS into five priority score classes in Symbology, just the same as the function in ArcGIS "Group values". But I can't find the same tool in ...
- 175
0
votes
1
answer
89
views
Count number of records with the same date
I have a table with species sightings and I would like to add a field with the sighting number in that day (every day should start again from number 1). Ideally this should be done automatically as I ...
- 33
2
votes
1
answer
375
views
Get a group from layerTreeRoot using its unique id using PyQGIS
I am having trouble when loading some layers in QGIS. I want to place them in specific groups and sub-groups but a problem occurs when multiple groups and sub-groups have the same name. The only way I ...
0
votes
1
answer
263
views
Hiding/Displaying dashboard content (tiles) based on user or group logging in using ArcGIS JavaScript API
I want to know if it is possible to either hide or display the content of an Esri webapp, dashboard, or experience (tiles, widgets, data layers, filters) depending on which Portal user is accessing ...
- 1
1
vote
1
answer
99
views
Cannot enable 'Any organization's members' setting when creating Group or updating properties using ArcGIS Python API [closed]
I am creating a group using the ArcGIS for Python API, there is limited information in the API Reference here.
And I found some more information in the Rest Reference relating to the membershipAccess ...
- 1,745
0
votes
2
answers
968
views
Sampling points in R with both distance constraint and group
I have a spatial point data frame with categorical variable as a column named "type", I would like to draw a random sample from these points (let's say 100 points) with maximum and minimum ...
- 606
2
votes
2
answers
2k
views
Filling attributes in one field based on second field with same values in QGIS
How do I fill the attribute with "SID_2" of the captured image where the ID of "SID_1" is NULL?
I'm using QGIS 3.22
- 29
4
votes
2
answers
807
views
Area of each polygon that intersects another layer and total area of intersections in QGIS
I have two layers: 'A' (orange) and 'B' (purple).
Using a Virtual Layer and group_concat I am able to list the polygons in layer 'B' that intersect with those in layer 'A'. I found that solution at ...
- 119
1
vote
0
answers
183
views
Group by multiple columns in QGIS array
I'm looking to create a figure with multiple rule-based symbologies. A graduated range within a category within a main category.
The only way I think that's possible is by adding categories, ranges to ...
- 11
8
votes
4
answers
2k
views
Adding unique ID for groups of items using Field calculator in QGIS
I have a set of string values in a shapefile's attribute column and want to assign a number to them in a way that each unique string gets an integer number, like this:
How do I do this using the ...
- 125
4
votes
1
answer
75
views
Grouping features with identical values in two fields and deleteing the geometry with the lowest value in the third field using QGIS
I've got a shapefile with three fields: "X", "Y" and "Z" they are the geometries as well but I also have them as field values.
Every line geometry in the shapefile has a ...
- 41
1
vote
1
answer
46
views
What do parameters provider_group_name and provider achieve in GroupManager create function when using ArcGIS Python API?
The create() function in the GroupManager module has two parameters; provide_group_name and provider.
See API Reference
What is the purpose of these parameters?
I cannot find any documentation ...
- 1,745
6
votes
3
answers
1k
views
Calculating Convex Hull based on attributes in QGIS
I have a layer with lots of (spatially grouped) lines - lines belonging to a group share the same value in a field.
I would like to create convex hulls around each of these groups using QGIS 3.8.
I ...
- 73
5
votes
1
answer
1k
views
Unsplitting/merging lines that have coincident endpoints using PostGIS
I have a large dataset of lines/linestrings (ie. a road network), which is unregularly segmentised/ split and the lines needs to be merged at coincident endpoints (if only two lines are touching). I'd ...
- 163
3
votes
2
answers
813
views
Summarizing fields with same ID in QGIS Field Calculator
I am looking for a command, that sums the value of the field "Baulast" if they have the same "ogc_fid" and if there is a Number in the field "WEA". If there is no number ...
- 327
0
votes
0
answers
80
views
Mapping groups' data on the map using Map.addLayer - GEE
I wanted to extract the areas of specific clusters. I asked this question. I wanted to extract the areas of object-based clusters but the answer I got, resolved my issue. I need to visualize the ...
- 25
2
votes
1
answer
51
views
Combine features into new category
Within a vector layer I have dissolved 25k polygons into 43 different categories of land ownership (Ld_Use_Des). But now I want to further ''group'' them. For example I want to select Mineral Rights ...
- 635
4
votes
2
answers
497
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
6
votes
2
answers
326
views
Counting fire occurences per county per year using QGIS
I wish to loop through this shapefile, and for each "COUNTY_NM", count the number of values corresponding to each "layer" value.
I want to output a CSV or equivalent which would be ...
- 199
3
votes
2
answers
796
views
Adding unique ID for consecutive groups using Field calculator in QGIS
I found a similar question on this site and the answer suggested:
array_find(
array_distinct(
array_agg("PortCluster_ID")
),
"PortCluster_ID"
) + 1
...
4
votes
1
answer
229
views
Calculating two columns at once in QGIS
Is it possible to calculate two columns at once?
So what I mean is that we have different covers and lengths and I want a total length of "Cover A" after that a total length of cover tb and ...
- 41
1
vote
2
answers
184
views
Assign ID for coordinates with several points
In ArcGIS pro I have a point layer with XY-coordinates. At each coordinate there are several points with different timestamps. I would like to give each coordinate an ID, for example to be able to ...
- 33
6
votes
2
answers
1k
views
Summing area of by several attributes in QGIS
I have a shapefile that contains building footprints with multiple addresses with different functions (with each an usable area). I would like to calculate the sum of the usable area, per building &...
- 261
2
votes
0
answers
56
views
Create variable containing the conditional mean of a group
I have a table with three columns, the first defining a group (Group), the second a characteristic (Species), and the third a numeric value (Height). I would like to obtain a fourth numeric column in ...
3
votes
3
answers
971
views
Counting and merging features based on attribute field in QGIS
I have a shapefile with a number of features, each with a field called "region". I want to count the number of features corresponding to each region. Outputting a shapefile with one feature ...
- 199
1
vote
0
answers
120
views
Using function "buildGeometry" of JavaScript library JSTS with 'ol.interaction.Select' and 'ol.Collection.<ol.Feature>' objects?
What type is the argument of a function "buildGeometry" of JavaScript library JSTS? How to use JSTS function "buildGeometry" with OpenLayers 3 selection, which is created is this ...
- 11
2
votes
2
answers
276
views
Selected item in layertree group or layer?
How do I check in PyQgis if the selected item in de QgsLayerTree is a group or a layer. I really can't find the answer.
- 495
5
votes
3
answers
452
views
Generating unique code for features via grouping by several attributes
I have features with 3 columns of information ("material", "name", "dimension") in the Attribute table. I need these features to group - to create 4th column where ...
- 415
9
votes
1
answer
3k
views
Creating Groups of points based on proximity in QGIS?
I have a dataset with around 900 points and I want to cluster them into groups of 44 based on proximity.
Is this possible in QGIS?
I have tried to use the convex hull tool with no success.
- 91
0
votes
1
answer
3k
views
GeoPandas TypeError: geometries are not orderable (numpy: TypeError: '<' not supported between instances of 'Point' and 'Point')
I'm trying to group rows of a GeoDataFrame based on a common gid value and aggregating two columns for which the values differ but I am facing this error:
TypeError ...
- 10.9k
4
votes
1
answer
157
views
Grouping lines by name and determining their proportions using Virtual Layer
I have a line layer with hiking trails. The hiking trails are divided into their surfaces. So one hiking trail consist of parts with different surfaces.
I would like to use a virtual layer to group ...
- 8,406
2
votes
0
answers
198
views
Group points based on proximity and equity using QGIS
I would like to group students based on the nearest school, but also having mixed social categories within the group of students.
I have x,y coordinates for the students and the shcool.
Each student ...
- 31
1
vote
1
answer
910
views
Rename layers within group automatically by adding a prefix derived from group name using QGIS
I have some Sentinel derived rasters (time series) divided in tiles. In my QGIS (3.16) each tile is represented by a group. Each group contains rasters from different dates and according layernames. ...
- 507
0
votes
1
answer
539
views
Joining tables with GROUP BY in ArcGIS Pro
I have a layer "Table1" and an attribute table "Table 2" both stored in a PostgreSQL enterprise geodatabase, these 2 data have one field in common for which the cardinality of the ...
- 183