Questions tagged [grouping]

Associating or clustering data based on common attributes or properties.

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32 views

Graphic grouping in QGIS Map Layout

In QGIS 3.18, I'm trying to draw symbols/graphic for Map Legend manually in the Map Layout. When grouping them, it shows the big box like the screenshot below and seems not convenient to continue ...
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1answer
46 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 ...
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1answer
56 views

QGIS - creating a report from attribute table

I create a report from attribute table. At one column I have a name of a street, at second column I have a number. Relation between street and a number is one-to-many. Is there a function to show at ...
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3answers
123 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 ...
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1answer
31 views

GeoPandas dissolve polygons based on data values

I have a long list of polygons in GeoPandas dataframe (Sample below) Index zone_name value geometry 0 A 100 POLYGON ((77.47638480859382 13.05584728590942, 77.50519132714851 ...
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42 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 ...
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2answers
140 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' thanks to @Jesse McMillan's ...
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1answer
26 views

Composite layer by distance

I've got a complicated problem right now. I have a layer with polygons and use the tool "Closest Neighbor" to find all Polygons that have a neighbor within 10 meters. That works fine, but ...
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1answer
79 views

Assigning incrementing id for each feature group in attributes with QGIS expressions [duplicate]

I have a layer with a repeating field name, thus different groups of features (I also have a numerical group field). How can I add a field group_id, using QGIS expressions? What I want is kind of a ...
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1answer
20 views

Grouping a dataframe whilst making a pie chart

I have a data layer which consists of an attribute table of ~30 columns and ~6000 rows. This table contains information about buildings that are located close to parks in Amsterdam. I want to create a ...
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34 views

GEE index image segmentation and classification

I have a code for performing an index calculation on chosen images and in chosen AOI. The next step I want to do is segment it by pixel value and classify them into 3 groups. I mean a range of pixel ...
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1answer
80 views

Group neighbouring features based on sum of attribute

Each polygon (building) contains "x" number of flats (eg "flat_num"=10 in one polygon/building). I would like to group multiple polygons if: the grouped polygons are neighbors ...
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2answers
112 views

Expression with two groups

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 id, ...
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210 views

Exporting with QPackage or QConsolidate

I know there is a similar question, but it might be dated, and didn't completely answer my question. I know of two plugins to export your QGis project, QPackage and QConsolidate. I'm not very familiar ...
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1answer
49 views

Find Largest Building in each Parcel (largest feature in each groupby set)

I have a question similar to this one, but the proposed approach doesn't seem to work. For context, I am new to qgis. Given a set of parcels, each with 0 or more buildings, I want to select only the ...
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26 views

Creating polygons from open ended line (riverine) feature

I have a dataset of rivers which I'd like to build into polygons of areas enclosed by rivers. The rivers are continuous lines but there are open ends. Is this possible? It's OK if the calculated ...
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1answer
103 views

Copying all visible layers to new group

I would like to copy all visible layers in a project to a new group. Does anyone know of a quick way of doing this? Background: We have a Project that acts as a library for all the spatial data we ...
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1answer
79 views

Large-scale cloud masking, grouping and mosaic in Descartes Labs platform

I am looking to create a stack of cloud-free sentinel-2 imagery by day for a large portion of California for all of 2020 in the Descartes Lab platform. I realize that this is a very large amount of ...
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24 views

Using a postcode sector map with a population attribute, create clusters of those sectors to have a total population within a defined range

I have a postcode sector map in QGIS and one of the attributes is 'population'. I am trying to create a map showing what postcode sectors would need to be clustered together in order to split the ...
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2answers
77 views

Merging attributes of point features at same location

I have a CSV-file with all the facilities in an area, some sites have multiple facilities so at some locations there will be multiple points e.g. sports hall and swimming pool. Is there a way to join ...
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138 views

ArcMap - error 000728 field does not exist within table

I'm trying to join the table from Excel (my calculation about one region in Poland) to my shapefile (which contains whole Poland map and different calculations, so I need to attach a new table to be ...
2
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1answer
43 views

Categorizing attributes by keyword in new field with field calculator in QGIS 3

So, the geological classification shapefile of the Philippines has the 'DESCRIPT' field which contains the geological time scale of each feature. "Oligocene-miocene" and "Oligocene-miocene (igneous ...
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38 views

Calculate frequency based on a filtered field, and put the value in another field

I'm a python beginner. I'm working on one feature class, i would like to group this feature based on group_ID field, and then for each one of this group i would like to calculate the number of rows ...
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1answer
286 views

Centroid of multiple polygons based on value in attribute table

I have a (polygon) shapefile with multiple zones. Now, I would like to calculate the centroid of groups of these zones. The zones have to be grouped based on a value in the attribute table: AreaNr ...
2
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1answer
367 views

QGIS - SQL GROUP BY and MAX

I have a layer which contains a unique ID (UID) for each feature and another column of Scores. For example: UID, Score A12,1 A13,1 A14,4 A12,2 A13,3 A14,5 I would like to use an SQL statement to ...
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39 views

How to make analyzeGPS distanceGPS group by trip?

I have a dataset with id, lat, lon and time, where each trip has a unique id. When I try to use mutate with the distanceGPS function in the AnalyzeGPS package and group by trip using this code: gps%&...
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2answers
121 views

Finding number of days per ID in table using ArcPy?

I need to count the span of days an individual has been observed, from the first til the last observation day. There can be many observations per ID per day and not everyday has observations, hence ...
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0answers
96 views

Grouping layers by attribute value and finding nearest neighbour using QGIS?

I am new to QGIS. I have two layers (layer_a and layer_b) consisting of two sets of points. If I want to find the nearest point in layer_b for each point in layer_a, I can just use the Distance ...
2
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2answers
59 views

Update 1 random value in a group of values

I have an attribute table with a date field and a random field. The date field has three different times for each day. I need to input a '1' in the random field for one of those three times in each ...
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2answers
176 views

How can QGIS 3.X create atlas by a group field?

I have a line layer with 8 features and a field TYPE (5 features is type_A and 5 features is type_B). I want to create a atlas which output is two single image (one is grouped by typ_A with 5 features,...
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319 views

Leaflet markers at same geo location (ClusterGroup)

I have a map created with leaflet with different markers. Sometimes the markers have the same (1:1) geo position. I have already tested the great addon clustergroup, but I need the function to be ...
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1answer
384 views

Group by variable and create layers from that in QGIS [duplicate]

I have a large shapefile with one layer with several variables. The shapefile has US block groups that I'll use for analysis. However, as I want to use this for leaflet, I would like to create ...
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74 views

Clustering based on eqaul populations

I have a map of a city that is divided into 65 sectors (building lots in purple, sector boundaries in red): In my shapefile of building lots, I have an attribute that is the total population within ...
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2answers
85 views

Selecting features from grouped shapefile

I have downloaded some glacier outlines from the GLIMS database (http://www.glims.org/maps/glims) as a SHP file. This contains multi-temporal data, that is, more than one outline per glacier (more ...
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27 views

Grouping overlapping points by UTC Time, sum and average?

I have data from airplane calibrations where the plane flies in a crossing pattern; i.e. going E->W and W->E, then N->S and S->N. I need to sum and average the values for both flights in each ...
6
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1answer
1k 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.
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1answer
686 views

Get child layers from a layer group

I'm using a geoserver and openlayers3 with html. I cannot find the way to obtain the child layers from a layer group. I have a layer group, and I show it in html perfectly, but what I want is to be ...
2
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2answers
923 views

Replace several coordinates by its mean value grouped by multiindex Pandas

I have a table with some info that are getting by a GPS, in my table I have this structure: Date Time Latitude Longitude Accuracy Weather Visibility ViewPoint Species Bearing ...
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0answers
124 views

Grouping neighbor points based on field sum in QGIS

I have about 14,000 points. These points have a specific field "time", an integer value, mainly between 1, 2 or 3. I would like to split these 14,000 points into groups based on the "time" field ...
2
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0answers
504 views

Group by index column, compare area and add values to new column in Python?

I have these columns: index, area_of_poly, cad_admin I have to group by index (it is a normal column called index) in order to take the rows that have the same value. #all the ones, all the twos, ...
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1answer
1k views

Extract and sort x coordinates in groups from a column to a new one in geopandas?

I am working with geopandas There are these columns:geo,cat and I have to make the new column called rank. rank should contain according to the groups with the similar cat number an increasing ...
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1answer
122 views

Filtering out clusters of features based on collective area threshold using QGIS/python?

I have a map I generated that roughly estimates timber industry land ownership (designated by the green on the map) in the counties surrounding the Salish Sea in the US state of Washington: I want to ...
6
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1answer
1k views

r - Can dplyr::group_by work with sf::st_intersects

Trying to combine dplyr::group_by and sf::st_intersects to see which of the objects within groups in a sf dataframe are intersecting with each other but in the end all objects are compared with all ...
3
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3answers
1k views

Creating population dot density map at the block group level in QGIS

I'm new to QGIS, always used ArcMap, and I'm struggling to find out how to best display population density at the block group level for a county (the most granular level of detail for census geography)...
2
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0answers
579 views

Clustering points into *n* number of groups of equal counts with ArcGIS

I have to divide points into groups. These groups will be used by agents to talk to property owners. The goal is to make the agent's job easy by grouping parcels that are near each other together, as ...
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2answers
125 views

How to cluster/group points based on their frequency and event time without overlapping them?

I am trying to group around 100 points based on their frequency and occurred month (similar to https://i.stack.imgur.com/i7Mzi.png) but I haven't found a solution yet. Tried many tools in QGIS but ...
19
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1answer
4k views

Is it ok to group by geometry in PostGIS?

Is it OK to group by geometry? We do a lot of counting points by polygon geometries, which involves intersecting the data first in order to count instances of students. by school boundary, block ...
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1answer
58 views

Reducing the number of records

I have a very extensive GPS track from which I am trying to reduce the number of plotted points. I though that I would be able to do so by grouping by a round of the timestamp /900 ( every 15 mins ), ...
4
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0answers
2k views

Clustering of events within a space-time window (R)

I am relatively new to clustering methods and am trying to determine the best method for clustering (or merely grouping) events that fall within a space-time window using preferably R. My goal is to ...
2
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1answer
915 views

Load Named Style within a group on QGIS

I am trying to apply the style from .qml to a group of layers in QGIS. I have tried to incorporate LoadNamedStyle within jkall's code here: https://github.com/jkall/qgis-processing-scripts/blob/master/...