Questions tagged [grouping]

Associating or clustering data based on common attributes or properties.

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44 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 ...
2
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1answer
17 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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16 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 ...
2
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1answer
53 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 ...
4
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2answers
96 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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0answers
46 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
42 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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0answers
21 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 ...
5
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1answer
95 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 ...
0
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1answer
67 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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0answers
21 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 ...
2
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2answers
75 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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88 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
35 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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0answers
36 views

Spatial sorting with grouping

I have been trying to do sorting with ArcGIS Pro, but wasnt able to find any features for grouping then sorting. My data has road information and I'm trying to sort segments in each particular road (...
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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 ...
3
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1answer
210 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
269 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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0answers
37 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
108 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 ...
2
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0answers
79 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
57 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
150 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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0answers
259 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 ...
1
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1answer
329 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 ...
3
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0answers
72 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 ...
1
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2answers
84 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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0answers
24 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
924 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.
1
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1answer
583 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
826 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 ...
3
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0answers
121 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 ...
1
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0answers
481 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, ...
1
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1answer
858 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 ...
0
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1answer
104 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 ...
5
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1answer
967 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)...
1
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0answers
534 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 ...
1
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2answers
112 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 ...
1
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1answer
56 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
809 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/...
1
vote
1answer
103 views

Grouping roads based on existing condition and AADT? (QGIS) [closed]

For QGIS software, I have municipality service agreement roads and an end-plan to group the roads based on close proximity (roads and communities close together or close to each other and on the same ...
1
vote
1answer
541 views

Grouping database results based on intersection using MySQL GIS?

I am using MySQL GIS (5.7.18). I have a number of locations in the database. I also have a number of other polygons (not in the database). I would like to perform a single query, intersecting all ...
1
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0answers
238 views

Use of Hot Spot Analysis (Getis-Ord Gi*) [duplicate]

I'm working with a polylines shape. I'm searching for a tool that could help me to define neighbourhoods using the values of the polylines. I have good results with Hot Spot Analysis (Getis-Ord Gi*), ...
2
votes
1answer
270 views

Group geotagged photos in MapInfo

The situation is: There are many photos (between 900 to 3000), geotagged and I can see them on MapInfo. The photos are of certain objects and there may be 2 to 8 photos for each object. These objects ...
2
votes
1answer
106 views

AcrMap- How to use the dissolve tool with large amounts of polygons?

I am a college student working on an independent research project and I am trying to figure out how many points fall within a polygon. I am examining the impacts of zoning in the Great Barrier Reef ...
0
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1answer
453 views

Clustering point data to obtain maximum count groups using QGIS?

I am working with a data set of over 3000 points which I need to cluster/group based on a distance criteria. What I would like to do is build clusters from the point data which contain the maximum ...
2
votes
2answers
194 views

Creating/extracting/summarizing data from unique values symbology using ArcMap

I am using ArcMap 10.3. I have a bunch of data symbolized by categories - unique values. I have grouped together many (10 to 40 per grouping) different values to create this symbology. Now I need to ...