Questions tagged [aggregation]

To combine data into larger units. For example a group of points to a polygon, or political subdivisions (provinces) to larger entities (country).

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PostGIS/PostgreSQL Heavy performance issues with SUM

Not sure if this is specific of GIS stuff or simply a SQL performance issue, but due to the nature of the issue and that I am working with H3 data types here it goes I have a query that runs very ...
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Unexpected resolutions when aggregating rasters with raster package in R

I have a (near) global raster of elevation data in WGS84 with a resolution of 0.00893153 x 0.00893153. I am trying to aggregate it to a resolution of 0.166667 x 0.166667 with the following: fact = 0....
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Resampling high resolution binary raster

I have a large, high resolution raster of binary data that I need to reproject and resample to align with a lower resolution dataset. Because the original data is binary, I need to aggregate using the ...
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Aggregating vector grid tiles to lower resolution in QGIS

I have a vector layer with grid tiles of 100x100 meters that contain data for each tile. I now would like to aggregate those tiles to a lower resolution (e.g. 200x200m, 1000x1000m), preferably in QGIS ...
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Polygons with same geometry and bbox but can't be aggregated with GROUP BY

I'm trying to create a constraint unique on a geometry column to avoid duplicate ones, following https://dba.stackexchange.com/questions/299098/why-doesnt-my-unique-constraint-trigger/299107#299107 ...
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Aggregate interpolated data at county level with R

The raw data is at the state level and I would like to go down to the county level. To do this, I first adjusted the data to county level and then interpolated it. The raw data on state level looks ...
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Geometry simplification for large scale aggregations in GEE

When aggregating on a large scale in GEE, does geometry simplification matter? For example, when aggregating climate data on 30 km/pixel (e.g. NEX-GDDP), does it make computational sense to change ...
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4 votes
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Aggregating features values based on distance in QGIS

In a polygon dataset, I try to summarize values of surrounding features based on a minimum distance if their area is too small (e.g. 500 square meters). For example, I have 3 polygons with 300, 250 ...
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Determining scale for spatial aggregation based on precision of lat lon coordinates

I need to retrieve terrain attributes from DEM such as aspect and slope representative for a point coordinate. I have realized that the coordinates that I have might be too coarse to make a meaningful ...
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Aggregating data by zip code over time in QGIS

I have data that is at the zip code level and I am looking to be able to have that data aggregate over time with a temporal display of the map. Is there a way to do this using QGIS?
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Get the sum of an attribute within a set radius for each row using GeoPandas

I have grid map that contains cells. Each cell is represented as a row in the dataframe, and each row contains the average population "pop" attribute. What I need is that for each of these ...
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Getting median value of attribute for duplicate polygons and dropping duplicates using GeoPandas

I have a DataFrame that resulted from spatially joining a digital elevation map with a square grid map. This unexpectedly resulted in duplicate rows where two rows will have the same "geometry&...
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Merging zipcodes based on population to create larger areas in QGIS

In QGIS I have a shapefile with small geographic areas (zipcodes) with population in each zipcode area. Currently the population per zipcode vary very much, some as low as 1 person living in them. I ...
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Merging touching polygons in same layer using ArcMap [duplicate]

I have a shapefile consisting of many polygons, and I would like to merge them when they touch each other (see red lines below). I've been trying quite a few tools in ArcMap 10.7 such as Dissolve, ...
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Why does aggregation of MODIS pixels not sum to 1?

I want to find the fractional cover of different tree species from MODIS (30 m resolution). I use R to stack, aggregate (1020 m resolution) and thereby find the fractional tree species cover for a ...
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Aggregating and calculating fractional vegetation cover from raster using R

I have some MODIS data on vegetation cover. It is at a 250 m resolution and I would like to aggregate the pixels on a 1 km scale, and at the same time calculate the fractional vegetation cover since I ...
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2 votes
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Dissolving linestrings by uniqe value in field using QGIS

I want to dissolve a line geometry by a unique value in the field "RoutenIDs". For example dissolve line 37 to 43 with value 27. Dissolve line 37-46 ... with value 1999 and so on. Is there a ...
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Creating polygon which outlines many smaller polygons to show their extent using ArcMap

I am looking at a wildfire, and I need to display the wildfire footprint, however all I have is a raster of classes, I converted that raster to a polygon for values that show low to high burn severity,...
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Customizing factor in aggregate tool in ArcMap

I have a raster of 30m cell size, with either value 0 or 1. I try to aggregate this into a 1000m cell size. I can then see the proportion of '1's, in a 1000m cell size raster. But the Aggregate tool ...
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3 votes
1 answer
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Aggregating MultiPoints to MultiPoint output using ST_Collect

I have a geometry column that stores MultiPoints. How can I aggregate MultiPoints having another MultiPoint as a result, not a GeometryCollection? select st_collect(geom), id from my_table group by id ...
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6 votes
2 answers
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How to group polygons based on spatial proximity and field value?

I have a shapefile consisting of the day of the year on which the temperature in a lake exceeds 15 degrees Celsius. I can see clear patterns in this (here seen as a raster): I want to group the ...
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Aggregate polylines in JavaScript (Leaflet)

After executing a certain amount of routing calculations, I have a list of vehicle routes as shown in the image below. Now I have added an opacity to these lines to visualize the frequency of certain ...
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1 answer
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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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2 votes
1 answer
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PostGIS: Aggregate small raster to larger raster

I am just getting into rasters in PostGIS and I have stumbled across a problem I can't solve: Given one large raster A (e.g. pixel size 5km x 5km) and one smaller raster B (e.g. 1km x 1km) which might ...
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Sum/aggregation of polygon's values within other polygons using dyplr

Let's say you have two sf objects made of polygons. In my case, one is administrative units (ADM) and the other is buildings (SHAPES). I would like to calculate the sum of the surface area of SHAPES ...
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ArcGIS - Percentage in Census tract to HUC

I’m trying to figure out the percentile of demographic value (minority %, poverty %, etc.) per watershed at HUC12 level. I was hoping that I can somehow convert the values from census tracts into HUCs....
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5 votes
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In QGIS my expression aggregation in attribute forms slow works

There are two layers: Parcels and Parking. Parking has attribute: parcels_objects, this is lists of parcels intersect of parking. When I create a parking object, I want to calculate all parcels ...
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ArcGIS Pro - Clip (Modify Features) aggregates nearby geometry

I have a large polygon that contains several several other (smaller) polygons. Some of these smaller polygons also intersect with each other but they all at least 'touch' the larger polygon. I want to ...
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4 votes
2 answers
318 views

Aggregating point data into polygons using QGIS

I would like to aggregate point statistics to a specific polygon layer which is a 100*100m raster. The point dataset includes address data of buildings and their heating energy consumption. So the ...
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2 votes
1 answer
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Counting categorized points in polygons using PostGIS

I want to do an operation i PostGIS similar to the count points in polygon in QGIS. I have A multipolygon table (plan.polygon) consisting of several areas A point table (basemap.points) in a PostGIS ...
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3 votes
1 answer
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Relation aggregate function error in QGIS using Geometry by expression

I have a point layer, consisting of 12 points with fid 1 to 12. I want to render points with fid > median (fid) - thus in this case, point 7 to 12. That works perfectly if using geometry generator ...
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3 votes
1 answer
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Creating polygons based on point layer using QGIS

I have a point layer of residential coordinates which includes an attribute field indicating the most visited hospital for the people living at the coordinate. From these data, I want to create a ...
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2 votes
0 answers
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Pie charts in QGIS: attributes generated with Expressions not working when using aggregate function

I have a problem to add values generated by expressions with aggregate functions to pie charts (see the screenshot below for better understanding). This question is a follow up question to this one ...
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4 votes
2 answers
61 views

Build land classes from GIS data

I have combined geo-referenced terrain, climate, and soil data with the requirements of the different agricultural food crops in order to build land classes that tell you where which crop can be grown....
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2 votes
1 answer
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PostGIS: Creating Polygon from lots of other geometries and then returning list of ID's in the same query

I am fairly new to all of this but in simplistic terms I have the following problem: I need to create lines from points, and from said points group all of those within n distance of one another. From ...
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2 votes
3 answers
223 views

Label sums of surfaces grouped by common attribute values

I want to label the sums of surfaces ("Groesse") grouped by common attribute values ("Block") in QGIS 3.16. I need one label for each group. The following pictures help to describe ...
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1 answer
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Aggregate tool in ArcMap fails

I created vector polygons from a raster image and now I want to merge adjacent polygons based on a distance. I used the Aggregate Polygons (Cartography) tool after smoothing and running a Repair ...
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0 answers
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Converting protected areas polygons into raster

I am working with protected areas for vulnerability analysis, I have values of 1 for protected areas being vulnerable, and 2 to non-protected areas being less vulnerable. I have transformed this into ...
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3 votes
1 answer
151 views

Creating aggregate attribute from two polygon layers

I have two layers: one underlying land use information layer (with columns "land_use_type" and "area") and one for leased land. To organize the leasing of the land it would be ...
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3 votes
2 answers
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Calculate focal statistics from a 10m raster to populate a 1km raster, using the 1km raster to define the window?

I have a binary raster (1-0), cell size = 10m. I would like to generate a 1km raster, where cell values equal the mean value of all cells within a 3 km radius. I know I can use focal statistics to ...
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2 votes
2 answers
87 views

Group geometries of line data based on one common attribute and compute length

I have a vector file of river networks in QGIS. Some of the rivers are split up it multiple rows. What I'd like to do is to aggregate the rivers based on the attribute in one column (S_NAME) and ...
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2 votes
0 answers
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Aggregate polygons into specific shapes [closed]

So, I've basically got what amounts to a vector-based raster set. It's a series of regular-sized squares that, for all intents and purposes, are raster pixels. The only reason it isn't a raster is ...
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2 votes
1 answer
1k views

Spatial join and sum aggregation of two polygon GeoDataFrames in GeoPandas

I would like to join two GeoDataFrames with polygon geometries (purple and green, see screenshot below). However, I would like to get the sum of all intersecting green areas per purple feature they ...
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1 vote
0 answers
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Aggregating data and displaying counts with GeoPandas

I have two datasets that I want to use. The first is a shapefile of King County that has polygons broken up by school districts. It has boundaries saved as polygon features on a geo-dataframe. The ...
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0 votes
1 answer
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Using Spatial Join, Dissolve and Aggregate in ArcGIS Pro ModelBuilder

I am creating a workflow using ModelBuilder in ArcGIS Pro 2.5.2 that will take updated parcel polygons and create/update the Zoning_Parcel (parcels symbolized at the parcel level) and Zoning_Districts ...
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0 votes
1 answer
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Aggregate number of features by country in Overpass

Does Overpass (or Overpass Turbo) provide a mechanism for query like “show me the number of nodes tagged foo=bar by country”? Output being something like this: Country Count Estonia 5 Latvia ...
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6 votes
0 answers
233 views

Getting layer id of processing step in QGIS graphical modeler for usage within aggregate() function

How can I get the layer name or layer id of the result of an processing algorithm within QGIS graphical modeler, so I can use aggregate() function in a later processing step? Is this somehow possible ...
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1 vote
0 answers
168 views

Sum area of features intersecting atlas feature in QGIS

I have AOI layer named "Clusters" which is set as the Atlas coverage layer for my project I want to sum the area(Hectares) of specific intersecting features from my "...
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2 votes
3 answers
507 views

Using PostGIS to generate a polygon representing the area shared by some (but not all) of a set of polygons

I have an application where several users submit polygons, and I am looking to create an aggregate polygon that represents a kind of average of their submissions. We use PostGIS for our spatial ...
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1 vote
0 answers
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Creating a new vector by aggregating another vector's value with a specific criterion in QGIS

I have a vector polygon layer in which each polygon represents an olive grove, each polygon has the data of harvestable biomass in that specific olive grove. Now I have to estimate transport costs ...
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