Associating or clustering data based on common attributes or properties.

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2answers
52 views

Clustering geographical data based on point location and associated point values

Given data points with longitude, latitude, and a third property value of this point. How can I cluster points into groups (geographical sub-regions) based on the property value? I searched by google ...
3
votes
1answer
33 views

Get the full list of commons

In QGIS I've loaded the shape file "province" in which attribute table contains 242 fields (the municipalities of this province) and also two other files downloaded from openstreetmap about hotels ...
4
votes
2answers
68 views

How to group by attributes and give unique categories in QGIS?

I have features and each of them has an attribute about what it is. In my case, I have points representing trees and each tree has its species name as an attribute. I would like to group them by ...
1
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1answer
25 views

Identify groups of stacked geometries in PostGIS

I need to create a column in my PostGIS table with values identifying different groups of stacked/duplicate geometries, such that one group of stacked geometries might get a value of 1, another group ...
2
votes
0answers
41 views

How to cluster point data into equal sized groups [closed]

I need to cluster point data into equal sized groups. I have 180 points and want to create 3 groups each containing 60 points. The groups should contain points which are close to each other. Is there ...
5
votes
0answers
99 views

Finding density centroids within polygons in PostGIS

I want to find the highest density of OpenStreetMap nodes within a dataset of census geometries. I want to tie the census data to the location of the node which is most central in terms of population. ...
1
vote
1answer
40 views

Using FME to aggregate POI to one point

I want to aggregate points of interest (POI) using FME. The aggregation should make it possible to group all POI within an area based on a buffer distance from the centerpoint of n POI. This would ...
2
votes
0answers
104 views

Merge n number of adjacent polygons [closed]

I have over 17,000 individual polygons. I want to merge two adjacent polygons so that I finish with approximately 8,500 polygons. The polygons need to be merged based on location, merge two adjacent ...
1
vote
1answer
92 views

How to Group or Cluster Points that are within 45 miles of each other? in ArcGIS?

I have a project in ArcGIS (ArcMap 10.2) where I want to identify naturally occurring dense spots of points and then form groups in that dense area, where points are within 45 miles of each other. ...
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0answers
37 views

Locating Multiple Points on Mutlipes routes by a Unique ID

I'm trying to get a "MEASURE" for Points along a route. I need ARCGIS10 Desktop Linear Referencing tools or other application to use a unique identifier to match the Lines in the route to points ...
1
vote
1answer
161 views

How to get sum / total length of lines per polygon in QGIS?

I have a line vector layer which has multiple segments within individual polygons in a separate polygon layer. I have spatially joined the attributes so that each line segment now has the same ID as ...
1
vote
1answer
87 views

How to merge two point feature classes based on spatial location using ArcPy?

I have two point feature classes, each containing about fifty points. These 2 point feature classes should be merged, or the points of feature class 2 added to feature class 1, as feature class 2 does ...
2
votes
1answer
86 views

Grouping points using grouping analysis to look at raster characteristics within overlapping buffers?

I want to extract averages from raster data that fall within buffer zones around a village point. The problem is that the villages are pretty close together in some places and I need to come up with ...
5
votes
1answer
169 views

Dividing polyline layer in clusters with specific requirements in ArcGIS for Desktop?

For my work in ArcGIS 10.2 for Desktop I need to divide line layers into clusters/groups. Currently I am doing this manually, but I like to automate this. The line layers can consist of 50 up to 2500 ...
1
vote
1answer
173 views

Group attribute tables values for use with conditionals - Python

I would like to group values in a field in an attribute table. The field contains duplicate values. These duplicate values should be grouped based on duplicate values, the field would look something ...
1
vote
0answers
48 views

How to join points into overlapping polygons layer?

I'm using QGIS and I am relatively new to it. I have a points layer. Each point is the location of a conflict event and the attributes are the type of conflict, year of the event, number of deaths ...
2
votes
3answers
93 views

Dissolve without removing interior lines in ArcMap? [duplicate]

I'm fairly new to GIS and I'm having an issue that I hope someone can help me resolve? Basically, what I'm trying to do is merge features based on a single attribute so that my table no longer ...
1
vote
1answer
167 views

Grouping points based of user-provided distance in ArcGIS for Desktop?

I have a point layer and I need to group/aggregate the points within a 1km proximity into 1 single point to create a new point layer. I was trying to use Aggregate point and then Feature to point, ...
3
votes
1answer
402 views

How to group by a category and sum multiple variables within that category using QGIS?

I'm using QGIS for some analysis. I have data in this format: Name is a text variable and categories are all integers And I want to generate a sum for all categories for each name, ie a table like ...
3
votes
2answers
120 views

How to map a building to only one grid which contain more than half of its area using qgis?

I have a shapefile of a city map and I have created vector grid as polygons. After intersecting the two shapefiles, a building will map to all the grids it overlaps. However, if I just want it to ...
1
vote
2answers
315 views

Headings in legends

Is there a way, in the legend, to get the headings to stretch across multiple columns? For instance I have a layer with multiple attributes that are being displayed (in the example... fire hazard ...
0
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0answers
83 views

Grouping Features by Proximity

I have a layer with 12,000 hotels across the US and I would like to put them into groups of 2 based on proximity. Each hotel would be in only one group with its nearest neighbor optimizing for the ...
3
votes
1answer
188 views

GROUP BY on geography in postgres 9.4.0 returns wrong/different results

table definition: CREATE TABLE search ( id bigserial NOT NULL, location geography(Point,4326) NOT NULL, location_aggregated geography(Point,4326) NOT NULL, created timestamp with time zone ...
4
votes
1answer
605 views

postgis: cluster/group points based on distance

We have a set of thousands of points and want to group all of those which are within 100m distance from each other (to get the centroid from each group). A first idea was to build 100m buffers around ...
0
votes
1answer
248 views

Create certain number of Clusters, equal sum of Z value

Divide polygons into *n* number of groups of equal counts with ArcGIS 10.2 is very similar to my question. But instead of equal number of polygons, I have multiple points (schools) with a z value ...
2
votes
1answer
179 views

Difference between: join, merge and group

Suppose it is desired to make polygons A and B, and their respective attributes to be one unique polygon C. What is this GIS operation called? Is there any difference in GIS terminology about ...
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0answers
97 views

Reclassify weighted sum values

I have using weighted sum to find areas to plant trees. The values I get out by using weighted sum are 0.7-0.9 in floating point. I want to be able to reclassify this layer so I can then use region ...
7
votes
0answers
243 views

Grouping carpool participant addresses for network

I have a list of addresses of people participating in carpools to a workplace and a list of cars given by the workplace. Both lists change daily. I need to group people by their addresses and assign ...
2
votes
1answer
424 views

How would I group values in a field based on range of number using python, and then update the attribute table?

An example of what I'm trying to accomplish is described below, however they don't describe how to use the data update cursor to update the attribute column. data - Group values based on range of ...
0
votes
2answers
74 views

PostgreSQL/PostGIS - group by series of values

I need to sum up linear objects' length and to group them by intervals of several years. I have one table storing my objects like this : - gid serial NOT NULL, - year INTEGER, - the_geom ...
0
votes
0answers
90 views

Sort Proximity Results Into Groups Based on Distance from Center

The scenario is as follows: I have a database of pizza places with review averages. I want users to be able to find pizza places near a location and have them sorted by distance. Pretty straight ...
1
vote
1answer
186 views

How to do point-to-point near analysis conditional on common attributes of the two layers in Arcgis 10.2 (advanced)

I am measuring the closest straight distance from cities of interest (in a layer) to their capital cities (in another layer). Basically, distance between a city and a capital city is calculated if ...
3
votes
1answer
383 views

How to add an ID based on attributes in ArcMap 10.1

Given are: a polygon shapefile/feature class (FC) containing municipal districts a point shapefile/FC containing locations of, lets say, trees. My goal is to append an unique value (1, 2, 3, ...) ...
2
votes
4answers
159 views

Best way to 'join' polygons

I'm looking for the best ways to 'group' a budge of block polygons in a new polygon that should be the town. My block layer is something like this: Or zoomed: And I'm looking to get something ...
1
vote
1answer
126 views

Wrong output wth group by and aggregate function in spatialite

I have a grid and for every cell I want to set the column "landuse" according to the largest intersecting polygon. SELECT grid.PKUID, landuse.landuse, ...
15
votes
5answers
292 views

How to start a local GIS Users Group

My immediate geographic area is lacking an organized local GIS Users Group. I belong to a group that meets a couple times a year, but its about 1.5 hour drive. I'm thinking about starting up a Users ...
3
votes
4answers
4k views

How to group and count attribute data?

I have a problem with group same data to count it. For example, i want to group same code to one and count them. I can do it when i use MapInfo (Pic 1) but i can't in QGIS. (Pic 2: i can classify ...
2
votes
2answers
1k views

GROUP BY clause in the UpdateCursor arcpy.da

I need to specify a "group by" clause for UpdateCursor arcpy.da. From here I found out that it's possible to do using an optional pair of SQL prefix and postfix. But there are no examples and I'm ...
0
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0answers
196 views

How to draw polygons around known clusters

I need to split up an area into non-overlapping, but contiguous territories. I have n points on a map, which are partitioned into k sets. The partition is only partially geographic, meaning that ...
4
votes
2answers
8k views

group by timestamp interval 10 minutes postgresql

I need some help on this: I need to group by a period of time spliting up by 10 minutes: I have this query below that returns me a result set SELECT timestamp FROM table_1, ...
2
votes
1answer
350 views

Field calculation in ArcGIS Desktop?

i have a data which contain a code of area an value of area in shapefile, ex.: area|value 1|33 1|43 1|31 2|12 2|43 3|66 3|76 the question is how to calculate total value per area with arcgis, i ...
7
votes
0answers
684 views

Grouping analysis of points to divide polygon into n number of sub-regions using QGIS?

I'm attempting to create n sub-regions from a polygon based on a cluster analysis of a bunch of overlapping raster layers (physical layers, eg: depth, currents, waves). Briefly, I can create a ...
5
votes
2answers
389 views

Grouping lines together to form one line after a distance threshold is met: ArcGIS 10

I have lines on a map showing the most direct way from point data to the coastline (polygon). I would like to group the lines if they are close to each other by a distance that I can set. Where the ...