Questions tagged [dissolve]

To merge features based on specified attributes.

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3
votes
1answer
283 views

How to dissolve by two fields using C#

I need to dissolve a feature class based on two fields for the dissolve_field parameter and two fields for the statistics_fields parameter. Does anyone have an example of how to do this using C#? ...
6
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1answer
2k views

Trouble when Dissolving Geopandas Polygons

I have dissolved polygons with geopandas. However, the head of attribute table became values of this table. How can I fix this trouble? See:
3
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0answers
45 views

Dissolving closest area or area with biggest shared boarder [closed]

I am almost finished with a very large districting project but I'm having problems with this last step. I am using ArcMap I have made districts that needs to be larger than 150 residents. My last ...
0
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1answer
79 views

Delineating boundary around many small polygons to reduce number of polygons but retain relative coverage using ArcGIS Desktop?

I am using ArcGIS Desktop 10.3 with an Advanced license. I ran the slope tool on a DEM and converted the resulting raster into a shapefile with two polygons, one with slopes > 40% grade and the ...
1
vote
1answer
70 views

Sum of features from one layer to another

I have two different shapefiles and I work in Arcmap. This is what I have: The areas in picture 1 are smaller areas and the areas in picture 2 are in an aggregated form. File 1 contains number of ...
0
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1answer
126 views

ArcMap Dissolve tool only dissolving a few entries

So I have a shapefile which is divided into 7 habitat categories, with 1845 polygons, and I am trying to dissolve it so I only have 1 line showing each habitat with the total area. After dissolving, ...
2
votes
1answer
278 views

Dissolve large shapefile in ranges

I have a polyline with more than 15 mio attributes. all have more or less unik numbers in the field I would like to dissolve over. I would like to dissolve this field so there are e.g. 5 categories ...
4
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2answers
550 views

ST_Union creates holes in polygon

I downloaded a shapefile where admin(country) and province of the world are located (http://www.naturalearthdata.com/downloads/10m-cultural-vectors/10m-admin-1-states-provinces/). For each country, ...
7
votes
1answer
1k views

Cleaning large Shapefile using v.clean in order to dissolve features?

I'm having real problems cleaning up and reducing the size of a Shapefile which is published by the UK's Environment Agency. It shows the extents of the LiDAR open data they publish: each polygon is ...
2
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1answer
115 views

How can I remove easily vector leftovers within dissolved polygons?

I got an official government shapefile with zip code areas. After I dissolved the zip codes to the desired aggregated polygons, there are partial vector leftovers within the polygons. How can I clean ...
1
vote
1answer
113 views

Buffer Polygons change shape after running Dissolve Tool [closed]

I am trying to dissolve my buffer polygons but when I do so the shape changes while dissolving. See pictures below. I am starting with point features, then I buffer them afterwards I want to dissolve ...
1
vote
1answer
72 views

Dissolve connected lines until line forks

I have a lot of small lines which i need to connect, but only if connection point has 2 connected lines. When there is a fork with 3 or more connected lines, i need them to stay separated. Is there a ...
2
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0answers
299 views

QGIS Dissolve running out of memory

I have data about the basic municipality areas of Mexico in a shapefile. I also have data about which metro areas they correspond to (csv). I would like to dissolve them -or so I understand from ...
1
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0answers
88 views

Dissolving polygon features with duplicate set of attributes [closed]

I have one shapefile with thousands of polygon features. Many of them have the exact sets of attributes. So I want to make those features into one so that I can reduce the number of features from a ...
2
votes
1answer
228 views

Dissolve polygons based on max attribute value and retain attributes for that feature?

I want to dissolve a layer containing 9 features and have remaining in the attribute table only the attributes associated with max area feature. I have tried several dissolve tools within QGIS but ...
4
votes
2answers
1k views

ArcGIS dissolve not dissolving records

I have large NJ state wide parcels layer that I dissolved down to 6 records. I now want to dissolve it down too 1 record. 6 record dissolve my input into dissolve tool result of dissolve Why is ...
1
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0answers
88 views

SQL trigger that dissolves feature class based on multilabel fields

I am about write an SQL trigger which dissolves a feature class based on 5 fields, I used to do this using dissolve tool in the Arcmap as the following screenshots: Now, I need this process to be ...
0
votes
1answer
92 views

Dissolve adjacent polygons into collections of larger polygons, rather than a single überpolygon

I have a county's worth of census tracts, and I need to combine adjacent tracts into larger polygons. Here's an example of what I'm looking for: This is four smaller tracts combined into a single ...
4
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2answers
818 views

Dissolving by two fields in QGIS?

Is there a way in QGIS to dissolve a vector by two or more fields?
1
vote
1answer
476 views

Using QGIS batch-processing dissolve?

How to use QGIS batch-processing dissolve: Using QGIS 2.16 under Win 10 (see screenshot). Questions: Why must I have at least two rows. When I open the window I have 3 rows. Using the red minus-icon,...
1
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1answer
243 views

Error message with dissolve in QGIS

After about 10 hours of dissolving, QGIS gives me this message :-( Any ideas, what this means and maybe how to correct?
1
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1answer
170 views

Merging overlapping polygons with Dissolve?

I created a service area of multiple facilities and as a result I got a feature class with multiple overlapping polygons of the same value. To merge all these polygons I tried to use Dissolve tool ...
2
votes
1answer
118 views

Merge polygons based on five first digits in id

I have a shapefile with 1364 polygons in the Stockholm area: But the "areas" are too detailed - I want to make fewer and bigger polygons. I would like to merge/dissolve all "BASKOD2010" id's based on ...
2
votes
2answers
279 views

Dissolve polygons by specific field- but only neighbors polygons

I have a polygon layer and I want to dissolve the polygons according with a specific field. But I want sth extra. I would like to dissolve only the neighbors polygons. For example, look the below ...
0
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2answers
707 views

QGIS 2.16.3 crashes when trying to dissolve any shapefile

When I try and use the dissolve tool (vector>geoprocessing tools>dissolve) QGIS 2.16.3 crashes and produces a minidump file. This is with any shapefile that I use. I have also tried it on a friends 2....
1
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0answers
90 views

Saving vector layer with joins converts joined attributes from double to integer in QGIS?

I'm using QGIS 2.16.3. I'm trying to use the "Dissolve with Stats" plugin, which requires me to save the layer with the joined attributes. However, saving the layer converts the joined fields from ...
0
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1answer
193 views

Weighted-area averages using dissolve for SINGLE PART features

I'm trying to compute area-weighted averages of a field when dissolving a feature layer. I thought the solution would be to: create a new field that is the product of the original field value and the ...
2
votes
2answers
160 views

Dissolving creates fragments in the middle [duplicate]

When dissolving a polygon shapefile I get fragments in the middle (see pictures) in Qgis and R using the functions from rgeos. Has anybody an idea where this comes from and what can be done to deal ...
2
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0answers
583 views

Dissolve taking a really long time ArcGIS 10 [closed]

I'm having an issue running several dissolves in both Arcgis 10.1 and Python 2.7.2, and 10.2.2 and Python 2.7.5 using arcpy.Dissolve_management (I'm working on 2 virtual machines). In both cases the ...
1
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1answer
2k views

PostGIS dissolve geometries from shapefiles

I have a municipal polygon shapefile of 380 municipal records with receptor(schools, hospitals etc..) sums for each municipality. I am trying to use Postgres/PostGIS to dissolve this municipal polygon ...
2
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1answer
792 views

Dissolving Points using QGIS Processing?

Is it currently possible to create multipart features of points data based on one or more fields?
0
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1answer
194 views

Adding clip function to python buffer script

I have posted my script for buffering and dissolving polygons. Could someone help me incorporate an Erase function in order to erase the input file from the buffer? Script: import arcpy infc = r'...
1
vote
1answer
52 views

Dissolve polygons for each column in ArcGIS

I am wondering if there is a way to repeat the dissolve process for each column in order to have just one shapefile as outcome. In the image an example of input data and desired outcome.
1
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2answers
65 views

Clipping but using outer border of grouped polygons only

I am buffering, dissolving, and then clipping a 100 mile radius around each POI over a US map. I got the map from the US Census, and it represents every Zip Code Tabulation Area. Unfortunately, there ...
2
votes
3answers
914 views

Buffer and union of large shapefile?

I want to create a buffer of 5km around the coastline, and save that as a separate shapefile. I have a shapefile with almost 180,000 features. It's a line shapefile, representing the coastlines of ...
5
votes
1answer
1k views

Dissolve only overlapping polygons in R

I have a spatialpolygons-dataframe in R that contains overlapping polygon features. I would like to dissolve only the overlapping features into separate polygon features (one feature per par of ...
2
votes
1answer
98 views

QGIS dissolve is changing the shape of polygons rather than just combining them

QGIS novice here. I have a shapefile for US census PUMA (public use microdata areas). One of the attributes in my shapefile is the metropolitan area of the PUMA. I want to combine PUMA's which are ...
2
votes
1answer
1k views

Dissolve using ogr2ogr gives 'no such function: ST_union'

I am trying to dissolve a shapefile using ogr2ogr but I am getting error no such function: ST_union: Command: C:\ms4w>ogr2ogr "C:\output\test-dissolved.sh p" "C:\input\test.shp" -dialect ...
7
votes
1answer
637 views

Dissolving shapefile but retaining a list of original attribute value in QGIS

How can I dissolve a polygon layer in QGIS based on a single attribute but keep all (or some) other attributes at the same time? This is how I want to retain fields: There are at least two fields I ...
1
vote
1answer
82 views

Dissolve doesn't work with empty layers

I have this model: The tool dissolve has this precondition of the Calculate Tool in order not to run with empty layers: However, when it runs with a empty layer it returns the following error: ...
2
votes
0answers
192 views

Dissolve and join features based on an attribute range [closed]

I have a CSV file of Postal Codes containing average energy usage information. Furthermore, I have Feature Classes (both points and polygons) of Postal Code areas in a File Geodatabase. I wish to join ...
1
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0answers
108 views

How to convert building outlines to Polygons?

I have line vector layer which contains contours of buildings in the form of separate segments. I want to convert lines to polygons (QGiS 2.17) but it doesn't work. I'm trying to solve this problem ...
1
vote
1answer
385 views

Why doesn't Dissolve with stats plugin work in QGIS 2.14?

In ArgGIS 9.3 there is a function of ArcToolBox named Summary Statistics (Analysis). I'm finding a similar function on QGis. One of these is Dissolve with stats (plug in) but on my version of QGIS (...
1
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3answers
212 views

QGIS Dissolve: Limit output file format to .shp only

I'm new to QGIS and recently I've been trying to dissolve two large shapefiles together after they have been merged. It's taking an awful lot of time for each operation and I'm trying to speed up the ...
2
votes
0answers
345 views

PostGis - st_union polygons, keep sum of attribute

There are multiple My current query is: SELECT (ST_Dump( ST_Union( way ) )).geom AS way, 10000 AS way_pixels FROM ( SELECT way, way_pixels, ...
1
vote
1answer
352 views

How to dissolve by two fields?

I have a shapefile with many polygons in it. I want to dissolve by two fields. Is there any possible way to dissolve this by NAMA_KPH and PL15_ID?
1
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0answers
240 views

ArcGIS Dissolve failing with small polygons [duplicate]

I have an arcpy script which clips (Clip_analysis) a shapefile of polygons to a grid square, converts any multipart polygons created to singlepart polygons (MultipartToSinglepart_management), runs ...
3
votes
1answer
509 views

Converting Road Lines to a Binary Raster Image

I got road data from the USGS database and imported it into QGIS. And I want to transform it into a binary raster image that looks like this in QGIS (this is only a processed screen shot but I want ...
1
vote
3answers
270 views

ArcGIS Dissolve/SQL group by

I have a GIS layer that has thousands of Facility IDs. For each Facility ID there can be multiple Chemical ID's. For each chemical ID there is a maximum of 3 zone types. Zone A, B, C. But there is not ...
1
vote
1answer
124 views

ArcGIS 10.3 Dissolve tool splitting up lines, not dissolving them

I have noticed strange behaviour with the Dissolve tool so tried a test on three line segments, snapped to the same central point. The line segments each consist of exactly two vertices i.e. the end ...