To merge features based on specified attributes.

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1answer
267 views

Query to Dissolve Nearby Polygons on Hive

I am using the ESRI spatial framework for Hadoop, that extends Hive to use spatial types and operations. My objective is to translate a set of simple queries on PostGIS into Hadoop, in order to ...
3
votes
1answer
136 views

How to select polygon close to each other?

I have grass patches and I put a buffer of 250m around them. I did a "dissolve to get larger polygons that overlap, but the attribute table emitted a lot of information, which are important such as ...
3
votes
2answers
705 views

In PostGIS, how do I merge a multilinestring into a single linestring, keeping the pieces in proper order?

I have a multilinestring made up of several pieces, some of which are facing the wrong direction. (Accessible here: http://pastebin.com/89Zcixv5 ) I think what I'm looking for is some utilization of ...
3
votes
1answer
237 views

How to achieve better Dissolve results?

I applied the Vector>Geoverarbeitungswerkzeuge>Auflösen (Dissolve) on a zoning plan (see picture zoning plan). I used the attribute village name as the dissolving criteria. The resulting geometry for ...
3
votes
0answers
85 views

Dissolving polygons in a large dataset

I need to dissolve polygons by the ID attribute in a large dataset (+-1gb shapefile). I have been struggling to find an efficient method to do this. I have tried the following methods: Postgis ...
3
votes
2answers
181 views

problem merging polygons based on a column value - using Spatialite

edit: as I am unfamiliar with any tools I decided to try my luck with PostGis. I imported my data. and executed the query : create merged as select delomrade_code, st_union(geometry) from grunnkrets ...
2
votes
1answer
1k views

How to measure the area of polygons within a fishnet

I am currently trying to measure the area of polygons within each square of a fishnet. The aim of what I am doing is to work out the proportion of different agri-environment schemes by 1km squares. ...
2
votes
2answers
707 views

Why is my dissolve not outputting my features correctly?

I have a parcel polygon layer consisting of ~30,000 polygons that can have one of three values for city limits: 0, 1, and null. I execute a dissolve on this layer with "Create Multipart Features" ...
2
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2answers
137 views

Dissolve line segments in QGIS if they touch and fall within the same class. (tools or script?)

I have line segments that have the following 3 attributes (Class, start_point, end_point). I would like to merge/dissolve line segments that fall within the same class if they intersect (touch). i.e. ...
2
votes
2answers
143 views

Dissolve tool misses out two polygons

I'm trying to dissolve polygons based on a code number in the attribute table. It all works well, with an exception of two polygons that fail to dissolve - they literally drop out from the output. It ...
2
votes
2answers
3k views

Problem with merging and dissolving a shapefile in R

I am migrating from ArcMAP to opensource GIS. I've succesfully installed R and many packages in a Ubuntu 12.04 machine. I am used to linux and programming in C, but not to R and its syntax. I am ...
2
votes
1answer
81 views

How to dissolve geodatabase map across two subdivision levels in Arcgis 10.2

The existing polygon database contains attribute table with the following structure, and has three levels; country, state, and city (and many other countries not listed below). I want to dissolve the ...
2
votes
1answer
1k views

Dissolve features in ArcGIS using multiple attributes

This may sound simple, apologies if I missed some earlier discussion on same subject. I have a big set of road data with road numbers and also zone numbers . The road names can repeat across the ...
2
votes
1answer
54 views

Dissolving a TIN using python/ogr binding

I have a TIN model where I remove some of the triangles (see fig. 1). Most of the triangles touch on one edge, some on one vertice. I would now like to generate a polygon shapefile containing the ...
2
votes
1answer
282 views

What is FME equivalent to ArcGIS Dissolve?

I am trying to dissolve polygons that are spread out across a region. ArcMap's ModelBuilder will dissolve these polygons into a single, multi-part feature. How can I get FME to do this same thing? I ...
2
votes
1answer
59 views

Dissolve tool is splitting features rather than dissolving them

I had UK area divided into six different zones. I wanted to dissolve my feature class by zone just so I have six features in it. I used Dissolve tool which worked fine for five zones. One of the ...
2
votes
1answer
404 views

dissolve polygons of GeoJSON with gdal/ogr

I have a GeoJSON with only polygons in it. I have to dissolve (merge) the polygons with the same "DN"-value. I found out that you can do it with shapefiles like this: ogr2ogr outputfile.shp ...
2
votes
1answer
59 views

ArcGIS Dissolve leaving feature snippets in dissolved polyons. Repair doesn't fix

I'm trying to dissolve some low-level polygons, but the result I'm getting has lots of little pieces of lines left floating around in the output polygons. I've tried doing "repair geometry" on both ...
2
votes
2answers
287 views

arcpy.Dissolve fails; need a arcpy dissolve to multipart workaround

I have a arcpy script in which I am using arcpy.Dissolve on a single feature class with multiple features to get a single multi-part feature in the output. The script is successful only part of the ...
2
votes
1answer
168 views

Merge section polygons in PLSS

I am trying to merge quarter quarter sections of polygons from PLSS into a quarter section. However, I also want it assigned to correct Township/Range/Section while merging. I know I can hand merge ...
2
votes
1answer
3k views

Dissolving two different buffers together so not overlapping using ArcGIS Desktop?

I am trying to find out how many registered sex offenders live within 2,000 feet of a school/park in a specific county. The park buffer and school buffer are dissolved but not together. I am also ...
2
votes
1answer
44 views

Dissolving Features from different Layers

I'm trying to dissolve polygon features from different layers by their FID. If two polygons have the same FID the result should be one single polygon. Maybe this drawing will help to make clear what ...
2
votes
2answers
100 views

Concatenate fields on a Dissolve

I have a feature class that that I would like to dissolve. Upon the dissolve, I would like to concatenate a comment field, which is a text field. How can I do this? Conceptual idea below:
2
votes
2answers
119 views

Merging lines (that might cross) at common endpoints without multi-part features in the result

I have a polyline dataset I'm trying to merge / dissolve segments based on an attribute into continuous single lines. The problem is that some of those segments cross each other but need to be ...
2
votes
1answer
536 views

QGIS 2.4 dissolve doesnt work properly, why?

I am used to work with ArcGIS and now I started to explore QGIS more. I have problem with dissolve function. I have administrative borders and I would like to dissolve them into higher administrative ...
2
votes
2answers
331 views

Aggregate/dissolve MySQL geometry

On Centos, I have a MySQL 5 database with a MyISAM table that has a geometry column with a spatial index, containing US county boundaries. Trying to combine/aggregate/dissolve some of these into as ...
2
votes
1answer
665 views

How to define polygons overlapping each other?

I have a shapefile of landuse in different catchments. I want to calculate the percentage of each landuse category in each catchment using Tabulate Intersection. Before using this tool, I had ...
2
votes
1answer
209 views

Dissolving stream orders using Python rather than VB script?

I've been trying to dissolve streams, using orders programatically and I came across this VB script. The reason is that if I use ArcGIS dissolve, it merges the confluence of the same orders. I would ...
2
votes
1answer
607 views

Why does Merge then Dissolve return ERROR 000732: Input Features: Dataset … does not exist or is not supported?

I'm not sure why I'm running into this problem. I thought it might have something to do with the merged file being locked or open, but I don't see a "LOCK" file being created in Windows Explorer. ...
2
votes
1answer
1k views

How to correctly merge layers with overlapping polygons in QGIS/GRASS?

I have 4 vector shapefile that I would like to join/merge, without worrying about attributes. Here are the shapefiles. I would like to do an union and a spatial dissolve, but everytime I do a dissolve ...
2
votes
1answer
74 views

Dissolving features to only have multiparts when they are within 100 feet of one another

I want to have a selection of parcels that is dissolved by land owner and within 3 miles of a polyline. If the same owner owns parcels on opposite sides of a road (within 100 feet or so), I want the ...
2
votes
1answer
89 views

QGIS crashing/failing when dissolving multiple shapefiles in a Python loop

I am using QGIS 2.10 (but I've also tried 2.8) to loop through all the shapefiles in a folder (those ending in .shp) and perform a dissolve function on each of them. However, when I run the following ...
2
votes
2answers
254 views

Stratified Random Sampling with large dataset in ArcGIS?

I want to create a Stratified Random Sample with a land cover classification map. The purpose for the Stratrified Random Sample is to produce an Accuracy Assessment. I am using ArcGIS 10.2 with access ...
2
votes
1answer
69 views

Obtaining block structure from parcel data using QGIS or ArcGIS for Desktop?

I am trying to analyze the urban form of a city. I don't have the polygon file for streets, so I must derive block structure from parcel data (see image below). What tool could I use to accomplish ...
2
votes
1answer
1k views

Merging polylines together keeping the attributes of the largest one

I have a set of polygons with polylines running through them. I am trying to assign the polylines the polygon ID that they pass through the most. I have already split the polylines to the polygon ...
2
votes
0answers
27 views

Combining adjacent shapefiles and merging neighbor polygons currently divided by quad boundaries

The project I'm working on has been mapping ecological sites in ArcGIS on a quad-by-quad basis for the past 10 years. When entered into GIS, each quad has its own shapefile and the sites are cut off ...
2
votes
1answer
43 views

Dissolve singlepart features into multipart based on another polygon?

I'm working on generating a water feature layer that eliminates a lot of the swamp/marsh areas in my county. Using raster analysis (iso unsupervised cluster, majority filter, boundary clean, etc) and ...
2
votes
0answers
68 views

How to union linestring data distributed on multiple layers?

I have four shapefiles. Each contains a linestring as shown in the image. Each shapefile is represented as its own layer in QGIS. I would like to union these linestrings into one polygon which ...
2
votes
1answer
42 views

Spatial join by categories in QGIS

I am using QGIS 2.4.0 and I have a vector layer which contains a remoteness indicator which is broken up into 5 categories. I would like to turn this into a layer that has these 5 categories collapsed ...
2
votes
0answers
31 views

ArcGIS dissolve analysis output issues in geoserver wfs/ PostGIS

I have an ArcGIS dissolve analysis output (parcel data) that needs to be loaded on PostGIS and published as a wfs from geoserver. The issue is that the ArcGIS dissolve output shapefile, although can ...
2
votes
0answers
61 views

how to make a list of features constructing the dissolved feature?

I need to simplify my road network using the dissolve function to remove nodes not occurring on the intersections. the following code is doing that. arcpy.Dissolve_management(self.address_cor_layer2, ...
2
votes
0answers
99 views

Dissolve Statistics Fields and Statistic Type as Parameters in GeoProcessor

I have a published service which uses a dissolve. In arcMap the I get prompted for all the fields, including statistics fields and stat type. I have the statistics fields marked as parameters. ...
2
votes
3answers
826 views

Is there a dissolve / ST_Union function that will close gaps between features?

I've been reading a number of related threads about ST_Union, ST_SnapToGrid and ST_Dump but I haven't been able to solve my problem. The problem is I am trying to merge Tiger/line census tracts that ...
2
votes
1answer
438 views

Problem when executing Dissolve method in ArcEngine

I'm always having a problem in GP.execute() when trying to execute this method. Here is my code: Friend Function DissolveFeatures(ByVal pInFLayer As ESRI.ArcGIS.Carto.IFeatureLayer, ByVal ...
1
vote
3answers
636 views

Why would Dissolve stop working in ArcGIS for Desktop?

I have an ArcMap Add-In that completes various geoprocessing steps, including Dissolve (using ESRI.ArcGIS.DataManagementTools.Dissolve). This tool worked at 10.0, but I just upgraded to 10.1 SP1 and ...
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vote
2answers
104 views

Topological errors after dissolve - how to avoid/get rid of?

After dissolving a layer in QGIS 2.8, I get a lot of topological errors in the new (dissolved) layer. Any suggestions as to how to get rid of these errors without manually editing each one? ...
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vote
3answers
148 views

Why dissolve creates many extra features?

I have a shp file in Arcmap 10 that has ~16600 polygons. Some overlap. I want any polygons that are overlapping to be dissolved into single polygons. I want non-overlapping polygons to remain the ...
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2answers
785 views

Looking for dissolve algorithm for Javascript

I have three adjacent polygons that together make up a larger shape. I need an algorithm that will dissolve the internal borders leaving only the outside border. An example would be a group of ...
1
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2answers
475 views

Merge Error: Not Enough Memory

I'm attempting to make a flood plain map for a school project, and am using FEMA Flood Hazard Symbology for the legend. I've dissolved by a Flood Zone Field, but am left with two attributes both named ...
1
vote
3answers
8k views

How to combine rows in attribute table using ArcGIS for Desktop?

I have an attribute table with three columns "FID" "Shape" and "Class" All records have the same shape (polygon). Each record has its own FID. I have three classes, "A", "B", or "C". I have twenty ...