To merge features based on specified attributes.

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4
votes
5answers
323 views

Dissolving polygons fails on computers with small amount of RAM

When I'm trying to dissolve a polygon through an arcpy script the operation fails with the 999999 error on computers with small amount of RAM [~3 GB] (known issue). Unfortunately neither this, that ...
0
votes
1answer
130 views

Dissolve multiple rows straight into one layer and add OIDs into table

I am currently running this script to direct multiple dissolves of a polygon layer FC = "BLPUsCavPlace" TABLE = "BLPUsCavPlaceContigBLPUs" FIELDS = ["blpuid", "contigid"] with ...
1
vote
1answer
88 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 ...
1
vote
0answers
15 views

Polygon dissolve in DB

I have a polygon feature class with more than 100,000 polygons in DB2 table. I would like to dissolve them based on a single field to reduce the row numbers. Is there any commands / SQL in DB2 to ...
1
vote
1answer
132 views

Dissolve large dataset in ArcGIS and QGIS

I have more than 80k point data. I have created few buffer from 1 to 5 km of them. Now I want to get the covered area by 1 km to 5 km buffered range. For this I have tried to dissolve those individual ...
3
votes
1answer
286 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 ...
2
votes
1answer
24 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 ...
1
vote
1answer
164 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
0answers
39 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, ...
1
vote
2answers
113 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 ...
6
votes
3answers
2k views

Dissolve or unsplit lines on common attributes in PostGIS or GRASS?

I have a road centerline shapefile that has roads split at every intersection. However, I would like to join LINESTRINGs that have a common set of attributes into a single LINESTRING. So long as the ...
0
votes
1answer
70 views

How to dissolve naturalearth vectordata with gdal?

trying to use the workflow described by @aflaciano at How to render area that crosses 180°? I did the following: 1) downloaded and installed gdal-111-1600-x64-core.msi from ...
10
votes
1answer
5k views

Merging adjacent polygons in shapefile that has been split at tile boundaries?

I'm currently using building data from the Ordnance Survey Vectormap District and I've noticed that a lot of building polygons are split in 2 because of the way the OS split up the shapefile. This is ...
1
vote
1answer
55 views

How to dissolve adjacent parcels by same owner but include those parcels located across the street with the same owner?

In trying to determine the total contiguous stream length per landowner, I dissolved parcels by parcel owner name attribute and intersected these dissolved parcels with streams. However, dissolving ...
4
votes
1answer
689 views

What dissolve tool in QGIS allows me to summarize statistics for multiple attributes?

Is there a tool or plugin in QGIS that resembles ArcGIS 10's Dissolve tool? I'm trying to dissolve several polygons (parks) around the boundaries of another layer of polygons (cities), while ...
0
votes
1answer
109 views

Why does the “Dissolve” tool in QGIS create an empty layer?

I have a shapefile containing cadastral data. I would like to dissolve the polygons using my field "OwnerName". My goal is to get one polygon per landlord's name. When I use the "Dissolve" tool, QGIS ...
0
votes
0answers
56 views

Need advice on converting large geodatabase into shapefile or postgis

tl;dr: I have a fgdb w/ 800k tiny polygons representing high risk flood areas. I need to sum the area of these polygons within each administrative boundary (HUCs) and have a ratio per huc of high risk ...
1
vote
3answers
133 views

Why does dissolve stop working at 10.1?

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 ...
2
votes
2answers
260 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 ...
0
votes
1answer
53 views

QgsGeometryAnalyzer.dissolve problems

I am completely new to the QGIS python api and I am running into an error which I cannot solve when trying to use the dissolve class. I used the basics of the PyQGIS Cookbook. In my understanding ...
1
vote
2answers
59 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 ...
5
votes
2answers
10k views

How to combine adjacent polygons sharing similar trait into single polygon?

I have a large dataset of habitat classes which I have further simplified down into my own unique classes. However, it resulted in there being habitats adjacent to each other with the same forest ...
5
votes
4answers
2k views

How to improve upon ArcGIS Buffer/Dissolve performance?

I'm wondering if anyone else has experienced significant performance penalties when using the ArcGIS buffer function with the 'dissolve' option on point features. My dataset is a shapefile of 260 ...
3
votes
1answer
269 views

How can i merge lines with same name and intersect each other?

I have shp file with 50k lines (roads). Many roads have same name like 'high road' . some of them are the same road (they intersect each other) and some are located in different places of the city. I ...
3
votes
2answers
2k views

Why is the Dissolve Tool not working?

I'm still having trouble with the dissolve tool and I've tried all of the solutions offered here including moving the process from the background and repairing the geography. I've also tried amending ...
2
votes
1answer
38 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
2answers
83 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 ...
1
vote
0answers
42 views

How to calculate Median of a table field in the Dissolve Tool of ArcGIS?

The Dissolve Tool of ArcGIS 10.0 has some statistical parameters as a type of calculation new values of each field in a process of dissolving of identical parameters . It has SUM, MAX, MIN, RANGE, ...
0
votes
1answer
47 views

Splitting hexagonal grid into segments, dissolve by location

I am a little bit frustrated because I want to do something I did 5 years ago and I can't figure out how to do it again. I am creating a turnover map of species communities using R and ArcGIS 9.3. As ...
1
vote
2answers
181 views

How to combine rows in an attribute table

I'm fairly new to GIS and could use some help with an issue I've run across. I have an attribute table with three columns "FID" "Shape" and "Class" All records have the same shape (polygon). Each ...
0
votes
2answers
99 views

Low resolution raster conversions to vector yielding millions of single pixel polygons. Trying to merge all directly adjacent polygons

I'm trying to scan plain pdf maps containing color-coded geographic regions and convert them into undifferentiated (I don't actually need them to contain any attribute data) overlays. My workflow is ...
0
votes
0answers
42 views

How to get the boundaries of a polygon by property

I have the cartography of my city (Santiago) and i need to obtain the nodes that conform the hull (not necessarily convex) of different districts, the boundaries. Each node has the same "DIS"( ...
1
vote
1answer
58 views

MSSQL server 2008 dissolve sql query

I have a set of spatial objects in a MSSQL server 2008 R2 trying to dissolve adjoining objects where one of the attributes are equal. The table below is somewhat representative to my original table: ...
1
vote
1answer
104 views

python dissolve by field error

I would like to dissolve a feature class by a field. When I run the code, I receive an error that says, "invalid topology [out of memory]" I have 16GB of RAM and terabytes available on the hard drive. ...
0
votes
0answers
60 views

Dissolve a Geometric Network in ArcGIS

I have a geometric network of water mains in ArcGIS. It it composed of a line feature class. I would like to dissolve it based on whether line segments share common endpoints only. So basically ...
6
votes
3answers
15k views

How to dissolve overlapping polygons?

I have a query regarding the dissolving of polygon features in ArcGIS 9.3. I only have the bare-bones license and an extremely basic knowledge of VB. I have a large shapefile with around 4500 ...
1
vote
3answers
347 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
2answers
138 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" ...
1
vote
0answers
25 views

How do I dissolve to a predetermined number of contiguous geographies based on equal division of a value?

Let's say I have a layer that is the state of Oklahoma, broken up by county, and I want to dissolve it into contiguous regions of roughly equal population size, and I want to define how many regions ...
2
votes
1answer
146 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 ...
0
votes
1answer
324 views

Dissolving shapefile python script not working, syntax help please

I do not understand why this simple script won't work. I can get it to dissolve in model builder but not from a script that I run from inside the map document. My output results are 4 polygons, just ...
2
votes
1answer
296 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 ...
0
votes
1answer
60 views

Dissolving polygons closers than 50m into a single shape QGIS

I’m new with GIS (coming from a CAD background) and using QGIS 2.0.1. I have a very detailed map of urban fabric in a UK region, to the detail of individual buildings. I want to simplify that map by ...
14
votes
4answers
4k views

What is the best way to join lots of small polygons to form a larger polygon?

I have the following layer using SRID 27700 in postgis: It's every administrative region in the UK, and (as you can see from the colour grouping) each of them has a text field specifying the county ...
1
vote
2answers
2k views

How to Merge/Dissolve Polygons By Common Attribute Field in QGIS?

I have joined corresponding Local Enterprise Partnerships table data into a polygon shape file containing UK Local Authorities. How do I Dissolve or Merge the the Local Authorities polygons by ...
5
votes
2answers
109 views

Select 90% matching attributes

I have a shapefile (.shp) of 180k roads with information of street name. I need to do a Dissolve on that road network to make only one feature per name. But I have a problem by doing that task ...
2
votes
0answers
48 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
1answer
222 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 ...
0
votes
0answers
48 views

Dissolving overlapping polygons - issue in QGIS [duplicate]

I have the OS Code-Point map which I want to dissolve into the regions that my company use. I have used the dissolve function in QGIS, but it is having a problem where a vertical street overlaps with ...
0
votes
2answers
158 views

How can I get a single part dissolve using ST_Union or ST_Aggr_Union?

I am trying to get dissolve functionality using ST_Union using this query : SELECT c.fid, ST_Union(c.boundaryshape) FROM c GROUP BY c.fid; Than I found instead of using ST_Union I should use ...