To merge features based on specified attributes.

learn more… | top users | synonyms

2
votes
2answers
927 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
2answers
119 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
252 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
182 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
474 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
621 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
1answer
976 views

PostGIS Dissolve/Union close polygons

I have approximately 1 million polygons that have been split by lines. However, this has caused one half of a polygon to be separated by approximately 50cm from its other half. After doing a lot of ...
2
votes
1answer
818 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
26 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
22 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
46 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
64 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
294 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
244 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 ...
1
vote
3answers
92 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 ...
1
vote
2answers
229 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
vote
2answers
139 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
2answers
61 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 ...
1
vote
1answer
65 views

Postgres/PostGIS: Dissolve multiple fields with COUNT (Point shape)

I have loaded point .shp feature classes into Postgres 9.3 db, and enabled postgis,plpgsql,postgis_topology extensions. I'm looking to dissolve multiple fields within a single table 'TABLE1' and add ...
1
vote
2answers
1k 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 ...
1
vote
1answer
165 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. ...
1
vote
1answer
99 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
74 views

How do I create multiple polylines from single polyline that consists of disjunct sections?

My goal was to create a network of polylines in NHD plus based on start and end points associated with sampling locations. Dissolving by stream name was my first step and has worked just fine for ...
1
vote
1answer
25 views

Unsplitting Zpolylines without flattening vertical line segments?

Trying to figure out how to fully keep vertical line segments when using Dissolve/unspit lines... The first image shows the original Zlines in Arcscene The second image is the result of a Dissolve ...
1
vote
0answers
33 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 ...
1
vote
0answers
80 views

Is table with 20,000 rows and 5 columns too large for Dissolve of ArcGIS for Desktop?

Is a table with 20 000 rows and 5 columns too large for arc map 10.2.1? I have tried several things without success to dissolve this table based on one feature. The table was obtained from the ...
1
vote
1answer
55 views

Merge polygon based on other line shape file PostGIS

I have a polygon shape file and a line shape file. I would like to merge two polygons which shares the same border along with line shape. Finally the line should be removed in polygon shape file. In ...
1
vote
0answers
25 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
78 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 ...
1
vote
0answers
78 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, ...
1
vote
1answer
141 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
26 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 ...
1
vote
3answers
501 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 ...
1
vote
0answers
53 views

Determining homogenous blocks of individual tree species in a woodland, and creating a new shapefile without blocks/polygons of < minimum area?

I'm working on a project attempting to identify suitable woodland habitat for red squirrel translocation wherein conservation efforts could be focused. Below is a small section of the map showing ...
1
vote
0answers
115 views

Why doesn't dissolve finish? It just stops without error message

I have a shapfile of the whole UK that contained Postcode area, district, and full postcode. I was going to try and dissolve the regions into seperate business areas by joining a lookup table that ...
1
vote
0answers
192 views

How can I merge postcode sector polygons into larger territories in QGIS?

I'm new to GIS so patience might be required :-) I'm building a basic web-based mapping tool for business use, to be used as a demo to show that we need one but managers don't know it yet! So far ...
0
votes
1answer
422 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 ...
0
votes
2answers
119 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
2answers
204 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 ...
0
votes
1answer
23 views

Dissolving and returning values from primary lines

Im building a model and I need to dissolve line, that I marked in picture, to a line with field(NUMBER_OF_LINES) value of 2. Thsi filed represents how many lines were constructed to one line after ...
0
votes
1answer
155 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 ...
0
votes
1answer
65 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 ...
0
votes
1answer
143 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
61 views

Statistics field in the dissolve tool not always accurate

When I run the Dissolve Tool using a Statistics Field (SUM being the statistic type) and proceed to check the SUM values for accuracy by comparing against the data in the original feature class, I ...
0
votes
0answers
103 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 ...
0
votes
1answer
142 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 ...
0
votes
1answer
222 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 ...
0
votes
1answer
73 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 ...
0
votes
0answers
50 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"( ...
0
votes
0answers
84 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 ...