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Questions tagged [comparison]

The act of comparing or the process of being compared.

9
votes
1answer
2k views

Comparison of three contour lines

I am looking for a way to spatially quantify the difference between three contour line shapefiles. More specifically, I have two elevation rasters which I intend to create contour lines from, but ...
9
votes
5answers
20k views

Comparison of Open Source Desktop GIS Packages

I'm curious as to what comparisons are out there between different Open Source Desktop GIS software packages. I'm aware that there has been a QGIS and gvSIG comparison on this site but I am looking ...
9
votes
2answers
575 views

Tools to compare unversioned copies of geospatial data [closed]

My office has about 100 GB of geospatial data of varying forms (imagery, feature classes in geodatabases, LIDAR, tables, etc) that have gone somewhat unmanaged for the decade during which they were ...
7
votes
2answers
229 views

How to check what changed inside the updated shapefile?

I am using different shapefiles from open data in Switzerland. They have just updated the whole set. My question is: how to compared two layers (new and old version)? I would like to know the ...
3
votes
2answers
854 views

How can a statistically significant difference between rasters be calculated?

so after some gruelling use of MaxEnt I have four occurrence probability rasters for the four quarters of the year, each one is about 70MB+. I want to test whether they are significantly different ...
6
votes
3answers
205 views

What is the PostGIS 2.x equivalent of the pre-PostGIS 1.5 ~= operator?

Stemming from my other question: When would a PostGIS geometry compare using ~= return true when ST_Equals returns false?, what is the PostGIS 2.x equivalent of the pre-PostGIS 1.5 ~= operator? It ...
5
votes
2answers
331 views

Different models, different contours: are they comparable?

I will get contour lines of electromagnetic field strength around power lines. The contours will be calculated by different agencies using different models. We need to check whether the resulting ...
6
votes
3answers
2k views

Comparing choropleth maps statistically

I have several sets of choropleth maps showing ranges of poverty by census tract, each using a different poverty measure. All of the maps use the same categorical ranges to define poverty status. The ...
3
votes
2answers
4k views

Python code to compare two fields in different feature layers?

I have two shapefiles which encompass 3897 features each. Corresponding shapefiles (village and watershed that flows into it) have the same ID (ws_id in one, OBJECTID in the other). Many watersheds ...
2
votes
1answer
3k views

How to compare string fields in the same table with ArcGIS 10

I don't know exactly if there is a tool for this or a maybe a python script could be more suitable. I want to compare string elements from a field (POI_NAME) with another string element in another ...
1
vote
1answer
149 views

How to compare polylines attribute from the same GRID cell in ArcGIS 10?

I need some help because I do not know how to model this issue: I have two polyline shapefiles. They have an attribute that I need to be compared. These are roads from different sources. So, I have ...
1
vote
3answers
22k views

Comparing differences in two polygon shapefiles using ArcGIS Desktop? [duplicate]

I am a new user to Arcmap 10. I've been trying to figure out how to compare two polygon shapefiles. I need to figure out what the difference is from 2007 - 2013 (increase/decrease) in a couple of ...
0
votes
4answers
747 views

Searching for changes of 2 layers based on geometry, Arcgis for desktop (ArcEditor

I´m trying to make a tool that would be able to compare 2 layers of any type (polygon, point, polyline) and find differences between them. Lets say i have a layer of roads (Polyline) from 2005 (layer ...
3
votes
1answer
675 views

When would a PostGIS geometry compare using ~= return true when ST_Equals returns false?

I have a couple of featureclasses in a 10.2 geodatabase/PostgreSQL 9.2.2 database and I've been struggling with the FeatureCompare tool--it is telling me geometries are different on some features ...