The act of comparing or the process of being compared.

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2
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0answers
56 views

Can 2 GIS layers which representing the same area be compared directly while having the same datum but different coordinate system?

My question is about how coordinate systems affect comparison of different layers - I have tried to refresh my memory about coordinate systems in GIS, but am still unsure about this situation. I am ...
9
votes
0answers
147 views

Identifying overlapping time intervals with two more criteria in R?

I have to check birds observations made over a longer period for duplicate/overlapping entries. Observers from different points (A,B,C) made observations and marked them on paper maps. Those lines ...
0
votes
2answers
53 views

Can I change the pimary key for feature class comparisons with ArcPy

I'm using ArcPy to compare two feature classes from Esri file geodatabases using the Feature Compare (Data Management) tool. The script itself works very well. However it always uses the OBJECTID to ...
4
votes
1answer
608 views

comparison of Historical aerial photographs to today's satellite images

I'm working on a project in which I have to compare vegetation cover changes. So we have 1950's aerial photographs which must be compared to actual satellite images. Images must be properly adapted ...
0
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0answers
37 views

comparing raster values over one specific transect

I have a raster with water temperature data. I used various kinds of filters over it (smoothing, sharpening filter etc.) in various combination. I want to compare the results, to check which ...
6
votes
3answers
151 views

Efficient processing of difference between input data and database

I have an input dataset whose records will be appended to an existing database. Prior to being appended, the data will go through heavy, time-intensive processing. I want to filter out records from ...
2
votes
1answer
26 views

How to compare a 'predicted' layer with an 'actual' layer for the same study extent?

I have developed a vector layer which predicts which polygons are more or less likely to experience coral bleaching. I now have another vector layer with the same extent with actual coral bleaching ...
3
votes
0answers
200 views

Python vs R for analzing spatial data [closed]

I am relatively new to both the python and R programming languages, having a small amount of exposure to both. Which language has the edge when working with spatial data and when would you use R over ...
0
votes
2answers
114 views

Is there a way to use IN filters in OpenLayers?

Is there a way to use IN filters (like the IN operator from SQL) in OpenLayers 2? For example, let's say, I want a filter like this: city = 'Paris' OR city = 'London' OR city = 'Lisbon' In ...
1
vote
0answers
49 views

Tool, API of or code samples for calculating spatial similarity between Lines

I am migrating a database with a road network to an other external data provider. We have joined our own data about roadworks, temporary speed-limits, etc., using ID and linear referencing on this ...
0
votes
1answer
89 views

chi-squared for two rasters in R

I am kind of new with statistics. I have two raster with categorical values and I want to get chi-square. How can I do this using R? Rasters have the same region and same resolution. Is chi-square ...
2
votes
1answer
163 views

Segment matching on a polyline

I have about 1000+ running routes which I can load into memory as polylines using latitude and longitude data captured from a running watch. From these polylines I would like to be able to identify ...
3
votes
2answers
134 views

How to compare a classified raster dataset to another polygon dataset?

I am going to perform an unsupervised classification on my dataset and will get a map as a result. The objective is to rebuild an already existing map (of different soil types) with my new dataset. ...
0
votes
1answer
47 views

Road network comparisons - how to extract roads that do not completely fall within the buffer

I am trying to compare how well one road network aligns with another - I have created a buffer around the first network and would like to select only the roads from the second network that fall ...
0
votes
1answer
431 views

How to compare two feature classes on one field?

I have two feature classes: an old one and a new one that I want to compare. Both feature classes have the same field structure and have a reference field 'ID' whose values are the same, except in ...
5
votes
1answer
429 views

how to compare geometries (contains, within) in arcpy?

I am trying to use 2 geometry objects to check if a line is within a (rather complex) polygon. The geometry check always fails, even if the line is clearly within the polygon. I use the following ...
3
votes
2answers
1k 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 ...
1
vote
1answer
95 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 ...
5
votes
3answers
142 views

Calculation based on features in shapefile

I hope I get the terminilogy right! Correct me if I mess something up. I need to perform some calculations for a scoring system for different habitat types. The Problem is that I have two different ...
0
votes
1answer
54 views

Comparing routes

I am looking for a way to compare routes of 2 or more persons to be taken by car. Person 1 has a starting point A1 and a destination point A2. Person 2 has a starting point B1 and a destination ...
0
votes
1answer
813 views

How to use “this” Levenshtein Python code into ArcGIS 10

I need some help with this: First of all, I wanted to "Compare strings from two fields", and asking before at gis.stackexchange, in this post someone help me with this topic, referring me to a Python ...
2
votes
1answer
992 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
5answers
238 views

Looking for simple software to compare two Landsat Images

At uni I used ERDAS imagine to view two rasters at the same time and it had various viewers for comparing them. I'm looking for something that has a slider so that I can see the differences between ...
1
vote
1answer
756 views

Bentley Microstation in comparison to ESRI ArcMap : Filetypes and Capabilities

I'm curious if there is a side-by-side comparison of Bentley's Microstation v8i (Select series 3) with ESRI's ArcMap 10.1 showing capabilities and filetype acceptance. I have heard some conversations ...
6
votes
3answers
158 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 ...
2
votes
1answer
232 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 ...
17
votes
4answers
4k views

What python web-mapping framework to use?

I am interested in developing a web-mapping application. I am relatively familiar with Python and so i'm looking for a python framework. What are my options? what are the pros and cons of each option? ...
2
votes
1answer
98 views

resampled thematic map accuracy

I've generated a map of ecoregions based on some environmental data using a semi-supervised classification where I combined a statistical clustering with random forests to generate my map. I created ...
2
votes
0answers
134 views

How easily can you pick up ArcGIS for Desktop if currently learning through QGIS on a Mac? [closed]

I'm currently trying to teach myself GIS and I have some really basic questions. I apologize if this has already been asked, but I have yet to find an answer to my question. So since I use a mac and ...
2
votes
0answers
38 views

How successful are current metadata implementations in achieving its objectives

Metadata infrastructure is well established as an essential practice within the GIS community. Quoting from the FGDC: Metadata helps people who use geospatial data find the data they need and ...
1
vote
0answers
503 views

How to compare files in two folders? [closed]

I'm pretty new user of ArcGIS. My intention is compare files (csv) from one folder with files in another folders. In those folders exist files with the same name but in second folder files have ...
5
votes
2answers
221 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 ...
2
votes
1answer
280 views

Easiest way to find spatial differences between Polyline shapefiles

I run into this problem a lot. I have two polyline's and I need to test for Spatial differences in them. Usually I use Erase and I have my answer, but on this PC I now only have access to ArcGIS Basic ...
5
votes
3answers
576 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 ...
0
votes
1answer
113 views

Comparing ShapeFile Data in C# [closed]

I have made a List containing all the original data (.shp files), and I have another List containing the modified data. I basically want to check all the modified file data against the original... So ...
0
votes
3answers
7k views

How to compare differences in two shapefiles? [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 ...
2
votes
1answer
489 views

Compare two Digital Elevation Model (DEM)

I would like to know what's the best method(s) to compare two DEMs without using any GUI soft like QGIS or ArcGIS. I'd like to do it in Python or C++, with GDAL or other similar lib. Does calculating ...
8
votes
1answer
963 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 ...
8
votes
2answers
275 views

How to efficiently (programmatically) determine whether two datasets have / don't have identical content?

Given: a geodatabase A that contains 100 datasets named a1 .. a100 a geodatabase B that contains 100 datasets named b1 .. b100 I want to programmatically (*) determine for each dataset pair (ai, ...
4
votes
1answer
109 views

Is there a tool to compare ArcGIS Desktop configuration on two pieces of hardware?

I have two PCS with ostensibly the same configuration (i.e. both ArcGIS Desktop 10.0 SP5, both 4Gb RAM) yet when I load the same file geodatabase onto both and run the same large (400 element) model ...
9
votes
2answers
362 views

Tools to compare unversioned copies of geospatial data

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 ...
0
votes
0answers
425 views

What is difference between Geo BI (Geo-business Intelligence) and GIS (Geographic Information System)?

I tried finding information with difference between Geo Business Intelligence and Geo IS but unfortunately no clearly answer being found. What is different between Geo BI and GIS and its ...
0
votes
2answers
108 views

I am looking for a list of mapping libraries? [closed]

I am looking for the top APIs that I can use to display maps from a number of map servers/sources. (like openlayers and openscales). So are there any other popular APIs for other languages than ...
3
votes
1answer
890 views

Does MySQL only support bounding boxes calculations instead of the real polygon geometry?

Within our company we are deciding which DBMS we will use to store spatial data. IT wants MySQL with the Spatial extension because there is already knowledge about handling MySQL DB. We are doing ...
5
votes
1answer
740 views

What is the Market share for open source web-GIS systems?

I would like to know the market share of 3 web-GIS systems, deegree, GeoServer, Geomajas). Which one is more popular? Are there any evaluations regarding the market share of open source web-GIS ...
5
votes
0answers
359 views

Can Quantum GIS replace Proprietary GIS? [closed]

I’m an MSc GIS student in the final year of my studies. I’m researching for my dissertation project which is entitled ‘Can Quantum GIS replace Proprietary GIS in large organisations?’ I’m primarily ...
-4
votes
1answer
447 views

Looking for a user-friendliness & functionality comparison for ArcGIS and QGIS

what is a user-friendly (ease of use) and functionality comparison for ArcGIS and QGIS? derived from Which topics are fundamental for ArcGIS? QGIS and gvSIG comparison
2
votes
0answers
371 views

ArcGIS/arcpy: Geometry object comparison methods not working. Do they take z values into account?

I have an arcpy script that makes calculations based on an input PolygonZ feature class. What I need to do in several places in the script is test whether a point falls within a polygon in 2D. In ...
2
votes
1answer
143 views

Compare workspace schemas in Modelbuilder

My model has two model parameters: A file gdb workspace or sde workspace containing the data An empty "template" file gdb As the very first process in my model, I want to check if the schema of ...
3
votes
1answer
2k views

How to compare 2000 Census block group data with 2010 block group data?

I want to calculate the percent change for median household income in Los Angeles at the block group level from 2000 to 2010. Someone told me I have to reaggregate 2000 block data to 2010 block group ...