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11

Evaluation of the options Contour lines represent continuous surfaces, so their comparison ultimately is a proxy for comparing those surfaces. Because both the surface values (elevations) and locations are potentially subject to error, there are two components to the comparison: in terms of value and in terms of position. The two cannot be separated, ...


7

There is a nice matrix (table) about "Matrix on OSGeo and COTS (Commercial off-the-shelf) software functionality", see this online spreadsheet. The effort of compiling the table was led by Tom McConnell, various project leads contributed to it.


7

Benefit of using the ArcGIS Viewer for Flex application is that you get a flexible out-of-the box viewer with no coding and minimal configuration. There are also a number of widgets available for the viewer that you can use for extending your application. It is a great option for those looking to minimize the amount of time and effort required in setting ...


6

You could look at http://dotspatial.codeplex.com/ that has just released 1.0. From what I can remember this pulls together a number of other components such as Proj4 library and Topology suite.


6

Try Folium, it's really simple to get started: you create your project using Python and you just open the resulting map. If you want to go deeper, you can sort by descending level of simplicity: GeoDjango with additions like Django-Leaflet. Really best doc here FeatureServer More server side oriented but an OpenLayers demo MapFish alone. Based on now ...


5

Try PatchFinder from the ESRI Support site. Also before you go too far down that rabbit hole you might just uninstall and reinstall ArcGIS on the problem machine. It's likely not a reproducible error if it only happens in a 400-element model.


5

If you want to use Census tracts the good people at Brown University have already done the hard work for you: Brown University Longitudinal Tract Database This resource contains tract-level variables from 1970-2000 interpolated to 2010 boundaries, facilitating longitudinal analysis.


5

You can do row-wise comparisons in PostgreSQL with row constructors. I'm guessing that this would work with geometry fields but I haven't tried it. Given two tables where the matching features have the same id field in each you could do something like: select ROW(t1.att1, t1.att2, t1.geom) = ROW(t2.att1, t2.att2, t2.geom) from t1, t2 where t1.id = t2.id ...


5

What are the pros and cons of using the ArcGIS Viewer for Flex application as a starting point for GIS applications? Esri support will support the core viewer and the widgets that come with it (but not custom widgets). This is a huge reason to base your application around the viewer. Stop re-inventing the wheel and focus your development time on ...


5

it looks like there's a wee bit of confusion on what's greater/smaller than what but I'll leave that for you to manipulate. This solution will iterate ONLY ONCE through each table which will not confuse the cursors and will save you 10 million iterations(from loop in a loop iteration). Using a dictionary lookup is so fast it's considered 'free'. So populate ...


4

Ok, I found a tool myself: http://www.obviously.com/gis/shpdiff/ - see if I can make it work.


4

For raster formats, I think the Esri ASCII Grid format is most the commonly supported format across GIS software. Since it is ASCII, it is portable to read anywhere, even in a text editor. Many closed and open-source software (particularly recently developed) generally use GDAL, which has a native AAIGrid driver. The two drawbacks are the file size (but it ...


4

I've now done a little searching myself on this and there seem to have been a few academic papers published with comparisons. Even the newest one is a year+ old now, but they do make for some interesting reading. An overview on current free and open source desktop GIS developments (PDF) - Comprehensive comparison of GRASS 6.3.0, QGIS 0.9, uDig 1.1, gvSIG ...


4

Your assumption is pretty much correct. MySQL's spatial support is ... simplistic to say the least. It does work, but you'll find very few GIS applications support it. This isn't specific to just polygons, any spatial feature is more limited in MySQL because while it does store them in the same way (WKB), there simply aren't as many functions to manipulate ...


4

How about GeoDjango ? It might be overkill for what you want to do but it seems to meet the criteria you are looking for. It's a python driven web framework that incorporates a lot great GIS projects like, gdal/ogr, OpenLayers, and supports the use of geodatabases including postgis/postgres. I've been experimenting with it off and on for a few months and ...


4

If you want basic webservice in python, there is two way : geodjango, this is an official extension integrated in django. It works great but it's django centric. If you like django it's perfect flask (or an another webframework) + geoalchemy2 (extension of sqlalchemy) + shapely (lirairy for manipulating Geo-object) , maybe it's harder than geodjango but ...


4

As the doc says ~= only compares bounding boxes. So if you move a point in a way that it doesn't change the bounding box ~= still returns true.


4

You need to nest your search cursor loops to iterate through both at the same time, while relating the rows in some way (so arcpy knows when it is at the right one, and will stop looping to compare the value). Luckily you've got those matching ID fields already. This should get you started comparing the area values. Let me know if it doesn't run or I've ...


3

If you can get a hold of the X-Ray for ArcCatalog add-in (link currently broken for me, the author's site is here if you want to contact them directly), I remember seeing a Python implementation of XML workspace document import/export tools. There is also the Table Compare tool which you can set to do a schema-only comparison between two tables; you could ...


3

There's a similar question, but not doing it with a programming language. here's a small python snippet which checks the difference between two numpy matrixes. a = np.random.randint(-10,400,(500,500)) # or gdal.Open("path/to/raster").GetRasterBand(0).ReadAsArray() b = np.random.randint(-10,400,(500,500)) dif = abs((a-b)/(b+1e-5))<0.05 ...


3

I've had good results with this script: Change Detector


3

I co-wrote a study on GRASS, gvSIG and QGIS communities, which may be an useful companion to other technical and economical studies. Actually, it compares the 3 reference desktop GIS applications as seen by OSGEO, but the scripts to generate the statistics have been released as free software, so you should be able to tweak them to analyze other environments ...


3

I think you might be best off considering whether you should use a range of metrics. Some users may consider the average spatialite error to be of concern, but a bigger concern is "how bad does it get". You are presumably looking at this in at least some respect (e.g. temporal vs spatial), I'm just suggesting looking very widely. I don't have all the ...


3

There is a Feature Compare tool in the Data Management Tools > Data Comparison toolbox. Here is the link to the Desktop 10 help page. Script examples in Python is available at the bottom of the page. I haven't used the tool myself (that I can remember anyway) so I'm not sure if it will generate the output you are looking for. Might be worth a look.


3

I have to mention this custom tool. It's called ChangeDetector, and works pretty well in my experience for finding changes between file versions. It'll output three (or less) shapefiles with new, deleted and unchanged features. It is also possible to define which fields to compare (eg. Shape and/or attribute fields of your choice).


3

It does seem that the "[test] for actual geometric equality of the two features" is missing from later versions, but according to this article from Boundless (formerly OpenGeo), the function ST_Equals can be thought of as testing for "exact equality" even though, according to the documentation, it does not make this comparison vertex-to-vertex. For ...


3

I use both and I'll explain why. I should note I use Select Series 2. These are the two pieces of software we use almost exclusively at my workplace to conduct lidar data processing. I have over five years experience using both and I think of them, at least in our particular product and work, to be complimentary to each other. However, the role of ...


3

I have not tried it but Opticks is worth a shot: http://opticks.org/confluence/display/opticks/Welcome+To+Opticks


3

First of all, you should compare your string in a case insensitive way. EDIT: I also add .strip() in case you have blank spaces in your string. POI_name.lower().strip() == ROTULO.lower().strip() Because Python is case sensitive and ROTULO is in capital letter For further comparison, this is more a Python question. For instance, have a look at this post ...


2

The function ST_Equals(geometryA, geometryB) returns TRUE if they are spatially equal.



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