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51

There are at least two different kinds of heat maps: Heatmaps representing concentration of points, and Heatmaps representing distributions of attribute values Every method has advantages and problems, I'm afraid going into detail is far beyond this Q&A. I'll try to list some methods and functions for QGIS and GRASS. Concentration of points If you ...


27

I use both gvSIG and Qgis. In my view it is VERY difficult to say which one is the best. BOTH are very useful and, most of all, IMHO, they are complementary. This is the boon of using open source softwares: you can try them without spending anything! This is my personal list. I am fully aware it is very subjective: please, bear with me... gvSIG pros: ...


16

While I like heat maps, I realize they are often mis-used. Typically what I've seen is a process whereby the color of each pixel is based on the result of an inverse distance weighted function applied to a collection of points. Any time a map has a lot of overlapping point markers, I think it is worth considering a heatmap. Here's a web based api. ...


15

Statistically, here is how you should go about doing a heat map: 1) Integrate point features. The idea of integration is to take points that should be considered coincident and merge them together as a single location. I like to use nearest neighbor analysis and use an appropriate value from there. (For example, when doing a crime heat map, I use the ...


8

What regional settings do you have? Take a look at this nice youtube video: How to change gvSIG language


8

For simple heat maps and generating countour lines I've used QGis with the Grass intergration: Load data-points Load a limiting shape – eg county boundary Create a Grass mapset Open the Grass toolbox and click on the module list to search for each tool Load v.in.ogr.qgis module and load both the point data and the boundary shape, each time remembering to ...


7

Can you get your dwg as dxf? then can use the QGIS plugin DXF2Shp If you download FME Beta (for trial) that WILL work very well.


7

I have much more experience with QGIS, but coincidentally just recently I decided to give gvSIG a try. Below some observations, some of which are different from answers from others. My guess is that this is at least partly related to the platform and perhaps memory configuration (especially if you work on Windows). I am running both on Linux (Ubuntu 11.04). ...


7

Refractions Research has made a Line Cleaner tool that seems to do what you want. Line Cleaner cleanses networks by simplifying complex, cyclical, very short and zero-length geometries, and removing pseudo-nodes and insignificant vertexes. Most significantly, in the cleansing phase, it is able to ensure that feature matches can be considered ...


6

Talking about free softwares, the dynamic of the community could also be an argument of choice for using one or another. That document benchmarks gvSIG/Qgis and GRASS regarding the community aspects (see english summary of paper here). I would say it is interesting but has to be read with precaution. Taken indicators to analyze the community participation ...


5

Here a generic soluion, that you can impĺement with PostGIS or any other OGC-compliant software. NOTE: as I say before, a key concept in FOSS and GIS is standardization: the best solutions adopt standards, like OGC ones. Your problem is to "find pseudo nodes"... But I think that it is a little more, "find non-pseudo nodes and join lines of pseudo ...


5

And we can't forget the powerful integration of Qgis with GRASS GIS via the Qgis-GRASS plugin!


4

I have no experience with gvSig or Kosmo, however I programmed applications for uDig and reused components of Openjump. From a software engineering perspective uDig proposes a neat platfor supported by Eclipse, an universal tool for serious developers. However, developing for uDig is cumbersome precisely because of the important role the Eclipse framework ...


3

If you have trouble accessing the preferences (I can imagine that if your interface is in Russian) you can just edit your $HOME/gvSIG/andami-config.xml where you have to change the value of the attribute "locale-language" to "en" for example. See screenshot:


3

Relima; I've had this same quest for a while now, I've managed to do it relatively easy with Kosmo in X simple steps: Convert dwg to dwg 2000 with Teigha File Converter fro the Open Design Alliance; Open this dwg in Kosmo; Save it as an ESRI Shape file, as you mention it will create 2 or 3 shapes point, polygons and lines; Select elements by the field ...


3

Consider ogr2ogr ( http://www.gdal.org/ogr2ogr.html ) for future data conversion needs. It is part of the ogr ( http://www.gdal.org/ogr/ ) project. This is a command line utility to will convert to/from just about anything ( http://www.gdal.org/ogr/ogr_formats.html ). From the website: "This program can be used to convert simple features data between file ...


3

Well, as far as I saw using both QGIS and gvSIG, either have an equal value. But, your choice is dependent upon on what you want to do. QGIS is a complete application in order to working on GIS and it's supported by a large community. But if you need a portable GIS application (that runs on the stick, eventually) or you want to get support for MrSID files ...


3

Qgis right now is also lighter. But for heavy operations, I find gvSIG more useful. The right question you should ask is: what do I want to do? Viewing, editing or geo-calculate heavy stuff?


3

As suggested by simo, I posted this question onto gvSIG mailing list and got the following answers/links: This discussion archive can also be read in context at Nabble: gvSIG advantages gvsig uses sextante as raster processing framework. Take a look at what you can do with it: http://sextantegis.blogspot.com/, http://sextante.forge.osor.eu/ ...


3

I've used a little bit both the products, so give the right importance to my words. The first thing that you can experiment is that working with large base data with QGis is almost impossible, due to low performances. GVSig is extremely faster, and used a "paginated" rendering that is very cool when you're working. GVSig used an UI approach that (my2cents) ...


3

gvSIG uses the same CRS library than QGis, is called Proj4. In order to load the data you have to: Create a view in 26971 EPSG code (I guess). See http://i.imagebanana.com/img/ardsef2u/20130304115816Seleccin.png Load your data and go to the change source transformation. See http://i.imagebanana.com/img/jwjchwo6/20130304120019Seleccin.png Select the EPSG ...


2

gvSIG also has a portable version packaged by Cartolab. As one of the developers of NavTable and OpenCADTools, i mostly agree with Silvio's analysis. gvSIG is more robust and has much better performance than Qgis, but i think that qgis has a more configurable gui.


2

That manual is really old and outdated. If you want to set up a gvSIG 1.x workspace you can check this. It's not updated for 1.12 but more or less the process is OK. If you want to develop with gvSIG 2.0 then you have two situations, it's not the same to develop a gvSIG plugin than working with the core. For the first case you don't need to set up a ...


2

There is a command line option that you can use to start gvSIG in the language that you want: -language=ISO_CODE_FOR_THE_LANGUAGE In linux to launch gvSIG in English you can use ./gvSIG.sh -language=en


2

gvSIG doesn't have a driver for SQL Server at this moment, at least there isn't at project level. Yes you can connect through ODBC for alphanumerical data, but there is no driver for the geometry or geography data types.


2

I'm afraid yo can not import a folder of tiles recursively. In gvSIG 2 that will be quite easy to perform. Right now you can load any number of files from a particular folder with the typical "add data" dialog.


2

Non-Free solution: FME + MRF + SmartCleaner transformer Free solution GRASS v.clean (Latest QGIS 1.8.0 with GRASS tools is easiest way to use it) and other topology cleaning tools


2

Sorry, Eva, but that is not possible in a easy way: gvSIG is a desktop software, so it has no webs service to share your project or views. On the other hand, I can advise you some solutions depending on what you really need: Static information: Export your views as image or PDF. Share a layer: You can export your layer as KML and load it in google Maps or ...


1

If you get the "wide" version, you see coordinates in lat/lon, which is distorted. To get a right picture, you can set almost every projected as project CRS suited for your area. With a UTM or a global projection like Google Mercator EPSG:3857 give a silimar picture. The layer CRS still remains to be lat/lon EPSG:4326. It should not matter whether you do it ...


1

Here are steps to Find your pseudo nodes using OpenJump a free GIS. QGIS and gvSIG have the Sextante Plugin, so these same steps should work their too, the Spatial Join might be slightly different. I used version 1.2 for testing. -- save the Line endpoints Sextante toolbox, Topology, Extract endpoints of lines -> endpt_0 -- unsplit your lines Sextante ...



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