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30

Sorry, the answer is no. You have to roll out your own field mapper and only software that uses your mapper will understand it. You could use other formats that do not have this limitation though (e.g. filegdb, spatialite, etc). UPDATE: Some word of advice about the workarounds from personal experience. When people choose shapefiles (and insist on them) ...


14

Answer can be found from the official specification http://www.esri.com/library/whitepapers/pdfs/shapefile.pdf. All the non-Null shapes in a shapefile are required to be of the same shape type. The values for shape type are as follows: Value Shape Type 0 Null Shape 1 ...


12

A few ideas come to mind for building your geospatial programming credentials: Create a legacy of solutions and answers on GISse and Stack Overflow. You will notice that many people on GISse creatively and wisely use this forum to further their freelance work. Create a web page or blog to show potential employers what you know. Some of my favorites, and ...


11

There is a standard way to deal with this, although your clients might not be completely happy with it: you export two files, a shapefile and a data file in a format their software can read. The shapefile has only a unique identifier, [Id], for attributes. The data file has several attributes: [Id] to match the shape, [Field] to provide the field name, ...


9

It looks like there was a fork that was intended to be reintegrated, but this never happened. In response to the deteriorating quality of some GeoTools code base, Martin Desruisseaux embarked on a major cleanup effort. In July 2008, Martin created a new, initially empty, source code repository and proceeded to copy the GeoTools classes to ...


9

A shapefile does not support mixed geometry. A shapefile either consists of points, polylines or polygons, but not more than one. See this article for more: Shapefiles


8

I think the way that we create mapping applications is changing fast and the key to success in this industry is being ahead of that curve. For example 10+ years ago when we wanted a blog we get a shared hosting solution, download a blogging platform like Wordpress or Movable Type install it on the server, buy a domain name, install a theme, bang our head ...


7

You could use the "proper" ellipsoidal Mercator (EPSG:3395). That projection is truly conformal, as opposed to the "Web Mercator" (EPSG:3857), which uses a spherical approximation. This comes at a computational cost, however (about a factor of 5 for the forward and reverse projection, according to the table on slide 10 of Noel Zinn's presentation). Also, ...


5

hallo first, in the post in stackoverflow the discussion is about getting a GPS point and say if it is a building or a road. AFAIK, GPS does not have that precision. I never expect a GPS point to be more precise than 10 meters. of course it often is a little better than that but it can also be much more wrong. In Routing GPS units the software often snap ...


5

For Java, I'd recommend JTS Topology Suite. There is both a "Nearest Point" and "Closest Point" routine (I'm not sure if it is the same, or was renamed between versions) that does what you want. The result from the above is LINESTRING (205 305, 250 300), so the first point of the result is your closest point coordinates, and the length property of the ...


5

The units of measurement is based on the underlying spatial reference. So, for example, if it is EPSG:4326 it is decimal degrees or if it EPSG:2037 it is meters.


5

download gt-mongodb,like gt-mongodb-9.2.jar and put the file at: apache-tomcat-6.0.30\webapps\geoserver\WEB-INF\lib . download mongo for java ,like mongo-2.9.1.jar . add it to classpath ,such as C:\apache-tomcat-6.0.30\lib\mongo-2.9.1.jar . and restart your computer and start your tomcat. you will see the mongodb at geoserver->stores.


5

CoordinateReferenceSystem is the base Interface from which all other GeoTools SRS are derived from - it is the base class of Geocentric and Geographic projections (and others with vertical and temporal coordinates). It comes from the ISO19111 specification by way of the OGC GeoAPI project. CoordinateSystem is also an interface that comes from ISO19111 and ...


4

The answer depends on how the question is interpreted. One interpretation is, "Given that a GPS point is known (or assumed) to lie either on a building or on a road, what are the odds that it lies on the road?" To find this, compute a grid representing a 2D Gaussian function whose standard deviation equals the expected error in the GPS position. Use a ...


4

You can also look at http://svn.osgeo.org/geotools/trunk/modules/library/xml/src/test/java/org/geotools/GMLTest.java to see how the tests do it. The key section seems to be: GML encode2 = new GML(Version.GML2); encode2.setBaseURL(baseURL); encode2.setNamespace("location", "location.xsd"); encode2.encode(out2, collection); out.close(); ...


4

Maven can only handle libraries that are deployed on a maven repository, and Opencarto is not deployed anywhere, so you cannot get it with maven. To use it, you may use one of these methods: you download an opencarto jar from there and include it in your eclipse project (you also need jts, xstream and xpp3_min) you checkout the snapshot version of ...


4

Is this what you're after? http://weblogs.java.net/blog/cajo/archive/2010/10/16/adding-google-maps-your-java-application You can also use Bing maps with Java, also worth looking at GeoTools NASA Worldwind OpenMap There's also a useful list of OpenSource Java GIS software here: http://java-source.net/open-source/geospatial


4

I've created a while ago a method to draw points on a layer from geotagged flickr pictures. It shows basically how to create a FeatureLayer with custom points public Layer getFlickrLayer(){ SimpleFeatureTypeBuilder b = new SimpleFeatureTypeBuilder(); b.setName( "pictures" ); b.setCRS( DefaultGeographicCRS.WGS84 ); //picture location ...


4

GeoTools provides a GeoJSON module which will read in GeoJSON files and convert them to GeoTools Feature Collections - the geometry elements of these collections is stored as a JTS object. So all you need is Geometry geom = (Geometry) feature.getDefaultGeometry();


4

A couple of options: Convert the PostGIS layer to a shapefile in QGIS (save-as), then use the Vector|Conversion|Rasterize tool; Use the gdal_rasterize command directly. For the second option: gdal_rasterize -a VAL -ts [x] [y] PG:'host=localhost dbname=DB user=USER' -sql "SELECT the_geom, VAL FROM table" out.tif Where: VAL = the value to assign ...


4

I suggest to use an oblique mercator projection as I explained in Using customized Coordinate System for Archaeological site data You have to define the origin in lon and lat WGS84 degrees, and the rotation against true north.


4

You need to import the GeoJSON plugn <dependency> <groupId>org.geotools</groupId> <artifactId>gt-geojson</artifactId> <version>${geotools.version}</version> </dependency> and then call it like this (a full example is here): public String geoData() { final GeometryBuilder builder = new ...


3

GeometryFactory geomFac = JTSFactoryFinder.getGeometryFactory(null); or GeometryFactory geomFac = JTSFactoryFinder.getGeometryFactory(GeoTools.getDefaultHints());


3

You'll need to add a WMS layer for your background map. The GeoTools tutorial has sections on adding WMS layers and querying databases (Example uses a PostGIS database). You might want to check them out.


3

The KML support is tied into the XML facilities for encoding and parsing geometry. The GeoTools user guide has replaced the wiki links provided by Ian above - with a nice clear page devoted to wrangling geometry and XML: http://docs.geotools.org/latest/userguide/library/xml/geometry.html One of the headings on that page is devoted to KML ...


3

There is a KMLExample at http://svn.osgeo.org/geotools/trunk/demo/example/src/main/java/org/geotools/demo/xml/KMLExample.java which shows the KML bindings in use for writing. From other discussions on the user list it seems that the KML bindings work in a similar way to the GML bindings so look at http://docs.codehaus.org/display/GEOTDOC/GML+XML+Support for ...


3

I haven't got a full answer but an important point is the context of the building and the road. GPS accuracy falls dramatically in a very built up area because the radio signals are obscured by and bounce off buildings. So GPS readings in the country by a low building will be far more accurate than in a skyscaper 'canyon' as you get in major cities.


3

There is example code on using the GeoTools CRS module at http://docs.geotools.org/stable/userguide/examples/crslab.html which shows how to make the transformation if you know the EPSG codes of the two projections you want to use. If you don't know the EPSG codes then you can look them up at http://spatialreference.org, if however the code you want doesn't ...



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