Spatial

I am working with shapefiles in R , one is point.shp the other is a polygon.shp. Now, I would like to intersect the points with the polygon, meaning that all the values from the polygon should be attached to the table of the point.shp. I tried overlay() and spRbind in package sp, but nothing did what I expected them to do. Could anyone give me a hint? Spacedman If you do overlay(pts, polys) where pts is a SpatialPointsDataFrame object and polys is a SpatialPolygonsDataFrame object then you get back a vector the same length as the points giving the row of the polygons data frame. So all you

When measuring the distance between two locations using the DbGeography.Distance(otherLocation) what is the unit of the distance? Even the msdn information and the intellisense fails to specify the unit of the distance. Anyone knows? [edit] I'm using srid 4326. which most examples seems to use. From what I can find, 4326 seems to be radians, this leaves me completely clueless. radians are used to measure angles/degrees so what does this mean in reality ? Sign Several articles seem to agree on meters being used in 4326 as the unit of distance. WGS 84 is done in meters as well, which is probably

I've got a system which basically has to do a query like this: SELECT * FROM MyTable WHERE @parameter.STIntersects(MyGeometryColumn) This is quite simple to do when using vanilla SQL parameters, you just have to create your parameter in a non-typical way (where the builder variable is a SqlGeometryBuilder which I use to create a rectangle): command.Parameters.Add(new SqlParameter { UdtTypeName = "geometry", Value = builder.ConstructedGeometry, ParameterName = "@paremeter" }); Now, When I try to do this using dapper, I get an error that it can't figure out how to use this as a parameter. Anyone

currently I'm using the build in function dist to calculate my distance matrix in R. dist(featureVector,method="manhattan") This is currently the bottlneck of the application and therefore the idea was to parallize this task(conceptually this should be possible) Searching google and this forum did not succeed. Does anybody has an idea? Will Beason Here's the structure for one route you could go. It is not faster than just using the dist() function, instead taking many times longer. It does process in parallel, but even if the computation time were reduced to zero, the time to start up the

I have a 3D pointcloud and I'd like to efficiently query all points within distance d from an arbitrary point p (which is not necessarily part of the stored pointcloud) The query would look something like Pointcloud getAllPoints(Point p, float d); what accelerationstructure would be appropriate for this? A range-tree seems to be appropriate only for querying rectangular volumes, not sphere volumes (of course I could query the boundingbox of the sphere and then sort out all vertices that have larger distance than d - but maybe there is a better way to do this??) thanks! according to Novelocrats

I have (again) a problem with combining data frames in R. But this time, one is a SpatialPolygonDataFrame ( SPDF ) and the other one is usual data.frame ( DF ). The SPDF has around 1000 rows the DF only 400. Both have a common column, QDGC Now, I tried oo <- merge(SPDF,DF, by="QDGC", all=T) but this only results in a normal data.frame, not a spatial polygon data frame any more. I read somewhere else, that this does not work, but I did not understand what to do in such a case (has to do something with the ID columns, merge uses) oooh such a hard question, I quess... Thanks! Jens Let df = data