spatial-index

We have a list of x,y pairs. Every pair represents a point on a 2D space. I want to find the closest point from this list, to a specific point xq,yq. What is the best performance-critical algorithm for this problem? Lisp of points is not going to change; which means I do not need to perform insertion and deletion. I want just to find the nearest neighbor of a target xq,yq point in this set. Edit 1: Thanks to all! As Stephan202 has guessed correctly, I want to do this repeatedly; like a function. An the list is not necessarily sorted (In fact I do not understand how can it be sorted? Like a

I'm having some fun trying to pick a decent SQL Server 2008 spatial index setup for a data set I am dealing with. The dataset is polygons, representing contours over the whole globe. There are 106,000 rows in the table, the polygons are stored in a geometry field. The issue I have is that many of the polygons cover a large portion of the globe. This seems to make it very hard to get a spatial index that will eliminate many rows in the primary filter. For example, look at the following query: SELECT "ID","CODE","geom".STAsBinary() as "geom" FROM "dbo"."ContA" WHERE "geom".Filter( geometry:

I have (what I think) is a simple Sql Server spatial query: Grab all the USA States that exist inside some 4 sided polygon (ie. the viewport/bounding box of a web page's google/bing map) SELECT CAST(2 AS TINYINT) AS LocationType, a.Name AS FullName, StateId, a.Name, Boundary.STAsText() AS Boundary, CentrePoint.STAsText() AS CentrePoint FROM [dbo].[States] a WHERE @BoundingBox.STIntersects(a.Boundary) = 1 It takes 6 seconds to run :( Here's the execution plan.... Removed And the stats on the Filter operation... Removed Now, I'm just not sure how to debug this .. to figure out what I need to

I'm looking at implementing spatial queries in .NET without using SQL2008. The first requirement is to be able to create a (BTree styled) spatial index and be able to query it. Although SQL 2008 ships with .NET libraries for the types, you need to use SQL for the spatial indexes. HAs anybody used any .NET libraries for spatial data (OS or commercial)? I am looking at NetTopologySuite but it looks quiet and I don't want a dead library. SharpMap is a (well known and used) OpenSource collection of spatial libraries for .NET http://www.codeplex.com/SharpMap Commercial libraries from ESRI would be

Given n points in d-dimensional space, there are several data structures, such as Kd-Trees, Quadtrees, etc. to index the points. On these data structures it is possible to implement straight-forward algorithm for nearest neighbor queries around a given input point. Is there a book, paper, survey, ... that compares the theoretical (mostly expected) runtime of the nearest neighbor query on different data structures? The data I am looking at is composed of fairly small point clouds, so it can all be processed in main memory. For the sake of simplicity, I assume the data to be uniformly