From: Robert W. <rob...@de...> - 2007-10-29 15:11:29
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Hi, We are currently looking for ways to do spatial calculations against records stored within an eXist database. Our records already hold address data and the sort of thing we want to do is to find records that have an address within a certain radius of a given point. I see that there is now a spatial extension module for eXist which has some interesting looking functions - but I am not too familiar with the workings of GIS so am unclear whether these functions are really what we want or what the prerequisites are for using them. I would be grateful for any pointers on this. Many Thanks Rob Walpole Devon Portal Developer Email rob...@de... Web http://www.devonline.gov.uk |
From: Adam R. <ada...@de...> - 2007-10-29 16:20:07
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So Pierrick has enlightened me a little on IRC, if I understand correctly. We place gml:coordinates in each of our documents, we then define a spatial index on this. When a user comes along we ask them their location (postcode of something) and resolve their co-ordinates. We then ask the spatial index for all documents within 10km of the users co-ordinated. Pierrick - what would be the best use of the spatial module functions to achieve this? Thanks Adam. On Mon, 2007-10-29 at 15:10 +0000, Robert Walpole wrote: > Hi, > > We are currently looking for ways to do spatial calculations against > records stored within an eXist database. Our records already hold > address data and the sort of thing we want to do is to find records > that have an address within a certain radius of a given point. > > I see that there is now a spatial extension module for eXist which has > some interesting looking functions - but I am not too familiar with > the workings of GIS so am unclear whether these functions are really > what we want or what the prerequisites are for using them. I would be > grateful for any pointers on this. > > Many Thanks > Rob Walpole > Devon Portal Developer > Email rob...@de... > Web http://www.devonline.gov.uk > > > ------------------------------------------------------------------------- > This SF.net email is sponsored by: Splunk Inc. > Still grepping through log files to find problems? Stop. > Now Search log events and configuration files using AJAX and a browser. > Download your FREE copy of Splunk now >> http://get.splunk.com/ > _______________________________________________ Exist-open mailing list Exi...@li... https://lists.sourceforge.net/lists/listinfo/exist-open |
From: Pierrick B. <pie...@fr...> - 2007-10-29 16:51:19
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Hi, Adam Retter a écrit : > We place gml:coordinates in each of our documents, we then define a > spatial index on this. I'do that before, in he collection's configuration... as usual. > When a user comes along we ask them their > location (postcode of something) and resolve their co-ordinates. Yes. That may be the most difficult point. > We then > ask the spatial index for all documents within 10km of the users > co-ordinated. Exactly. > Pierrick - what would be the best use of the spatial module functions to > achieve this? The provided link roughly shows everything you need : 1) create a buffer 2) compute an intersection (or a "within" spatial search, which is more restrictive) 3) if required, you might want to transform the data from one CRS to another one. [snip ;-)] Cheers, p.b. |