Correct.
On 3 May 2012 10:07, Emmanuel Bernard <emman...@hibernate.org> wrote: > Let me see if I understood by rephrasing. I am trying to get a feel of where > conversions happen. > > I am assuming that this is mostly relevant for the boolean query approach and > the later circle memory filtering (ie that quad tree is not involved). > > Today we accept decimal coordinates from the user and store them as is in the > index. But to calculate the right rectangle and then circle filter when > we build a query and later filter elements in memory (circle): > > - we convert the query coordinates into radians to find the right box > boundaries coordinates and convert them back into decimals > - for each matching element in the box we further convert the coordinates in > radian to filter by circle > > In the new scheme where radians are stored, we would: > > - receive coordinates from the user as decimals > - convert them to radians once at indexing time and once at query time > > So the big difference would be that we avoid the per element in the box > filtering conversion from decimals to radians. > > Am I correct or completely wrong? > > On 3 mai 2012, at 10:12, Nicolas Helleringer wrote: > >> Hi all, >> >> Sanne and I have been wondering about the way the spatial >> branch/module/functionality for Hibernate Search shall store its >> coordinates in the Lucene index. >> >> Today it is implemented with decimal degree for : >> - easy debugging/readability >> - ease of conversion on storage as we want to accept mainly decimal degree >> from users data >> >> Sanne pointed out that when the search is done there is quite a few >> conversion to radians for distance calculation and suggested that we may >> store directly coordinates under their radians form. >> >> I have tried a patch to implement this and as I was coding it I feel that >> the code was less readable, in the coordinates normalisation mainly and >> that there was as many conversion as before. >> Conversions had moved from search to import / export of coordinates in and >> out the spatial module scope to user scope. >> >> What the docs does not tell (yet), is that we are waiting for WGS 84 (this >> is a coordinate system) decimal degree coordinates input, as these are >> quite a de facto standard (GPS output this way). >> >> Today this is not the purpose of Hibernate Search spatial initiative to >> handle projections. There are opensource libs to handle that on user side >> very well (Proj4j) >> >> So. The question is : shall we store as radians or decimal degree ? >> >> Niko >> >> P.S : Hope it is clear. If not ask for more. >> _______________________________________________ >> hibernate-dev mailing list >> hibernate-dev@lists.jboss.org >> https://lists.jboss.org/mailman/listinfo/hibernate-dev > > > _______________________________________________ > hibernate-dev mailing list > hibernate-dev@lists.jboss.org > https://lists.jboss.org/mailman/listinfo/hibernate-dev _______________________________________________ hibernate-dev mailing list hibernate-dev@lists.jboss.org https://lists.jboss.org/mailman/listinfo/hibernate-dev
