On Jun 27, 2012, at 8:17 PM, Rahkonen Jukka wrote: > Hi, > > The question, if I understand is correctly, is relevant. In EPSG:4326 > shortest distance between two points is better expressed as a curve than as a > straight linestring. However, Mapserver does not support curves of any kind.
Interesting spin; didn't think of that. However, note that, as Brent pointed out, the OP is SELECTing the same coords twice, so, in effect, they are two coincident points of line length zero. > > You may find some workaround from GDAL. Ogr2ogr is having a "segmentize" > option for this purpose. It does not support real curves either, but it > creates intermediate points so that linestrings are shorter and thus follow > the curve better. See http://gdal.org/ogr2ogr.html > > -Jukka Rahkonen- > >> -----Alkuperäinen viesti----- >> Lähettäjä: [email protected] >> [mailto:[email protected]] Puolesta Mr. >> Puneet Kishor >> Lähetetty: 27. kesäkuuta 2012 17:39 >> Vastaanottaja: juliap >> Kopio: [email protected] >> Aihe: Re: [mapserver-users] Curved Lines >> >> >> On Jun 27, 2012, at 2:13 AM, juliap wrote: >> >>> Hi all, >>> >>> I have the following layer of type line : >>> >>> LAYER >>> NAME line >>> STATUS ON >>> TYPE LINE >>> CONNECTIONTYPE OGR >>> CONNECTION >> "MSSQL:server=server;database=database;uid=id;pwd=pwd" >>> DATA "SELECT geometry::STLineFromText('LINESTRING (' >>> +CAST(Geo.STX AS VARCHAR(54)) >>> +' ' >>> +CAST(Geo.STY AS VARCHAR(54)) >>> +', ' >>> +CAST(Geo.STX AS VARCHAR(54)) >>> +' ' >>> +CAST(Geo.STY AS VARCHAR(54)) >>> +')' >>> ,4326) >>> FROM column WHERE DATEDIFF(mi, CreatedON, >> CURRENT_TIMESTAMP) <='%x%'" >>> CLASS >>> STYLE >>> WIDTH 3 >>> SIZE 1 >>> COLOR 0 0 128 >>> END # end of style >>> END # end of class >>> PROJECTION >>> "init=epsg:4326" >>> END # end of projection >>> END # end of layer >>> >>> I was wondering how to get a curved line from this data. I >> tried using angle >>> and gap, but I don't see any changes. >>> Any suggestions? >>> >> >> >> Your understanding of geometry is a bit off here. In a query >> result set, each row is a feature, and a line feature would >> be made up of two or points; a curved line feature, of >> course, would be made up of three or more points. >> >> What you are getting in the result set above is a bunch of >> features, each of which are a point repeated twice. I think >> what you really want is to create a single line feature from >> all these points. So, you would probably do some kind of an >> aggregate on these points. I don't know the functions >> available in SQL Server, but there must be an analog for >> Postgres's aggregate functions. You want to collect all the >> points and make a line feature from them, and then pass that >> to MapServer to draw. You could make a view that does all >> this, and then call the view from MapServer. >> >> Hope this helps. >> >> >> -- >> Puneet Kishor >> _______________________________________________ >> mapserver-users mailing list >> [email protected] >> http://lists.osgeo.org/mailman/listinfo/mapserver-users >> > _______________________________________________ > mapserver-users mailing list > [email protected] > http://lists.osgeo.org/mailman/listinfo/mapserver-users _______________________________________________ mapserver-users mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/mapserver-users
