[postgis-users] errors while using st_dwithin

[Paul Ramsey]

Ah. Geography is version 1.5+
You can put st_distance_spheroid in place of st_distance for a metric answer.
p

On Thu, Dec 6, 2012 at 9:40 AM, tasneem dewaswala
<tasneem.europe at gmail.com> wrote:
> Thank you for the suggestion
>
> i tried to use ST_GeographyFromText and ST_GeogFromText
> but it gives an error as the function does not exist.
>
> is this because of version problem.
>
> My postgre version is
> "PostgreSQL 8.4.14, compiled by Visual C++ build 1400, 32-bit"
>
> and postgis version is
> "POSTGIS="1.4.2" GEOS="3.2.0-CAPI-1.6.0" PROJ="Rel. 4.6.1, 21 August 2008"
> USE_STATS"
>
>
> On Thu, Dec 6, 2012 at 10:29 PM, Paul Ramsey <pramsey at opengeo.org> wrote:
>>
>> If you want to use angular units (lon/lat) but get back metric
>> results, use the geography type, not the geometry type.
>> ST_GeogFromText
>>
>> On Thu, Dec 6, 2012 at 8:56 AM, tasneem dewaswala
>> <tasneem.europe at gmail.com> wrote:
>> > When i locate this two co-ordinates on google map.
>> >  one lat/lon (19.235308 72.977955) is in India while
>> > another (56.6647756667,12.877464) is in Sweden,
>> > so how can the distance between both of them be 70 meters ?
>> >
>> >
>> > On Thu, Dec 6, 2012 at 9:30 PM, Duncan Golicher <dgolicher at gmail.com>
>> > wrote:
>> >>
>> >> The points look about 70m apart to me.
>> >>
>> >> Duncan
>> >>
>> >>
>> >>
>> >> On Thu, Dec 6, 2012 at 8:47 AM, tasneem dewaswala
>> >> <tasneem.europe at gmail.com> wrote:
>> >> > Hello,
>> >> >
>> >> > i want to know whether two location's are within 100 meters range of
>> >> > each
>> >> > other or not.
>> >> > i tried using ST_DWITHIN, but its not giving me appropriate answers.
>> >> >
>> >> > my query is "
>> >> >
>> >> > select st_dwithin(ST_GeomFromText('POINT(19.235308
>> >> > 72.977955)',2163),ST_GeomFromText('POINT(56.6647756667
>> >> > 12.877464)',2163),100) as "result";
>> >> >
>> >> > the result that i get is "t" i.e true, which is logically not
>> >> > correct,
>> >> > the
>> >> > answer i should get is false, since two locations are far beyond 100
>> >> > meters
>> >> > range.
>> >> >
>> >> > Please help me forming an exact query for this.
>> >> >
>> >> > Regards
>> >> > Tasha
>> >> >
>> >> >
>> >> > _______________________________________________
>> >> > postgis-users mailing list
>> >> > postgis-users at lists.osgeo.org
>> >> > http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users
>> >> >
>> >>
>> >>
>> >>
>> >> --
>> >> Dr Duncan Golicher
>> >> Investigador Titular,
>> >> El Colegio de la Frontera Sur, Chiapas,Mexico
>> >> Mexico tel +52 1 967 137 94 20
>> >> Skype name duncangolicher
>> >>
>> >> Publications: http://www.mendeley.com/profiles/duncan-golicher
>> >>
>> >> Senior lecturer, Bournemouth University, UK
>> >> Centre for Conservation Ecology & Environmental Change
>> >> School of Applied Sciences
>> >> Christchurch House rm C218a
>> >> Bournemouth University
>> >> Fern Barrow
>> >> Poole (Dorset) BH12 5BB UK
>> >> Tel. +44 (0)1202 961682
>> >>
>> >> For list of publications see Researcher ID:
>> >> http://www.researcherid.com/rid/B-4240-2009
>> >>
>> >> dgolicher at bournemouth.ac.uk
>> >> dgoliche at ecosur.mx
>> >>
>> >> Researcher ID:
>> >> http://www.researcherid.com/rid/B-4240-2009
>> >> _______________________________________________
>> >> postgis-users mailing list
>> >> postgis-users at lists.osgeo.org
>> >> http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users
>> >
>> >
>> >
>> > _______________________________________________
>> > postgis-users mailing list
>> > postgis-users at lists.osgeo.org
>> > http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users
>> >
>> _______________________________________________
>> postgis-users mailing list
>> postgis-users at lists.osgeo.org
>> http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users
>
>
>
> _______________________________________________
> postgis-users mailing list
> postgis-users at lists.osgeo.org
> http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users
>