[postgis-users] errors while using st_dwithin

[Paul Ramsey]

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
>> >
>> >
>> > _______________________________________________
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>> >
>>
>>
>>
>> --
>> 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
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>
>
>
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