Thanks Steve, then I hope ST_Length on the spheroid will be suitable for my purpose.
Thanks, Raghavan On Mon, Apr 21, 2014 at 11:07 AM, Stephen Woodbridge < [email protected]> wrote: > On 4/21/2014 11:25 AM, Raghavan Krishnasamylakshmanaperumal wrote: > >> Hi All, >> >> I am trying to make use of linestring's length for one of my route >> detection experiment. >> >> My linestring data is in this format >> "the_geom geometry(LineString,4326)" >> >> I tried using ST_Length(the_geom), ST_Length(the_geom,true) and the >> results are as follows, >> >> */the_geom geometry(LineString,4326)/* >> "0102000020E6100000030000008204C58F31C551C070AC8BDB682C4540DA >> 1B7C6132C551C0BF7D1D38672C45403333333333C551C00D4FAF94652C4540" >> >> /*ST_Length(the_geom) >> */0.000141421356226931 >> >> *ST_Length(the_geom,true) *i.e spheroid=true >> >> 13.8305487635736 >> >> >> >> What is the metric used for these st_length values? Also if I want to >> use length as my edge cost in a graph formed out of these linestrings >> which length function I should use? >> > > ST_Length() returns the distance is the object units. In 4326 this would > be degrees > > ST_Length on the spheriod is probably in meters. > > -Steve > > _______________________________________________ > postgis-users mailing list > [email protected] > http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users >
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