[postgis-users] distance between two POINTM

[Michael Welter]

Correct, but driving distance doesn't account for the 700m discrepancy.

This creates the column on the table:
select AddGeometryColumn('','point','geom',4269,'POINTM',3);

This adds the point to the table:
insert into point (handsetid,ts,geom) values (1,'2007-05-11 
11:01',GeomFromEWKT('SRID=4269;POINTM(-105.32395 39.50163 2563)'));
insert into point (handsetid,ts,geom) values (1,'2007-05-11 
11:02',GeomFromEWKT('SRID=4269;POINTM(-105.30166 39.53806 2487)'));

This retrieves the points from the table:
select asEWKT(geom)  from handsetpoint;
                    asewkt
--------------------------------------------
  SRID=4269;POINTM(-105.32395 39.50163 2563)
  SRID=4269;POINTM(-105.30166 39.53806 2487)



Thanks,




Michael Fuhr wrote:
> On Sun, May 13, 2007 at 03:04:39PM -0600, Michael Welter wrote:
>> select distance_sphere(GeomFromEWKT('SRID=4269;POINTM(-105.32395 
>> 39.50163 2563)'),GeomFromEWKT('SRID=4269;POINTM(-105.30166 39.53806 
>> 2487)'));
> 
> These points appear to be along US285 in the vicinity of Conifer, CO.
> Might your GPS be measuring driving distance instead of straight-line
> distance?
> 

-- 
Michael Welter
Telecom Matters Corp.
Denver, Colorado US
+1.303.414.4980
mike at TelecomMatters.net
www.TelecomMatters.net