Re: [postgis-users] PG Routing

[Maria Arias de Reyna]

El Domingo 03 Julio 2011, James David Smith escribió:
> Dear all,
> 
> I have a table of GPS points which are the locations of vehicles every
> 15 seconds. Each journey that a car makes has an ID. For example a
> taxi is on 'job 1' and has 50 points while it does this job, and then
> another 50 or 60 when it is on 'job 2' etc. What I would like to do
> however is investigate whether the car took the most effecient route
> between the two points. To this end I think that I can use the
> PGROUTING extension of PostGIS...?  Does this sound possible?

You can calculate the shortest path with pgRouting and then compare it with 
the length of the linestring formed with this GPS points. Probably you will 
have a longer path with the GPS points (because the GPS is never exact) but if 
you add a percent of error to the shortest path calculated by pgRouting you 
will know if the vehicle did a good or a bad path.

> I have
> found the PGROUTING website, and download the ZIP file for Windows
> installation, however I am not sure how to install it. Could somebody
> please tell me how or provide a link to a good place to read about how
> to install and use PGROUTING? 

Why are you using Windows (for any serious work)? There is a PPA for Ubuntu[1] 
which has a direct install while pgRouting binaries for Windows are old and 
strongly dependent of a postgresql version. And remember that you must install 
postgis first.

Anyway, if you are thinking of having a real-time server with several vehicles 
sending positions every 15 seconds, forget Windows. It will be insane. If it 
is insane if you do it on a non-strongly-optimized database on Linux I don't 
want to know how hard it will be on Windows. Believe me, I have made a few of 
this real-time systems.


[1]https://launchpad.net/~georepublic/+archive/pgrouting
-- 
María Arias de Reyna Domínguez
Área de Operaciones

Emergya Consultoría 
Tfno: +34 954 51 75 77 / +34 607 43 74 27
Fax: +34 954 51 64 73 
www.emergya.es 
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Re: [postgis-users] PostGIS 2.0 installation error

[Denis Rykov]

I'm using "PostgreSQL 9.0.4 on i686-pc-linux-gnu, compiled by GCC
gcc-4.5.real (Ubuntu/Linaro 4.5.2-8ubuntu4) 4.5.2, 32-bit"

On Mon, Jul 4, 2011 at 2:20 AM, Mark Cave-Ayland <
mark.cave-ayl...@siriusit.co.uk> wrote:

> On 03/07/11 16:41, Denis Rykov wrote:
>
>  |ERROR:  could not load library"/usr/lib/postgresql/9.**0/lib/
>> postgis-2.0.so  ": /usr/lib/postgresql/9.0/lib/po*
>> *stgis-2.0.so   : undefined
>> symbol: DirectFunctionCall3Coll
>>
>>
>> |
>>
>> More detailed information at :
>> http://gis.stackexchange.com/**questions/11759/postgis-**
>> installation-error
>>
>
> That's a strange error - it almost implies that a PostgreSQL 9.0-only macro
> has been used somewhere in the source code. Which version of PostgreSQL are
> you building against?
>
>
> ATB,
>
> Mark.
>
> --
> Mark Cave-Ayland - Senior Technical Architect
> PostgreSQL - PostGIS
> Sirius Corporation plc - control through freedom
> http://www.siriusit.co.uk
> t: +44 870 608 0063
>
> Sirius Labs: http://www.siriusit.co.uk/labs
> __**_
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Re: [postgis-users] PostGIS 2.0 installation error

[Mark Cave-Ayland]

On 03/07/11 16:41, Denis Rykov wrote:


|ERROR:  could not load library"/usr/lib/postgresql/9.0/lib/postgis-2.0.so  
": /usr/lib/postgresql/9.0/lib/postgis-2.0.so  
: undefined symbol: DirectFunctionCall3Coll

|

More detailed information at :
http://gis.stackexchange.com/questions/11759/postgis-installation-error


That's a strange error - it almost implies that a PostgreSQL 9.0-only 
macro has been used somewhere in the source code. Which version of 
PostgreSQL are you building against?



ATB,

Mark.

--
Mark Cave-Ayland - Senior Technical Architect
PostgreSQL - PostGIS
Sirius Corporation plc - control through freedom
http://www.siriusit.co.uk
t: +44 870 608 0063

Sirius Labs: http://www.siriusit.co.uk/labs
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[postgis-users] minimum value of the query result

[Brian Sanjeewa Rupasinghe]

Hi,

I retreive minimum x of each bounding box of some polygons using following
query:

SELECT (min(ST_XMin(BOX2D((ST_Dump(the_geom)).geom as XMin
from building_poly;

How can i find the minimum X of all Xmin coordinatges? Can i use min()?


Cheers, Sanjeewa.
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[postgis-users] PG Routing

[James David Smith]

Dear all,

I have a table of GPS points which are the locations of vehicles every
15 seconds. Each journey that a car makes has an ID. For example a
taxi is on 'job 1' and has 50 points while it does this job, and then
another 50 or 60 when it is on 'job 2' etc. What I would like to do
however is investigate whether the car took the most effecient route
between the two points. To this end I think that I can use the
PGROUTING extension of PostGIS...?  Does this sound possible? I have
found the PGROUTING website, and download the ZIP file for Windows
installation, however I am not sure how to install it. Could somebody
please tell me how or provide a link to a good place to read about how
to install and use PGROUTING?  Alternatively, is there a better way of
accomplosing my task?

Best wishes

James
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[postgis-users] PostGIS 2.0 installation error

[Denis Rykov]

ERROR:  could not load library
"/usr/lib/postgresql/9.0/lib/postgis-2.0.so":
/usr/lib/postgresql/9.0/lib/postgis-2.0.so: undefined symbol:
DirectFunctionCall3Coll

More detailed information at :
http://gis.stackexchange.com/questions/11759/postgis-installation-error
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