[postgis-users] Odd question

Paragon Corporation lr at pcorp.us
Sun Sep 16 21:35:16 PDT 2012


The offset is to get you on the right side of the street, not to compensate
for the fuzzyness of census data.
 
Not sure if that was clear.  The census data are all street centerlines, and
what the offset is intended to do is this
Say your road looks like this:
 
0       24          30
-----------------------------------
1       25        31
 
Say lets say your street address is like 25 State street, the interpolation
would put you on the centerline of the line corresponding to 24/25
 
But since we know you are 25 -- the 10 offset pushes the point to hit the 25
(so 10 meters) in the 25 direction
 
So the offset should be more accurate than without as it would put you on
the correct side of the road instead of standing in the middle of it.


  _____  

From: postgis-users-bounces at postgis.refractions.net
[mailto:postgis-users-bounces at postgis.refractions.net] On Behalf Of Chris
English
Sent: Sunday, September 16, 2012 9:14 AM
To: postgis_users
Subject: Re: [postgis-users] Odd question


But changing the setting to zero doesn't get one necessarily closer to the 
true location of the address, does it?  It remains fuzzy as was the intent
of the census bureau to elide.
Chris


  _____  

Date: Sat, 15 Sep 2012 18:46:06 -0500
From: ericaspen at gmail.com
To: postgis-users at postgis.refractions.net
Subject: Re: [postgis-users] Odd question

That's fantastic! Exactly what I was looking for. Thank you very much.


On Sat, Sep 15, 2012 at 6:44 PM, Paragon Corporation <lr at pcorp.us> wrote:


Eric,

Did y ou want to change the default or set it to 0 or something?

We were meaning to expose that but wasn't sure if anyone would be interested
in changing it.

The setting is on the function:

interpolate_from_address

Just change the hardcoded default of 10 to what you want.



CREATE OR REPLACE FUNCTION interpolate_from_address(given_address INTEGER,
in_addr1 VARCHAR, in_addr2 VARCHAR, in_road GEOMETRY,
        in_side VARCHAR DEFAULT '',in_offset_m float DEFAULT 10 );


In 2.1. we'll add to the list to allow this to be voerrided at the geocode
function level as an additional arg.  Can't do that with the 2.0 one though
since that would change the api.

Hope that helps,
Regina
http://www.postgis.us




-----Original Message-----
From: postgis-users-bounces at postgis.refractions.net
[mailto:postgis-users-bounces at postgis.refractions.net] On Behalf Of Eric
Aspengren
Sent: Saturday, September 15, 2012 5:20 PM
To: PostGIS Users Discussion
Subject: [postgis-users] Odd question

Anybody know how to remove the default 10 meter offset from the PostGIS
geocoder?


--
Eric Aspengren
(402) 478-8683
www.streetlevelstrategies.com
ericaspen at gmail.com




_______________________________________________
postgis-users mailing list
postgis-users at postgis.refractions.net
http://postgis.refractions.net/mailman/listinfo/postgis-users





-- 
Eric Aspengren
(402) 478-8683
www.streetlevelstrategies.com
ericaspen at gmail.com

_______________________________________________ postgis-users mailing list
postgis-users at postgis.refractions.net
http://postgis.refractions.net/mailman/listinfo/postgis-users
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/postgis-users/attachments/20120917/12693108/attachment.html>


More information about the postgis-users mailing list