[GRASS-user] Vector proximity Tools.

GRASS GRASS user
1

Hey Folks,

I come back with more questions for “addressing” and geo locations issues…

Looking for a tool that can take a vector file (road segment network) and point data (FSA Centroids) to relate a road segment with the closest FSA(s). FSA’s are the first three letters of a Canadian Postal Code

SI there a tool in GRASS to check this proximity with VECTOR? Or do we have to convert to raster and then back to vector?

Here is the background

  1. using PAGC as a program that can do addressing based on blok face road segments and address ranges (http://www.pagcgeo.org/)

  2. Using the freely availbe road network file from Stats Canada (http://www.statcan.ca/english/freepub/92-500-GIE/2005001/how.htm)

  3. Since postal code position data is not freely available in Canada you can only realy work with the first three characters (for free at least), or the Forward Sorting Address (FSA)

  4. The FSA list can be found in various places, I like the one on Wikipedia, although a full QC has not been done (http://en.wikipedia.org/wiki/List_of_K_Postal_Codes_of_Canada)

  5. Geoconnections has a gazateer service that will give out a centroid based on the FSA (one at a time of course) http://www.geoconnections.org/CGDI.cfm/fuseaction/developersCorner.details/id/4517/gcs.cfm

The problem is that in the road files there may be more than one MAIN STREET. So I’d like another criteria to match against… in the states the tiger data is good for zip codes… but postal codes in canada, well, cost a lot. So I’m thinking of the following rationelle

First, I need to create a FSA centroids shape file (that will later be freely distributed) by running a list of FSA’s for a province through the gazateer.

Then here is where I think GRASS might be able to come in.

Match each roadsegment to the closest FSA centroid(s). Maybe the top three. Have this info dumped to the table. Export the new road file as a shp file and use this as reference data for PAGC. This would at least help narrow down the choices as it is unlikely to have two MAIN STREETS in one postal code.

This is just an idea… so any input or LIKE experience would be welcome info

Cheers

2

V.distance may be what you need.

Michael

Michael Barton, Professor of Anthropology
School of Human Evolution & Social Change
Center for Social Dynamics & Complexity
Arizona State University

phone: 480-965-6213
fax: 480-965-7671
www: http://www.public.asu.edu/~cmbarton

From: “Sampson, David” dsampson@NRCan.gc.ca
Date: Fri, 1 Sep 2006 15:28:42 -0400
To: grassuser@grass.itc.it
Subject: [GRASS-user] Vector proximity Tools.

Hey Folks,

I come back with more questions for “addressing” and geo locations issues…

Looking for a tool that can take a vector file (road segment network) and point data (FSA Centroids) to relate a road segment with the closest FSA(s). FSA’s are the first three letters of a Canadian Postal Code

SI there a tool in GRASS to check this proximity with VECTOR? Or do we have to convert to raster and then back to vector?

Here is the background

  1. using PAGC as a program that can do addressing based on blok face road segments and address ranges (http://www.pagcgeo.org/ http://www.pagcgeo.org/ )

  2. Using the freely availbe road network file from Stats Canada (http://www.statcan.ca/english/freepub/92-500-GIE/2005001/how.htm http://www.statcan.ca/english/freepub/92-500-GIE/2005001/how.htm )

  3. Since postal code position data is not freely available in Canada you can only realy work with the first three characters (for free at least), or the Forward Sorting Address (FSA)

  4. The FSA list can be found in various places, I like the one on Wikipedia, although a full QC has not been done (http://en.wikipedia.org/wiki/List_of_K_Postal_Codes_of_Canada http://en.wikipedia.org/wiki/List_of_K_Postal_Codes_of_Canada )

  5. Geoconnections has a gazateer service that will give out a centroid based on the FSA (one at a time of course) http://www.geoconnections.org/CGDI.cfm/fuseaction/developersCorner.details/id/4517/gcs.cfm http://www.geoconnections.org/CGDI.cfm/fuseaction/developersCorner.details/id/4517/gcs.cfm

The problem is that in the road files there may be more than one MAIN STREET. So I’d like another criteria to match against… in the states the tiger data is good for zip codes… but postal codes in canada, well, cost a lot. So I’m thinking of the following rationelle

First, I need to create a FSA centroids shape file (that will later be freely distributed) by running a list of FSA’s for a province through the gazateer.

Then here is where I think GRASS might be able to come in.

Match each roadsegment to the closest FSA centroid(s). Maybe the top three. Have this info dumped to the table. Export the new road file as a shp file and use this as reference data for PAGC. This would at least help narrow down the choices as it is unlikely to have two MAIN STREETS in one postal code.

This is just an idea… so any input or LIKE experience would be welcome info

Cheers