Re: Zip codes and Electoral districts

Posted by Frank Warmerdam on Feb 09, 2007; 4:53am
URL: http://civicaccess.416.s1.nabble.com/Zip-codes-and-Electoral-districts-tp865p866.html

Stéphane Zagar wrote:
> Hey
>
> In fact, technically it's not complicated to get a zip code mapping with
> latitude and longitude :
>
> H3T1A1;45.5113;-73.6162
...

> H3T1Z1;45.4977;-73.6257
>
> And I think it's not that much complicated to do the same reverse
> engineering for electoral district.
>
> The problem is that mathematically, there are about 17 millions of valid
> combination of zip code. It take about 1 sec for my script to retrieve
> the zipcode/lat-long so if we do a basic computation it gives us
> about... 100 days to retrieve everything (and probably a lot of
> bandwidth). Even if we set the last number to 1 (what I did in my
> previous test), it's still about 2 millions valid values. And I'm not
> sure if the website I use to retrieve this will allow this (with 1
> request/sec, I can't imagine they won't see that something is happening).

Stéphane,

I'm afraid I haven't been following this thread very closely despite the
fact that it is close to my heart.  But I'd assume the terms of use for
the site do not allow you to extract their full database this way and
redistribute it.  Is that not the case?

> By the way, I have a question for geostuff people (Tracey ?) : On the
> geogratis website, there are some files concerning the electoral
> districts (
> http://geogratis.cgdi.gc.ca/geogratis/en/option/select.do?id=1169), but
> I don't know anything concerning the format (Arc Export or shape file).
> Is there a way to do something with that ? For example do a process
> what-ever to find out in which electoral district is a point (long-lat) ?

I can definitely help with this sort of thing if you want to do it.
Geo-data-wrangling is my thing.

Best regards,
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