Radius Search

[momo]

Can anyone help me? I am writing an ASP.NET app. and I need to be able to
have people search based on X radius of a zip code. Please help.

Thanks,

Momo

[George Durzi]

Re: Radius Search

Crap! I did this a few years ago but don't have the code anymore ... But
here's the idea, you're gonna have to hunt down and find the stuff though.

I got a hold of a database of every US zip code geocoded. So every zip code
had a Lat and a Long.

There's a simple formula to measure the distance (as the crow flies) between
two co-ordinates on the earth. The original formula is complex because it
takes into account the curvature of the earth, but in it's simplified form,
it gives good results with a very acceptable (small) margin of error.

Let's use the example of car dealerships, you have a table of them, with a
zip code for each.

Since you have your search zip code, you can lookup its Lat and Long, and
perform a search of all "car dealerships" within x miles of your search zip
code.

Having the formula and the zip code geocode table makes this a piece of
cake. sorry I can't find them :(

"momo" <searchengine@s eeourweb.com> wrote in message
news:uUbpYn8nDH A.3288@tk2msftn gp13.phx.gbl...[color=blue]
> Can anyone help me? I am writing an ASP.NET app. and I need to be able to
> have people search based on X radius of a zip code. Please help.
>
> Thanks,
>
> Momo
>
>[/color]

[George Durzi]

Re: Radius Search

http://www.dbforums.com/archives/t284762.html

"George Durzi" <gdurzi@hotmail .com> wrote in message
news:urRRYt8nDH A.644@TK2MSFTNG P11.phx.gbl...[color=blue]
> Crap! I did this a few years ago but don't have the code anymore ... But
> here's the idea, you're gonna have to hunt down and find the stuff though.
>
> I got a hold of a database of every US zip code geocoded. So every zip[/color]
code[color=blue]
> had a Lat and a Long.
>
> There's a simple formula to measure the distance (as the crow flies)[/color]
between[color=blue]
> two co-ordinates on the earth. The original formula is complex because it
> takes into account the curvature of the earth, but in it's simplified[/color]
form,[color=blue]
> it gives good results with a very acceptable (small) margin of error.
>
> Let's use the example of car dealerships, you have a table of them, with a
> zip code for each.
>
> Since you have your search zip code, you can lookup its Lat and Long, and
> perform a search of all "car dealerships" within x miles of your search[/color]
zip[color=blue]
> code.
>
> Having the formula and the zip code geocode table makes this a piece of
> cake. sorry I can't find them :(
>
> "momo" <searchengine@s eeourweb.com> wrote in message
> news:uUbpYn8nDH A.3288@tk2msftn gp13.phx.gbl...[color=green]
> > Can anyone help me? I am writing an ASP.NET app. and I need to be able[/color][/color]
to[color=blue][color=green]
> > have people search based on X radius of a zip code. Please help.
> >
> > Thanks,
> >
> > Momo
> >
> >[/color]
>
>[/color]

[George Durzi]

Re: Radius Search

http://www.zipcodedownload.com/productDetails.aspx?ID=DLLDistance

http://www.zipcodedownload.com/Resources/SampleInfo/DLLDistance.dotnet-c.txt

Hope this helps.


"George Durzi" <gdurzi@hotmail .com> wrote in message
news:urRRYt8nDH A.644@TK2MSFTNG P11.phx.gbl...[color=blue]
> Crap! I did this a few years ago but don't have the code anymore ... But
> here's the idea, you're gonna have to hunt down and find the stuff though.
>
> I got a hold of a database of every US zip code geocoded. So every zip[/color]
code[color=blue]
> had a Lat and a Long.
>
> There's a simple formula to measure the distance (as the crow flies)[/color]
between[color=blue]
> two co-ordinates on the earth. The original formula is complex because it
> takes into account the curvature of the earth, but in it's simplified[/color]
form,[color=blue]
> it gives good results with a very acceptable (small) margin of error.
>
> Let's use the example of car dealerships, you have a table of them, with a
> zip code for each.
>
> Since you have your search zip code, you can lookup its Lat and Long, and
> perform a search of all "car dealerships" within x miles of your search[/color]
zip[color=blue]
> code.
>
> Having the formula and the zip code geocode table makes this a piece of
> cake. sorry I can't find them :(
>
> "momo" <searchengine@s eeourweb.com> wrote in message
> news:uUbpYn8nDH A.3288@tk2msftn gp13.phx.gbl...[color=green]
> > Can anyone help me? I am writing an ASP.NET app. and I need to be able[/color][/color]
to[color=blue][color=green]
> > have people search based on X radius of a zip code. Please help.
> >
> > Thanks,
> >
> > Momo
> >
> >[/color]
>
>[/color]

[momo]

Re: Radius Search

Thank George this will help.

Momo


"George Durzi" <gdurzi@hotmail .com> wrote in message
news:urRRYt8nDH A.644@TK2MSFTNG P11.phx.gbl...[color=blue]
> Crap! I did this a few years ago but don't have the code anymore ... But
> here's the idea, you're gonna have to hunt down and find the stuff though.
>
> I got a hold of a database of every US zip code geocoded. So every zip[/color]
code[color=blue]
> had a Lat and a Long.
>
> There's a simple formula to measure the distance (as the crow flies)[/color]
between[color=blue]
> two co-ordinates on the earth. The original formula is complex because it
> takes into account the curvature of the earth, but in it's simplified[/color]
form,[color=blue]
> it gives good results with a very acceptable (small) margin of error.
>
> Let's use the example of car dealerships, you have a table of them, with a
> zip code for each.
>
> Since you have your search zip code, you can lookup its Lat and Long, and
> perform a search of all "car dealerships" within x miles of your search[/color]
zip[color=blue]
> code.
>
> Having the formula and the zip code geocode table makes this a piece of
> cake. sorry I can't find them :(
>
> "momo" <searchengine@s eeourweb.com> wrote in message
> news:uUbpYn8nDH A.3288@tk2msftn gp13.phx.gbl...[color=green]
> > Can anyone help me? I am writing an ASP.NET app. and I need to be able[/color][/color]
to[color=blue][color=green]
> > have people search based on X radius of a zip code. Please help.
> >
> > Thanks,
> >
> > Momo
> >
> >[/color]
>
>[/color]

[JL]

Re: Radius Search

"momo" <searchengine@s eeourweb.com> wrote in message news:<uUbpYn8nD HA.3288@tk2msft ngp13.phx.gbl>. ..[color=blue]
> Can anyone help me? I am writing an ASP.NET app. and I need to be able to
> have people search based on X radius of a zip code. Please help.
>
> Thanks,
>
> Momo[/color]

KJL Software has a free Distance DLL on the freeware page
(www.kjlsoftware.com/freeware.html). You pass a from lat/lon and a to
lat/lon and it returns the distance

HTH

JL