Geocode opinions

[easpengren]

I'm in the process of working out a way of geocoding using parcel shape data that I got from my local planning department. It's very nice, if very data specific, I wish I could share it. I will if anybody is interested, but it's not likely to scale to other applications.

I've dumped the parcel data into PostGIS and I'm dumping the data of people who live in the area into the same database. I plan to do a pretty simple join between the two tables (with address data) and insert the geometry data from the parcels into the people table.

Now I'm wondering, should I insert a centroid or PT_onsurface point from the parcels? Or is their a better option?

Eric Aspengren

[Josh Livni-3]

What are you trying to accomplish?  Do you need to have a duplicate
style geometry in the people table, or can you just make a join table
and get people and geometries associated more dynamically each query?  
I guess I'm confused about what your end goal is.

Of course others may not be... but just in case, can you describe your
use-case in more detail?

  -Josh



easpengren wrote:

> I'm in the process of working out a way of geocoding using parcel shape data
> that I got from my local planning department. It's very nice, if very data
> specific, I wish I could share it. I will if anybody is interested, but it's
> not likely to scale to other applications.
>
> I've dumped the parcel data into PostGIS and I'm dumping the data of people
> who live in the area into the same database. I plan to do a pretty simple
> join between the two tables (with address data) and insert the geometry data
> from the parcels into the people table.
>
> Now I'm wondering, should I insert a centroid or PT_onsurface point from the
> parcels? Or is their a better option?
>
> Eric Aspengren
>  

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[easpengren]

Unfortunately, I have a few uses for this that I'd like to accomplish.
And that likely makes this a little more complicated than it should be
(that's me in a nutshell).

That data involved is fairly large, it's a list of all the registered
voters (and their voting history, gender, Etc.) in a fairly urban county
and all of the parcels in that county, with detailed data concerning the
parcels (type of parcel, value Etc.). I'd like to be able to serve maps
with this data, I plan to use R to do some geospatial analysis with this
and routing data (in conjunction with pgrouter and road data).

I considered a simple join, and I haven't ruled that out. The issues are
speed, and in the case of analysis, accuracy. I'm pretty new to the
geospatial analysis thing, so I'm kind of going in blind with that.

Would I take a big hit in speed if I just use a join? That's why I was
more interested in inserting the parcel geom into the voter geom.

I decided to use the parcel data for the geocoding because the address
data are perfect for geocoding, and it's quite up to date.

If any of this makes sense, what would people suggest would be better,
centroid data or PT_onsurface?

If it doesn't make sense, let me know, I'll try and take a stab at a
better description.

Josh Livni wrote:

> What are you trying to accomplish?  Do you need to have a duplicate
> style geometry in the people table, or can you just make a join table
> and get people and geometries associated more dynamically each
> query?   I guess I'm confused about what your end goal is.
> Of course others may not be... but just in case, can you describe your
> use-case in more detail?
>
>  -Josh
>
>
>
> easpengren wrote:
>> I'm in the process of working out a way of geocoding using parcel
>> shape data
>> that I got from my local planning department. It's very nice, if very
>> data
>> specific, I wish I could share it. I will if anybody is interested,
>> but it's
>> not likely to scale to other applications.
>>
>> I've dumped the parcel data into PostGIS and I'm dumping the data of
>> people
>> who live in the area into the same database. I plan to do a pretty
>> simple
>> join between the two tables (with address data) and insert the
>> geometry data
>> from the parcels into the people table.
>>
>> Now I'm wondering, should I insert a centroid or PT_onsurface point
>> from the
>> parcels? Or is their a better option?
>>
>> Eric Aspengren
>>  
> _______________________________________________
> postgis-users mailing list
> postgis-users@...
> http://postgis.refractions.net/mailman/listinfo/postgis-users
>
>

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[easpengren]

Unfortunately, I have a few uses for this that I'd like to accomplish. And that likely makes this a little more complicated than it should be (that's me in a nutshell).

That data involved is fairly large, it's a list of all the registered voters (and their voting history, gender, Etc.) in a fairly urban county and all of the parcels in that county, with detailed data concerning the parcels (type of parcel, value Etc.). I'd like to be able to serve maps with this data, I plan to use R to do some geospatial analysis with this and routing data (in conjunction with pgrouter and road data).

I considered a simple join, and I haven't ruled that out. The issues are speed, and in the case of analysis, accuracy. I'm pretty new to the geospatial analysis thing, so I'm kind of going in blind with that.

Would I take a big hit in speed if I just use a join? That's why I was more interested in inserting the parcel geom into the voter geom.

I decided to use the parcel data for the geocoding because the address data are perfect for geocoding, and it's quite up to date.

If any of this makes sense, what would people suggest would be better, centroid data or PT_onsurface?

If it doesn't make sense, let me know, I'll try and take a stab at a better description.

easpengren wrote:

I'm in the process of working out a way of geocoding using parcel shape data that I got from my local planning department. It's very nice, if very data specific, I wish I could share it. I will if anybody is interested, but it's not likely to scale to other applications.

I've dumped the parcel data into PostGIS and I'm dumping the data of people who live in the area into the same database. I plan to do a pretty simple join between the two tables (with address data) and insert the geometry data from the parcels into the people table.

Now I'm wondering, should I insert a centroid or PT_onsurface point from the parcels? Or is their a better option?

Eric Aspengren

[easpengren]

I'm sorry, ST_pointonsurface. I should remember not to post when I have a cold.

easpengren wrote:

I'm in the process of working out a way of geocoding using parcel shape data that I got from my local planning department. It's very nice, if very data specific, I wish I could share it. I will if anybody is interested, but it's not likely to scale to other applications.

I've dumped the parcel data into PostGIS and I'm dumping the data of people who live in the area into the same database. I plan to do a pretty simple join between the two tables (with address data) and insert the geometry data from the parcels into the people table.

Now I'm wondering, should I insert a centroid or PT_onsurface point from the parcels? Or is their a better option?

Eric Aspengren

[bitner]

PointOnSurface() would be much better than Centroid() as a Centroid may fall outside of the polygon.

On Jan 11, 2008 10:21 PM, easpengren <phat-ass@...> wrote:

I'm sorry, ST_pointonsurface. I should remember not to post when I have a
cold.

easpengren wrote:

>
> I'm in the process of working out a way of geocoding using parcel shape
> data that I got from my local planning department. It's very nice, if very
> data specific, I wish I could share it. I will if anybody is interested,
> but it's not likely to scale to other applications.
>
> I've dumped the parcel data into PostGIS and I'm dumping the data of
> people who live in the area into the same database. I plan to do a pretty
> simple join between the two tables (with address data) and insert the
> geometry data from the parcels into the people table.
>
> Now I'm wondering, should I insert a centroid or PT_onsurface point from
> the parcels? Or is their a better option?
>
> Eric Aspengren
>

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