Hot answers tagged tiger
9
I haven't had a chance to test out the Nominatim and Geocoder US geocoders. My understanding though is that the Geocoder and Nominatim can't be run directly in the database, which to me is a big disadvantage because it makes them difficult to use in things like triggers or for batch updates directly in the database.
PostGIS geocoder being a pure ...
9
You have to change the Coordinate Reference System of the project; QGIS won't do that when you load a shape file.
Go to: settings->Project Properties->Coordinate Reference System (CRS) and search for your projection.
Although WGS84 and NAD83 both refer to datums not projections. If you want to project your TIGER data, I would be inclined to use either a ...
7
You can download Census Blocks from TIGER; you'll just have to download the data on a state-by-state basis and merge it all together.
EDIT: See this page for block-level shapefiles that already have the population and housing unit counts attached, so you don't have to deal with joining SF1 tables!
5
You have two ways of reducing the file size:
Remove all the pretty formatting and redundant white space. In some 'XML-style' files this can be a surprisingly large amount and can easily double or even treble your file size. However I doubt it accounts for the difference in your volume and the data you link to above.
Reduce the volume of actual data ...
5
The official file is not currently available as of 5-12-2011, but should be sometime this summer.
My team might create our own version for use in the interim. If we do, I will post back a download link here.
We put in an official query to the geo.geography at census.gov team and got an (impressively) fast answer. Below is their response.
We do not ...
5
You need the tables
addr,
addrfn,
and featnames.
And the geography in the edges layers.
addr
These are address ranges, just address ranges. They relate to feature (i.e. road) names via...
addrfn
A table relating address ranges and feature names. addr.ARID -> addrfn -> featnames.LINEARID
featnames
A table of feature names. Each edge (line) can have ...
4
For just the state boundaries, you can download data from data.gov. If you're interested in the actual OSM data, you can download it at cloudmade, but it takes some processing to work with and is a fairly complex dataset.
4
PLACEFP10 references an incorporated place (city, town) or Census Designated Place (CDP). COUSUBFP10 refers to a county subdivision. This can include incorporated places but not CDPs. There will "always" be an associated county subdivision but not necessarily a place. County subdivisions are frequently townships but it varies state to state.
If PLACEFP10 is ...
3
If you need a gridded data set CIESIN's Gridded Population datasets may be of use. See http://sedac.ciesin.columbia.edu/gpw/aboutus.jsp#aboutTable for more details. The best resolution is 30 Arc seconds.
3
I have been using the 2010 TIGER shapefiles extensively and found the transition easy. The basic change is that what used to be separated into different shapefiles is now contained in a single one: rivers, roads, special places, railroads, everything. The [MTFCC] field tells you what's what. All the roads have an "S" prefix; e.g., S1100 is primary roads. ...
3
I have spent a lot of time mapping block groups and found that rendering them as tiles is usually the most efficient option.
Client Side Flash Rendering: Max = Counties
The most detailed geography you can reasonably expect a client browser to render on a national scale is US Counties and even those require significant optimization. The NY Times has a ...
2
The ogr2ogr utility of OGR will do the trick, here's an example adapted from the FAQ:
# loop through all of the shapefiles in the directory and load them
for i in $(ls *.shp); do
ogr2ogr -f 'ESRI Shapefile' -a_srs "EPSG:4269" -nln merged_tiger_roads $i -update -append -skipfailures
done
This should produce a single merged_tiger_roads.shp from the ...
2
There are tools for uploading tiger data to PostGIS. It might be a little easier to work with once it's in PostGIS. Here are some links:
http://pylab.blogspot.com/2007/02/import-tiger-database-to-postgis.html
http://geoserver.org/display/GEOSDOC/Loading+TIGER+polygons+tigerpoly.pl
Here's a ruby script for parsing Tiger data:
...
2
Isn't this as simple as your database storing coordinate pairs in the format of x y and not lat lon (which would be y x).
If the db used the format of lat lon, how would it handle other coordinate systems?
If you look at the MySQL docs, it appears that the point class has an x property and a y property. ...
2
The Data is not quite there for what you require - but some is...
The TIGER Edited Map maybe of interest to you.
http://wiki.openstreetmap.org/wiki/TIGER_Edited_Map
Red areas are ways which have not been edited since the TIGER import.
Green areas are ways which have been edited.
There still is quite a large amount of fix up required for the TIGER ...
2
If you are looking for other geocoding data sources, you would probably benefit by searching and reading previous discussions on this site (with the tag [geocoding]), but a couple specifics I would recommed reading are:
Geocode quality: Nominatim vs. PostGIS Geocoder vs. Geocoder::US 2.0
Is there an open source Geocoding tool which can be used ...
2
Here is a bit of totally untested code that might work for you:
import arcpy
feat1 = 'finished_feature_class'
feat2 = 'spatially_joined_feature_class'
with arcpy.SearchCursor(feat2,['name_of_place_field','name_of_county_field']) as cursor:
# create a dictionary to hold our place/county data
places = {}
for row in cursor:
place = ...
2
Use an FTP client (e.g. FileZilla), which will allow you to download multiple files at once. After installing and starting your FTP client software:
Connect to ftp2.census.gov
username = anonymous
password = your email address
Navigate to the folder where you want to save files on your local system
Navigate to the geo/tiger/TIGER2012/EDGES directory (or ...
1
I've done what you're attempting with the Tiger road data, so it stands to reason it would work for what you're doing here. The bold value in this filename (the last one in your list, above)..
tl_2012_04005_edges.zip
..is a so-called FIPS code. Specifically, this one is Coconino County, AZ. So all you need is something that provides a nice list of FIPS ...
1
Actually, ogr2ogr does not decide, it is up to the user to choose a suitable proj string.
For NAD1983, the datum shift to WGS84 is 0, that is both use the same ellipsoid in the same position. Proj string would be:
+proj=longlat +ellps=GRS80 +towgs84=0,0,0,0,0,0,0 +no_defs
or s_srs EPSG:4269 t_srs EPSG:4326
Your data is in degrees, so no transformation ...
1
I realize this is an old question, and you may have an answer.
The problem is that ZIP codes are defined by the Postal Service and change constantly. Also, Census wants geographies to be continuous, integral, and comprehensive; the ZIP code is none of these. At its heart, it is a list of addresses and not an "area." Census does realize, however, that many ...
1
Yes, choose State Legislative Districts as the layer type. You will then be able to download separate shapefiles for the Illinois Upper and Lower Chambers for 2000 & 2010.
These shapefiles do NOT include details about particular politicians, as these boundaries only change during redistricting and therefore each district is often represented by multiple ...
1
I had the same problem. Almost drove me crazy - documentation is a bit scarce and I started to look in the sources.
Turned out to be a bug in the mapnik library (installed from some Ubuntu PPA). After cloning the git repository and building everything from source, it is working fine now.
Note that the UTFGrid spec has provisions to avoid the character ...
1
Glenn:
oneway = 'yes' is how I understand flow direction limitations in OSM.
OSM shares nodes on intersecting ways. You can detect the ways by checking the reference ids of the nodes.
I have noticed that there are more than a few shared nodes at grade separated crossings which can cause some pretty serious routing issues.
Since much of OSM in the US ...
1
2007 Census data in Google Maps API - Age
http://mapperz.brinkster.net/Drive_Time/index.html
[ignore/ok the 'error' message from the hosting site]
Using
Google Maps API (v2) can be v3 now
Google Charts API
& backend
http://sampleserver1.arcgisonline.com/ArcGIS/rest/services/Demographics/ESRI_Census_USA/
...
1
I'd look at loading the data in to PostGIS and then running GeoServer to provide a WMS layer that you can overlay above Google Maps using OpenLayers. If you find you need more speed later you can add a tile cache between GeoServer and OpenLayers.
1
Matlab has a function to read in shapefiles. Census data is in a geographic projection which is not terribly useful for distance calculations. You may want to use OGR to project it to a suitable coordinate system, first.
Only top voted, non community-wiki answers of a minimum length are eligible
