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12

Since you have PostGIS 2.1.1 you're ahead of the game. Make sure you have wget installed, it is what will download the data from the Census FTP site. Create a gisdata directory with: sudo mkdir /gisdata Use chown and chgrp commands to change the ownership and group of /gisdata so that your normal user can read and write to /gisdata. Start psql and ...


8

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!


7

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 either ...


7

Very interesting question! I'd note that the geography area calculation is extremely close (in your last example, 3 msq difference over an area of 20000000 msq. (0.000015%) Since we know that census manages its data inside Oracle Spatial, I'd guess that what you're seeing is a very small difference in the implementation of geodetic area calculation between ...


7

I've spent a lot of time experimenting with this, I think it's better to post separately since they are from different angle. This is really a complex topic, see more details in my blog post about the geocoding server setup and the script I used., here is just some brief summaries: A server with only 2 States data is always faster than a server loaded with ...


6

The Short Answer: No. Census Tracts do change over time (Especially from 2000 to 2010 when in many cases they appear to be essentially redrawn). You can use the faces files to compare the same geographic area with its 2000 Census and 2010 Census assignment using dissolve techniques. You can also check out the relfiles to compare 1990 Census with 2000 Census ...


6

I don't think you want to store your ESRI Shapefiles in MongoDB. There are only two ways to store your data in MongoDB so that you might operate over them using the provided geospatial indices and queries: as GeoJSON Point, Line, or Polygon features, or as "legacy coordinate pairs." You probably want to store the same geographic features as a GeoJSON ...


6

Please check out http://www.datasciencetoolkit.org/ a ready to use virtual machine(VM) for geocoding and reverse geocoding, it provides useful information including FIPS codes. i hope it will help.


6

You've got a few options here. QGIS can natively open and process from CSV files so if your data is already in that format, you should be fine. Otherwise, you can export it to that format or install a plugin called "Spreadsheet Layers" from the Plugins Manager. There isn't really any major benefits between spreadsheet file types, just use what's simplest for ...


5

Downvote me if I'm wrong, but the GEOID is a concatenation of a bunch of fields as noted in the summary file documentation on page 13. In the geographic area codes, you'll be looking for fields at positions 26-65.


5

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 ...


5

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 ...


5

NHGIS has historical and modern census data, American Community Survey and GIS boundary files. It requires a (free) account to download data.


5

I would first assign an elevation to your road network by creating a new field in your vector data, and populating it with the desired elevation value of your roads. Then, convert it to raster using your existing DEM as the 'master raster' - ie. use the same cell size, extent, snap raster, etc. Now you have your road network in raster form, with the values ...


5

It seems that the solution lies in setting the smoothFactor argument in AddPolygons to 0, as suggested in this related post: Leaflet geojson styling leaves gaps between polygon I also found it necessary to add a small stroke to the polygons in order to completely remove the sliver gaps from the example map. leaflet() %>% addProviderTiles("CartoDB....


5

You should definitely look closer at the Mapzen Pelias geocoder. We have been having this same issue for several years, and recently discovered that one of the back-end sources for Pelias is OpenAddresses.io. You can examine the back-end data sources broken down by State and City here: https://github.com/openaddresses/openaddresses/tree/master/sources/us ...


5

Query structure: In general, querying a table for true radius lookups is best executed using ST_DWithin, i.e.: SELECT * FROM <your_table> WHERE ST_DWithin(<geom_colum>, <ref_geom>, <distance>); where <geom_column> refers to the tables geometry column, <ref_geom> the e.g. point geometry in question, and <distance> ...


4

Tiger/Line is only as good as the data submitted to it; there are commercial vendors (TomTom/TeleAtlas or Nokia/Navteq) that are much more accurate but also will cost you several thousands of dollars. For free geocoding/routing of data your good choices are highly limited.


4

You can use QGIS to work with Tiger data. It's not the newest but this video shows how to get QGIS and load Tiger: http://www.youtube.com/watch?v=EQdMTXEFtaA


4

If you turn on On the Fly Projection in the Options, that will make sure layers with different CRS's will line up correctly, assuming they have the correct CRS assigned.


4

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 = row....


4

Pasting the Cities .prj file in to http://prj2epsg.org/search gives me EPSG:3644 - NAD83(NSRS2007) / Oregon Lambert (ft) which sounds plausible. EDIT: I had to explicitly select EPSG:3644 and everything lines up for me.


4

You might like to compare your results for the area with those produced by Planimeter utility of GeographicLib. This accurately computes the area of a geodesic polygon on the reference ellipsoid. This does a direct area calculation (without an intermediate equal-area projection). It is typically accurate to better that 0.01 m^2 even for large "country ...


4

The source data is available at http://www.census.gov/geo/maps-data/data/tiger-line.html. Note that the 2000 series tab provides data in the old ASCII format, but you can get the Census tracts by US state for 2000 in shapefile format from a page off the 2010 tab. Other than that, I can only suggest contacting ESRI.


4

I must've done something wrong in following those instructions, as clearing and re-loading the data from scratch yielded a working system.


4

The documentation you are referencing (see the proposed answer below) from the Census Bureau's site refers solely to the Landview 6 product (released in 2003). The Census Bureau does not release information about specific addresses, including the exact location, due to Title 13 of the US Code. The TIGER/Line Shapefiles and the Census Geocoder documentation ...


4

It should be able to find it if postgis is in your database search path. Trying doing this: ALTER DATABASE your_db SET search_path=public,postgis; Then connect to your database again and do: CREATE EXTENSION fuzzystrmatch; CREATE EXTENSION postgis_tiger_geocoder;


4

The best way to find out what the attributes of any dataset represent and classify is to lookup the MetaData, In your case you should consult the metadata files the the US Census Bureau maintains of the TIGER dataset. Read this, the metadata files (.xml with the downloaded shapefiles) define exactly what is present in the data ...This includes MAF/TIGER ...


4

You are probably missing the District of Columbia data. Using what you have for the state of Washington, you get the "best" result, which is fairly bad (wrong town and postal code)


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