Dear Dan, In the Word document (KUMC_census_acs_documentation.docx) available at this link <https://drive.google.com/folderview?id=0B_ChrVjKL2WYMXE3azlGYm54Zkk&usp=sharing>, I included the fields that are required to uniquely identify census units in the various .dat files. They are listed on pages 5 and 6.
Block groups are uniquely identified by concatenating STATE, COUNTY, TRACT, and BLKGRP. Census tracts are uniquely identified by concatenating STATE, COUNTY, and TRACT. On the kumc_geocoded.txt you will want to do the following concatenations for tract and block group: FIPSSTCO + TRACT_ID = census tract FIPSSTCO + TRACT_ID + first character of the BLOCK_ID (left most character) = block group FIPSTCO + TRACT_ID + BLOCK_ID = census block Do you also have access to a zip archive called block_crosswalk.zip? It should have been provided to each site from Justin Dale. That ZIP archive contains a crosswalk that links census blocks to a large number of other census identifiers. You can use the crosswalk to link census identifiers to the geocoded data on the census block. Yours, Dave On Mon, Jan 9, 2017 at 2:38 PM, Dan Connolly <dconno...@kumc.edu> wrote: > Hi Dave, > > More questions! > > I'm copying gpc-dev so we can all learn together. Before you reply all, > note the public archive http://listserv.kumc.edu/pipermail/gpc-dev/ > > I'm working with Maren and Sravani on this stuff. Joining on zip code was > straightforward: we used the zcta5 column of acs_20135a/*zcta_860*/ge.00_ > file.dat.gz. > > But now we're trying to join on tract and census block. What columns of > acs_20135a/*blck_grp_150*/ge.00_file.dat.gz and acs_20135a/*tract_140* > /ge.00_file.dat.gz should we use? What are their primary key columns? > Which documentation would tell us this? > > BLKGRP looks like a single-digit number; it's clearly not a unique key to > the blck_grp_150 data. > > TRACT is a bigger number, but it's not a unique key to *tract_140* > either. It seems to be unique within state, though. Is that right? Should > we join TRACT_ID and ST_ABRV from geocoded_kumc.txt with TRACT and STUSAB > of tract_140? > > Have any other GPC sites figured this out yet? MU? UTHSCSA? > > For reference, these are the columns of our kumc_geocoded.txt data: > > 'OID,Join_Count,TARGET_FID,Loc_name,Status,Score,Match_type,' > 'X,Y,Match_addr,DISP_LON,DISP_LAT,SIDE,' > 'ARC_Address,ARC_City,ARC_State,' > 'ARC_Zip,ADDRESS,CITY,STATE,ZIP,New_X,New_Y,ID,BLOCK_ID,' > 'FIPSST,FIPSCO,FIPSSTCO,TRACT_ID,ST_ABRV,CO_NAME,ST_NAME > > context: > https://informatics.gpcnetwork.org/trac/Project/ticket/140 > https://informatics.gpcnetwork.org/trac/Project/ticket/350 > > -- > Dan > > -- David Van Riper Spatial Analysis Core Director Minnesota Population Center University of Minnesota Email: vanri...@umn.edu Phone: 612-625-7375
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