----------------------------Original message---------------------------- <start> The "Archive of Census Related Products", located at ftp ftp.ciesin.org cd /pub/census contains a few improvements ... o Based on user requests, we have created thinned COUNTY and STATE files for the CONTIGUOUS US. These thinned files are a simple concatenation of the county files for the 49 contiguous USA states. Thinning the files has been done in 3 steps, reducing polygon points by 50% in each step. These "thinning levels" are indicated by the "thx" filename, where x gets assigned a value 1,2 or 3, indicating increasing thinning levels. (The filename designation "00" indicates US contiguous area, instead of FIPS codes). /pub/census/usa/tiger/us/original c00.zip unthinned county file s00.zip unthinned state file /pub/census/usa/tiger/us/thinned c00th1.zip thinned county file c00th2.zip thinned county file c00th3.zip thinned county file o 1% and 5% PUMAS (Public Use Microdata Sample Areas) COVERAGES. Based on a new equivalency file obtained from the Bureau of the Census ("pumgef"), we have regenerated the PUMA boundary files, This new file yields much better coverages, although problems remain, dramatically reducing the number of unchainable polygons. The coverages for 1% PUMS (bpuma) and 5% PUMS (apuma) are posted in unthinned and thinned formats. In addition we provide a file with geographic centroids for the PUMS coverages (based on UIC's genlabs macro). /pub/census/usa/tiger/us/original ap00.zip unthinned apumas ap00ctrd.zip unthinned apuma centroids apumas.not apuma failure report bp00.zip unthinned bpumas bp00ctrd.zip unthinned bpuma centroids bpumas.not bpuma failure report /pub/census/usa/tiger/us/thinned ap00th1.zip thinned apuma file ap00th2.zip thinned apuma file bp00th1.zip thinned bpuma file bp00th2.zip thinned bpuma file ap00th1.txt apuma flushing report ap00th2.txt apuma flushing report bp00th1.txt bpuma flushing report bp00th2.txt bpuma flushing report NOTE: The "[a/b]pumas.not" files indicate the problem areas we encountered. There are basically 2 main areas: LA County, CA (yet, again) and Baltimore County, MD. In addition PUMAS infrequently fail in the New England states. We are very interested to hear from local experts in the area on thoughts of fixing these errors (even a manual fix appears very doable -- please email [log in to unmask] or [log in to unmask] directly). NOTE2: When thinning, especially severely, "slivers" and areas of less than 3 points may develop. These PUMAS are flushed when writing the BNA files,please check the "[a/b]p00th[1/2/3].txt reports. <end>