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Here are a number of tips to ease the process of using the Census 2000 data.
The RS/6000 Cluster and Nicco have copies of the California SF1 data files that you can use. On the RS/6000 Cluster the data files are in a directory called /u/datalib01/cusgdbl/census2000/sf1/ and on Nicco they are in a directory called /home2/census . Instead of FTP'ing the data from other locations, you can access these data files from the RS/6000 Cluster or from Nicco.
You can use FTP from within UNIX to get the SF1 data files. The data files for California are stored locally on the RS/6000 Cluster and on Nicco, but you might be using a different UNIX system or you might want to get data files for a different state. Here is an example session showing how to get az0005.uf1.zip for Arizona. What you type is shown in bold. Be patient when downloading the files... it can take over 30 minutes to download a file, and there is no feedback as to the progress being made. You will simply see a message when the transfer is complete.
% ftp www2.census.gov Connected to ftp2.census.gov. 220-You have accessed ftp.census.gov a Government computer! 220- 220 ftp2.census.gov FTP server (Version wu-2.6.1(1) Tue Aug 15 13:01:18 EDT 2000) ready. Name (www2.census.gov:mnm): anonymous 331 Guest login ok, send your complete e-mail address as password. Password: joebruin@ucla.edu 230 Guest login ok, access restrictions apply. ftp> cd census_2000 250 CWD command successful. ftp> cd datasets 250-These datasets are flat ASCII files. Spreadsheet/database software is 250-needed to generate tables. For prepared tables from these data, see 250-factfinder.census.gov. 250- 250- 250 CWD command successful. ftp> cd Summary_File_1 250 CWD command successful. ftp> cd Arizona 250 CWD command successful. ftp> binary 200 Type set to I. ftp> get az00005_uf1.zip 200 PORT command successful. 150 Opening BINARY mode data connection for az00005_uf1.zip (28938305 bytes).
Note that you must issue the binary command to get a binary transfer, otherwise the file will be useless. Also, note that what you type is case sensitive. You must type cd Summary_File_1 and not cd summary_file_1 . You can also use the ls command to view the files contained in a directory. If you wish to get multiple files with wildcards, you can use the prompt command and then use mget, for example below we get all 40 of the files.
ftp> prompt Interactive mode off. ftp> mget *.zip 200 PORT command successful. 150 Opening BINARY mode data connection for az00001_uf1.zip (23468338 bytes). <rest of the output is omitted to save space>
On UNIX, we would recommend using SAS to read the compressed file on the fly without decompressing it first. This is the fastest way to read the files and uses the least disk space. However, if you are using another program (like SPSS or Stata) then you will need to first decompress the file before you can use it.
If you have a .zip file, then you can decompress it with the unzip command, for example
unzip -a ca00005_uf1.zip
If you have a .gz file, then you can decompress it with gunzip, for example
gunzip -a ca00005_uf1.zip
or if you are using the RS/6000 Cluster,
gunzip.q -a ca00005_uf1.zip
On Windows, we would recommend using SAS to read the compressed file on the fly without decompressing it first. This is the fastest way to read the files and uses the least disk space. However, if you are using another program (like SPSS or Stata) then you will need to first decompress the file before you can use it. You can use winzip to decompress both .zip files and .gz files.
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