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| GeoCommunity Mailing List |
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| Mailing List Archives |
| Subject: | Re: GISList: Problem using US Census 2000 Data |
| Date: |
09/06/2001 03:52:17 PM |
| From: |
David.L.Williams .. us.mwhglobal.com |
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Attached below are some of the useful summaries that I received regarding
working with the Census 2000 Summary File 1 (SF1) and polygons from the
Census redistricting shapefiles. I have yet to choose a method of attack
and would look forward to other responses on the best method.
Cheers
Dave
My original email:
Has anyone began working with the Census 2000 Summary File 1 (SF1) and
joined it to block polygons from the Census redistricting shapefiles? I
have purchased the SF1 CD from the Census Bureau and have not been able to
find a quick reference to sorting out this task. The database includes 39
tables with 8700+ columns and little reference to where to begin. I would
appreciate any responses and will sum.
1)
I receive a similar CD from the Census with 1980 data and found the
following website useful in sorting out the data..
No promises but it may help.
http://tier2.census.gov/crlf.htm
Good Luck
Josh DeBruyn, Project Planner
Gove Associates Inc.
1601 Portage Rd.
Kalamazoo, MI 49001
DID Voice (616) 373-7513
Toll Free 1-800-632-5753
Fax (616) 382-6972
2)
You need to make sure you have the SFgeo table merged with your tables,
then create tables by summary level. Then you can create the block name
to look identical to the polygon id field. The census bureau site has
lots of helpful information and a data dictionary you can download as well.
Matthew
3)
I've taken SF1 and put it into a SQL database. This was done by setting
a relation to the state abbreviation and logical record number
{logrecno} in the geography file and the different table segments. I am
then able to create dbf files from the SQL database for use in ArcView.
Working with SF1 is difficult. I had to print the entire documentation
(several hundred pages) and refer to it often in order extract the
different data fields as clients request them. The documentation is a
necessity - so is a knowledge of a good database application (foxpro or
sql server).
I downloaded the files from the Bureaus web site: I'm not sure if they
come in a different for when purchased on a CD. If they are flat ASCI
files you will need to begin by creating a dbf file structure to append
the ASCI files into.
Just some random thoughts - Hope this helps.
Joel Wilson
Election Data Services
(202) 789-2004
4)
Yes - I've been working with these files since they became available and
I'm also dealing with the same problems. But PL94 & SF-1 tables can be
linked via the logrecno. This number is unique within each state. I'm sure
you know this.
For the joining function, check the bureau's website for a downlaodable
table that links 90 to 2000 geographic. They are in the tiger area. The
bureau put out three tables a few week back. I found it the other week and
I'm using it. They work, but it's not 100%. We have 90 blocks that are now
several 2000 blocks. These tables, put a "P" in one of the columns
indicating that a percentage is in two or more blocks. They do not give you
the percentage, they are just tell you what one block in 90 is now three
blocks in 2000.
These tables are similar to the geo table that comes with the PL94-171
data. But been reworker to help????
I'm hoping this helps. If you find out more information please include me
in your e-mails.
Dennis Moody
Information Technology Agency
200 N Main St - 1400 CHE
Los Angeles, Ca. 90012
5)
All of this work has already been done, so don't waste your time taking on
this bear of a task. The US Census Bureau
is using SRC's Allocate data engine (under the "Census 2000 Data Engine"
name) to deliver Census 2000 and
SRC is offering a whole bunch of enhancements available in several
different bundles. Pulling the data out linked to
any set of geographies in either ArcView or MapInfo format is one of them.
It will save you a TON of time and money.
The first release of the Census 2000 Data Engine will be the National SF1
file, all delivered on a single DVD. It should be released by the Census
Bureau very soon, within the next week or so. All the data for Summary
Files 2 through 4 will all be delivered with this same data engine on CD
and DVD. These enhancements we are offering can be used with all the
Census 2000 data releases, not just SF1.
Please see our Census 2000 Add-on website
http://www.extendthereach.com/census_add_on for more details on all the
available add-on options.
Please don't hesitate to contact SRC at 1-888-836-4274 or via e-mail at
census_add_on@extendthereach.com with any further questions.
Thanks,
Kent Hargesheimer
SRC - Extending the Reach of Micromarketing
603 Chadfield Way NE
Leesburg, VA 20176-4823
tel 703-737-7739 fax 703-737-7719
cell 571-213-9459
http://www.extendthereach.com
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