m.in.pl94.db3

NAME

m.in.pl94.db3 - Import Demographic records from Census PL94-171 dBase3 (CDROM) Files
(GRASS Sites Program)

SYNOPSIS

m.in.pl94.db3 help
m.in.pl94.db3 [-f] [-p] [-n] sc=string [ sc=str . . ] in=/cdrom/pl9417ss.dbf > result_file

This command may be run in command line mode only. Parameters used must be in the order specified.

OPTIONS

Flags:

-f: Output to stdout the list of all field name and starting positions
for the Identification Section of the PL94 file. Other
parameters are not necessary and will be ignored.
-p: Print several information items to stderr input
file is opened.
-n: Output only the sequential number and PL94 logical record
number (LOGRECNU) of matching records to stdout.

Parameters:

sc=string: sc is starting column or a capitilized reference name from the Identification Section of the PL94 Data Dictionary; string is characters to match there. A negative test may also be made with: sc!=string. If more than one test is specified the results are "anded" resulting in a conjunction of the results of the expressions. (See m.in.stf1.tpe for complete details.)
in=name: Path/file for dBase files for state ss.

DESCRIPTION

This program is provided to read the Census PL94 data records from a file for one state. The file is usually on a CD-ROM, but this is not necessary providing the proper path is given for the in= parameter and the contents of the file duplicate that on CD-ROM.

The output consists of records of 517 characters extracted from the input file with a suitable line termination character added (\n) to create a normal text file.

Users of GRASS 4.1 and the Census PL94 files on CD-ROM will generally use this program to select appropriate subsets of PL94 records; write them to one or more files; and then either process these files directly with v.apply.census to print demographics, create site maps or label vector maps, or use m.in.stf1.tpe to extract further subsets.

The PL94 CD-ROM data file for most states is very large, 100+ MB. This program may take 20 to 60 minutes for a single extraction, so plan carefully and don't discard useful subsets that you create on disk.

EXAMPLES

Insert the appropriate CD-ROM and mount it (see your system administrator). (We assume here that it is mounted as the file system /cdrom.)

To extract all Census tract summary records for the state of South Dakota:

m.in.pl94.db3 -p 11=050 in=/cdrom/pl9417sd.dbf > counties.sd

The 11=050 parameter selects those records which have the character string '050' beginning in column 11 of the assembled records. Columns 11-13 are the Summary Level (SUMLEV) field which is used in almost every selection from CD-ROM.

To extract all block records for Lawrence County, South Dakota:

m.in.pl94.db3 -p SUMLEV=100 CNTY=081 in=/cdrom/pl9417sd.dbf > bk.081.sd

100 is the SUMLEV for blocks and 081 is the county code for Lawrence Co.

AUTHOR