to get a help
screen that explains the difference between selecting items and selecting records
for the particular file you are working with.
3. How do I get data for all counties (or other type of area) at once?
Some users intuitively feel that they ought to put an X next to every county
name in order to select all counties. They realize that doesn't work when the
Select Records menu allows no more than 14 or so specific values to be checked off.
Selecting records is a matter of restricting what records display.
If you want "all" of something, then you don't want to restrict along that
dimension. You need to figure out what differentiates the records you want
from the records you don't.
Many files have a summary level or record type code, such as GEOTYPE in the 1992
Economic Census or SUMLEV in the 1990 STF's, that allows you to differentiate
among different types of geographic areas. On the STF's, for example, you select
all county-level records by selecting SUMLEV code 050.
4. Why might I get a blank file selection screen?
The file selection screen will be blank if EXTRACT can't read the directory of
your CD-ROM or can't find any of the type of files you have selected. This can
happen if the CD-ROM drive is empty, the CD-ROM is not fully inserted, the wrong
CD-ROM is in the drive, or the wrong drive letter has been specified for the CD-
ROM.
5. How can I avoid RUN ERRORs?
EXTRACT requires 500 to 520k of RAM. If you don't know how
much memory is available, run the CHKDSK program included with DOS; the last line
of screen output tells you how much memory is available. If you have less than
500,000 or so, you may need to reboot with network drivers or TSRs (terminate-and-
stay- resident programs) removed or loaded into high memory.
The points in the program where you are most likely to encounter memory problems
are on the drive selection screen when the system is trying to offer you a menu
of master catalogs; when you are accessing a particularly long definition, such
as the STF 3 table locator; or when you are creating a extract file in .PRN format
with headers and footers.
6. What do I do if the installation program has a RUN TIME ERROR R6003?
EXTRACT's INSTALL utility does not work with certain recent Windows operating
systems. If you get a run time error, simply follow these alternate
installation instructions instead.
7. Can I program EXTRACT to do the same operations
for multiple states?
EXTRACT is not a programming language, and has no capability to save procedures
from one session or file to another. Since some databases present data for
different states in different files (e.g., STF 3a, CBP), you have to
repeat record selection and other steps a tedious 51 times to get data for all
states.
dBASE and other general database packages do have programming capabilities, and
it may be preferable to use one of them--if you have one--for the most repetitive
tasks, after you have become familiar with the census files through EXTRACT.
ALLSTATE.PRG is a sample program
written for dBASE III+ that builds a national file of data for places of 2500
or more inhabitants from the separate state specific files from STF 1a. The
program prompts the user to insert multiple CD-ROMs in succession.
You can modify the code to do analogous operations with other state-specific
files from the STFs, CBP, agriculture census, etc.
8. How can I get help using EXTRACT?
A help line is available for EXTRACT users at 301-457-4151. There are a few things
you can do if you think you have encountered a program bug.
- See if you can reproduce the problem. You may need to be able to tell the
person at the other end of the line the sequence of steps that brought you to the
problem.
- If the program terminated abruptly, i.e., "bombed", then EXTRACT left a 1-
line message at the top of the screen that may be the key to determining the
problem. Write the message down precisely, or send it to your printer with
shift-Print Screen. If you access EXTRACT through a menuing system that takes
you back to the menu without giving you time to record any error message, try to
run EXTRACT outside of the menuing system (i.e., from a C> prompt) or have your
menu designer insert a "pause" command after running EXTRACT. That way you can
record any error messages before calling for help.
- Ideally, call while you are at the computer.
Do you have your own nominee for your most frequently asked question? Send us a
message.
revised 6/27/96
