*! version 1 10may2011

cfby has been superseded by the SSC program cfout version 2.0.0.
cfby continues to run as before, but it is no longer supported.
This is the original help file, which will not be updated.

help cfby

Title

cfby -- Compare two files to get the number differences "by" a common variable

Syntax

cfby
[varlist]
using filename
, id(varname) [options]

nopunct ignores differences in punctuation and capitalization

nomatch surpress warnings about missing observations

upper convert all string variables to upper case before comparing

lower convert all string variables to lower case before comparing

nostring do not compare any string variables

Description

cfby compares the variables in varlist from the dataset in memory
to the variables in varlist from the using dataset and displays
the discrepancy rates by a common variable. It is useful if
you are doing data entry and want to get discrepancy rates of
data entry officers.

Options

id(varname) is required. varname is the variable that matches observations in
the master dataset to observations in the using dataset.
It must uniquely identify observations in both the master and using datasets.

nopunct Deletes the following characters before comparing:
! ? ' and replaces the
following characters with a space: . , - / ; and trims all extra spaces

nomatch is specified if the number of observations in the master and
using dataset do not need to match. The default is to assume 1:1 matching
between the datasets, and to list any observations that existin in only one
dataset.

Remarks

cfby is intended to be used as part of the data entry process
when data is checked for accuracy. It outputs a matrix of discrepancies
for each unique combination of values of the by variable between the master and using datasets.
So if you compared the first entry of a dataset to the second entry,
it would output the discrepancy rate for each pair of data entry officers.
If the master dataset was the result of a thoroughly checked audit
and the using dataset were the raw first entry,
simply set the by variable to a constant in the audit dataset
and cfby will output the error rate for each data entry officer in the first entry.
cfby does not compare variables that have a different	string/numeric type in both datasets.
cfby also doesn't compare variables that are different in all observations.

Examples

use "audit dataset.dta"

cfby region-no_good_at_all using "first entry.dta" , id(uniqueid) by(deo)

Saved Results

cfby saves the following in r():

Matricies

r(e) number of discrepenacies

r(q) number of data points compared

Author

Ryan Knight, rknight@poverty-action.org

Also see

Online: cf, compare

User-Written: cfout, readreplace