help cfby
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Title

    cfby -- Compare two files to get the number differences "by" a common varia
> ble

Syntax

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

    options               Description
    -------------------------------------------------------------------------
      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