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help for dummieslab
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Generating dummy variables from categorical variable using value label names

        dummieslab varname [if exp] [in range]
                 [, word(integer) from(string) to(string) template(string)
                 truncate(integer) novarlabel ]


Description

    dummieslab generates a set of dummy variables from a categorical
    variable. One dummy variable is created for each level of the original
    variable. Names for the dummy variables are derived from the value labels
    of the categorical variable. (Raw (unlabelled) values are used if the
    categorical variable has no value labels attached.)

    Two different behaviours can be chosen for the variable names:  (i) use
    full value labels; (ii) use the sth word of the label. In both cases, all
    invalid characters are stripped from the new variable names.

    Any user-defined prefix and/or suffix can be added using the template
    option.

    In all cases, no new variable will be generated unless all implied new
    names are valid.

    dummieslab applied to variables with no label appends the level to the
    original variable name (very much like what tabulate does).


Options

    word(s) requests that the sth word of the label be used as the new
        variable name. Note the use of word(-1) to specify the last word of
        the label.

    from(string) and to(string) are used together to make replacements to the
        strings used to create the new variables. from(string) contains a
        list of words to be replaced by the list of words supplied in
        to(string), i.e. the first item in from is substituted by the first
        item in to, the second item in from is substituted by the second item
        in to, etc.  By default, all invalid characters are dropped from the
        value labels to create new variable names. This behaviour can be
        overridden by the use of from(string) and to(string). For example,
        use from(" ") and to("_") to replace all blanks by underscores.

    template(word)  specifies a template for the new variable name. @ is used
        as a placeholder for inserting the extracted label. This option is
        used to insert a prefix (anything before @ in word) and/or a suffix
        (anything after @ in word).

    truncate(n) truncates new variable names after n characters.

    novarlabel prevents automated variable labelling of the generated
        dummies.


Saved results

    local
      r(names)   List of names of created dummies
       r(from)   Name of the original categorical variable


Examples

    . sysuse auto
    . label define newfor 0 "Domestic car" 1 "Foreign (European or Japanese)
        car"
    . label values foreign newfor
    . dummieslab foreign
    . dummieslab foreign, word(1)
    . dummieslab foreign, word(-1)
    . dummieslab foreign, from(" ") to("_")
    . dummieslab foreign, from(car or Foreign) to("" "_" "")
    . dummieslab foreign, from(car Foreign or) to("" "" "_")
    . dummieslab foreign, word(1) template("My_@_car")


Acknowledgments

    Patrick Joly made helpful suggestions on the first version of dummieslab,
    which led to the addition of the from and to options. Daniel Klein
    suggested option novarlabel.


Authors

    Philippe Van Kerm, CEPS/INSTEAD, Differdange, G.-D. Luxembourg
    philippe.vankerm@ceps.lu

    Nicholas J. Cox, Durham University, U.K.
    n.j.cox@durham.ac.uk


Also see

    On-line:  tabulate  
    On-line (if installed):  dummies