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help multencode
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Encode multiple string variables into numeric


Syntax

        multencode strvarlist [if] [in] , generate(newvarlist) [ label(name)
                force ]


Description

    multencode creates new numeric variables newvarlist, with value labels
    defined and attached, based on the string variables strvarlist. The same
    set of value labels is used for all the new variables. By default a new
    set of labels will be created with the same name as the first variable in
    strvarlist. Optionally, a name may be specified using the label() option.
    In either case, no existing set of value labels with the same name will
    be used, unless the force option is specified, in which case those value
    labels will be over-written. In this way, the user is assured that the
    new variables will have the same alphabetically ordered set of value
    labels, provided as usual that the request does not breach any limits
    that apply.

    Do not use multencode if strvarlist contains numbers that merely happen
    to be stored as strings. Instead, use destring. See destring.


Remarks 

    multencode uses Mata to determine the distinct values of the variables to
    be encoded. Thus Stata 9 up is required.

    A multiple decode is easy enough, perhaps as easy as

        foreach v of var varlist { 
                decode `v', gen(s_`v') 
        } 

    - so long as no variable name is close enough to the limit of 32
    characters.


Options

    generate() is required and specifies the names of the variables to be
        created. Hyphenated lists such as nvar1-nvar8 are allowed.

    label() specifies the name of the value label to be created.  If label()
        is not specified, multencode attempts to use the same name for the
        label as the first existing variable specified. In neither case will
        an existing set of value labels be overwritten unless force is also
        specified.

    force specifies that any existing value labels with the same name as
        implied by other choices will be overwritten. Only rarely should this
        option be used: it may have serious consequences for other variables.
        Proceed with extreme caution and never use if in doubt.


Example

    . multencode svar1-svar8, gen(nvar1-nvar8)


Author 

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


Acknowledgments 

    This problem was suggested on Statalist by Moleps Islon.


Also see

    help for encode, destring, label