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help for vreverse
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Reverse existing categorical variable

        vreverse varname [if exp] [in range] , generate(newvar)
               [valuelabelname(lblname) removenumlabel mask(str)]


Description

    vreverse generates newvar as a reversed copy of an existing categorical
    variable varname which has integer values and (usually) value labels
    assigned.  Suppose that in the observations specified varname varies
    between minimum min and maximum max. Then

        newvar = min + max - varname

    and any value labels are mapped accordingly. If no value labels have been
    assigned, then the values of varname will become the value labels of
    newvar. newvar will have the same storage type and the same display
    format as varname.  If varname possesses a variable label or
    characteristics, these will also be copied. It is the user's
    responsibility to consider whether the copied variable label and
    characteristics also apply to newvar.


Options

    generate() is a required option specifying a new variable name.

    valuelabelname() specifies a name for the new value labels. By default
        newvar is used as the name for the new value labels; any existing
        value labels under that name for the values of newvar will be
        overwritten.

    removenumlabel specifies that a numeric prefix previously assigned using 
        numlabel to the value labels attached to varname should be removed
        from the value labels attached to newvar. The value labels attached
        to varname will not be modified, unless they are the value labels
        named by valuelabelname().

        Concretely, suppose you defined value labels for the values 1 to 5 of
        rep78 and then used numlabel to add numeric prefixes to those labels.
        By default, without the removenumlabel option, vreverse produces
        value labels attached to newvar that will start with "5. " "4. " "3.
        " "2. " and "1. ". Specifying the removenumlabel option will strip
        those prefixes. Note that a subsequent numlabel would add prefixes
        "1. " "2. " "3. " "4. " and "5. ". See also mask() below.

    mask() is for use with removelabel. If, and only if, some mask() was
        specified when previously using numlabel, then specify the same
        mask() now.


Examples

    . vreverse foreign, gen(Foreign)


Author

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


Acknowledgements

    Renzo Comolli pointed out an issue that can arise if numlabel had
    previously been used.

 
Also see

    Online: help for label, numlabel