-------------------------------------------------------------------------------
help for  mimerge                                               (SJ3-3: st0000)
-------------------------------------------------------------------------------

Merge multiple (imputed) datasets

        mimerge [varlist] using filename-prefix [, keep(varlist) unique
                           uniqmaster uniqusing nolabel nokeep
                           _merge(varname)]


Description

    mimerge joins corresponding observations from each of the miset datasets
    with each of the using datasets into single observations.


Options

    keep(varlist) specifies the variables to be kept from the using data.  If
        keep() is not specified, all variables are kept.

    unique, uniqmaster, and uniqusing specify that the match variable(s) in a
        match merge uniquely identifies the observations.

        unique specifies that the match variable(s) uniquely identifies the
        observations in the master data and in the using data.  For most
        match merges, you should specify unique.  merge does nothing
        differently when you specify the option, unless the assumption that
        you are making is false.  In that case, an error message is issued
        and the data are not merged.

        uniqmaster specifies that the match variable(s) uniquely identifies
        the observations in memory, the master data, but not necessarily the
        ones in the using data.

        uniqusing specifies that the match variable(s) uniquely identifies
        the observations in the using data, but not necessarily the ones in
        the master data.

    nolabel prevents Stata from copying the value label definitions from the
        using dataset.

    nokeep causes merge to ignore observations in the using data that have no
        corresponding observation in the master.

    _merge(varname) specifies the name of the variable that will mark the
        source of the resulting observation. The default is _merge(_merge).

    These options are all inherited from the parent merge command.


Remarks

    The master datasets should be miset before using mimerge.  The number of
    using datasets must be the same as that of the master datasets.  The
    names follow mi naming conventions, see help miset.


Examples

    Assume foo1.dta to foo5.dta have variables id and drkfre, and bar1.dta to
    bar5.dta have variables id and smk. By issuing

    . miset using foo
    . mido sort id
    . misave foo, replace
    . miset using bar
    . mido sort id
    . mimerge id using foo
    . misave foobar

    the dataset foom.dta is merged to barm.dta to form a new dataset
    foobarm.dta (m = 1,...,5), which contains variables id, drkfre, and smk.


Authors

    Ning Li, Philip Greenwood, and John Carlin, Clinical Epidemiology &
    Biostatistics Unit, Murdoch Children's Research Institute and University
    of Melbourne. Email jbcarlin@unimelb.edu.au


Also see

    Online: help for merge, miset, miappend, misave, mido, mici, mifit, 
              milincom, mireset