..-
help for ^marker^
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Mark sample with all values present for later use
-------------------------------------------------

        ^marker^ [varlist] [weight] [^if^ exp] [^in^ range]
        [^,^ ^g^en^(^markvar^)^ ^st^rok]

Description
-----------

^marker^ creates a 0-1 variable markvar, such that markvar has value

    1 if all values are present (not missing) for every variable in varlist
         and have sensible non-zero weights if weights are specified
         and satisfy any ^if^ or ^in^ condition specified

    and

    0 otherwise.

The name of markvar defaults to ^_marker^, providing that is not already
in use.

The main use of ^marker^ is to define samples so that the results of
commands that automatically ignore any observations with missing values
on any of the variables specified (e.g. ^regress^) are comparable with
the results of other commands that do not do this (e.g. ^summarize^).
Once the sample has been defined, it can be specified by

    ... ^if ^markvar^ == 1^

or even more concisely by

    ... ^if ^markvar

Options
-------

^gen(^markvar^)^ specifies the name of a new variable for markvar.

^strok^ indicates that non-missing string values (i.e. values other than
    the empty string "") are acceptable for any string variables in
    varlist as defining present observations.


Examples
--------

    . ^marker rep78^
    . ^su if _marker^

    . ^regress a b c d e^
    . ^marker a b c d e, g(regdata)^
    . ^su if regdata^

Author
------

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


Also see:
--------

 On-line: help for @mark@
  Manual: [R] mark