help multibar
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Title

Bar and dot graphs for use with overlapping over() categories


Syntax

        multibar varlist [if] [in] [, options]

    options                           Description
    -------------------------------------------------------------------------
    Main
      percent                         display results on a percent scale
      gnumber(#)                      number of categories. Required option
      catlabels(string)               category labels. Required option
      statistic(string)               statistic represented in bar or dot
                                        graph
      type(string)                    bar, hbar or dot. Required option
      list                            displays numeric results
    -------------------------------------------------------------------------

Description

    multibar creates bar and dot graphs for overlapping over() categories.
    multibar is a wrapper for Stata's graph bar and graph dot. When entered
    correctly, multibar treats overlapping catgories as if they are not
    overlapping and, therefore, allows use of over().



Options

        +------+
    ----+ Main +-------------------------------------------------------------

    percent displays results as percents.

    gnumber (#) is the number of categories. This option is required.

    catlabels (string) are the labels given to the categories. See example.

    statistic (string) is the statistic to be represented in the bar or dot
        graph. Default is mean. See collapse for allowed statistics. Weights
        are not supported.

    type (bar, hbar, dot) selects the type of graph. This option is required.

    list displays numeric results.


Remarks

    Each yvar is a group of variables that is treated as a category level.
    All of the levels together form the over() category. Suppose we have
    panel or longitudinal data in which subjects take drugs (treatments) at
    two (or more) times. For example, Drug A can be used at baseline entry
    into the cohort and at the final observation in the cohort. We are
    interested in displaying the proportion (or percent) usage of drugs A, B,
    C at the baseline and final obervation. The group of these three drugs is
    an overlapping group because persons can receive one or more of the drugs
    at any time. Stata's graph bar, hbar and dot cannot handle this type of
    category. multibar, using collapse, preserve, and restore creates a
    result set to enable this type of categorization.

    In the example above, we have drugAfirst, drugAlast, drugBfirst,
    drugBlast, drugCfirst, drugClast. Drugs have to be arranged this way:
    (drugAfirst drugBfirst drugCfirst) (drugAlast drugBlast drugClast).
    drugAfirst and drugAlast will form the the first of the three categories
    in this example. The drugs will need a label because they are newly
    created composite variables. Use catlabels() to do this. The data have to
    be entered with the ordering noted above. The parentheses are not
    necessary, but can help in making the lists easier to read. There are
    three categories in this example, and this information must be entered
    into the gnumber() option as gnumber(3).

    "first" and "last" in the above example are treated as "variables," but
    are newly created by the program. To be meaningful they need to be added
    with legend descriptions, as shown in the example below.


Examples

    To install test dataset, type ssc describe multibar and follow
        instructions.

    . use multibar, clear

    . multibar (fprednisn fmtxa ftnf fplaquinl fazulfidn) (bpred bmtxa btnf
        bplaq bazulf), gnumber(5) catlab(1 Prednisone 2 MTX 3 TNF 4 HCQ 5
        SSZ) p legend(label(1 Baseline) label(2 "At index observation"))
        yline(37) type(dot)

Author

    F. Wolfe fwolfe@arthritis-research.org.

Acknowledgements

    Nick Cox made very helpful suggestions.


Also see