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help for wtddiag
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Diagnostic plots for Waiting Time Distribution data

        wtddiag, barsize(#) [cutpt(date) frmodels(fr_mods)
                hdmodels(rate_mods) cens(cens_type) noiest twoway_opts]

    wtddiag is for use with Waiting Time Distribution data; see help wtd. You
    must wtdset your data before using this command; see help wtdset.


Notes on syntax

    fr_mods is a string consisting of one or more of the letters 'e', 'l',
        and 'w' in arbitrary order.

    rate_mods is a string consisting of one or more of the letters 'e' and
        'u' in arbitrary order.

    cens_type is one of

            depphi | dep | indep | none


    twoway_opts are options for twoway, see help twoway.

Description

    wtddiag makes a histogram of the observed Waiting Time Distribution and
    allows adding both an ad-hoc estimate based on a chosen cut-point as well
    as parametrically fitted density/ies based on wtdml, see help wtdml.


Options for wtddiag

    barsize(#) specifies the width of bars in the histogram. The unit of
        barsize() is days.

    cutpt(date) specifies the cut-point after which all observed events are
        considered to arise from incident subjects. A vertical line is added
        to the plot at the cut-point, together with a horizontal line
        indicating the estimated incidence level. Finally, a table is
        displayed with information on estimates of prevalence and incidence
        based on the chosen cut-point. The date must be specified with syntax
        acceptable by the d() function, see help dfcn.

    frmodels(fr_mods) specifies the forward recurrence densities used in
        defining the models to be fitted. 'e' denotes Exponential, 'l'
        Log-Normal, and 'w' Weibull, see help wtdml.

    hdmodels(rate_mods) specifies the densities used for incidence and exit
        rates in defining the models to be fitted. 'e' denotes Exponential
        and 'u' Uniform, see help wtdml.

    cens(cens_type) specifies the dependency structure between event and exit
        times and follows the syntax for wtdml, see help wtdml.

    noiest requests display of maximization process(es) and output(s).

Examples

    . wtdset event exit, i(id) start(31dec1996) end(31dec1997) scale(365)

    . wtddiag, barsize(14) cutpt(1oct1997)

    . wtddiag, barsize(14) frmodels(ew) hdmodels(e) cens(depphi)

    . wtddiag, barsize(14) saving(diagplot.gph) /* save copy of plot */


Also see