Data with many small or large cause no problems with the method
in theory. Moreover, data like these produce estimates with very
narrow bounds (since the tomography lines cut off the top right or
bottom left corner of the plot). This is good news for estimation,
although if the difference between, say,
and
is substantively large (as for mortality rates),
what might otherwise be considered ``narrow'' bounds (such as
[0,0.05]) could in some cases still be too wide for particular
substantive purposes, so be careful about interpretation. To read the
graphs, it is helpful to zoom in on the relevant regions, by setting
globals such as _eigraph_Xlo, _eigraph_BBhi,
etc. Be sure to check and probably reduce the global
_EnumTol, since the default value (0.0001) would define some
data sets as unanimous () for too many observations. Beware
also of other numerical problems with data like these (by verifying
the fit of the contours to the data with eigraph's tomogS and
fit), since the contours must be fit to a very small area of
the tomography plot and so calculating the cdf of the truncated
bivariate normal can be imprecise. It is often necessary to use
better starting values (see _Estval) and search constraints
(_Ebounds) than the defaults. The grid search procedure can
also be helpful (_Estval). Since odds are you want to
distinguish between very small differences in the quantities of
interest, you will probably also wish to increase the number of
simulations substantially (_Esims). Finally, posterior
densities from EI are rarely normal or symmetric in the presence of
rare events, and in this situation mean posterior point estimates are
not good summaries of EI's inference in these situations. Better
would be to use a density estimate of the simulations, such as
eigraph's post option.