For the one-component gambin model the confidence interval for the
alpha parameter is calculated automatically using an analytical solution.
For gambin models with more than one component no analytical solution for
deriving the confidence intervals is known. Instead, a bootstrapping
procedure can be used (using the confint
and n
arguments) to
generate confidence intervals around the alpha and max octave parameters.
However, the process can be time-consuming, particularly for gambin models
with more than two components. Thus, the default is that confidence
intervals are not automatically calculated for gambin models with more than
one component (i.e. confint
== FALSE).
In addition, it should be noted that in certain case the confidence
intervals around the alpha parameters in multi-component gambin models can
be quite wide. This is due to changes in the max octaves of the component
distributions in the bootstrapped samples. It can be useful to make a plot
(e.g. a dependency boxplot) of the n alpha values against the max octave
values.