The Inverse-Weibull proves useful for modelling the childhood and teenage years,
because the logarithm of h(x) is a concave function.
m > 0 is a measure of location
sigma > 0 is measure of dispersion
Usage
invweibull(x, par = NULL)
Arguments
x
vector of age at the beginning of the age classes
par
parameters of the selected model. If NULL the
default values will be assigned automatically.