The modal interval, i.e. the shortest interval among intervals containing
k+1 observations, is first computed. (In dimension > 1, this question
is known as a 'k-enclosing problem'.)
The user should either give the bandwidth bw or the argument k,
k being taken equal to ceiling(bw*n) - 1 if missing, so
bw can be seen as the fraction of the observations to be considered
for the shortest interval.
If type = 1, the midpoint of the modal interval is returned.
If type = 2, the floor((k+1)/2)th element of the modal
interval is returned.
If type = 3 or type = "dalenius", the median of the modal
interval is returned.
If type = 4 or type = "shorth", the mean of the modal interval
is returned.
If type = 5 or type = "ekblom", Ekblom's
\(L_{-\infty}\) estimate is returned, see Ekblom (1972).
If type = 6 or type = "hsm", the half sample mode (hsm) is
computed, see hsm.