where y > 0, c > 0 and 0 < s < 1.
The mean, (c *
(s - 1)/ s) * log(1 - s)
is returned as the fitted values.
Note the median is c * log(2 - s).
Simulated Fisher scoring is implemented.
Value
An object of class "vglmff" (see vglmff-class).
The object is used by modelling functions such as vglm
and vgam.
Note
We define scale as the reciprocal of the scale parameter
used by Adamidis and Loukas (1998).
Author(s)
J. G. Lauder and T. W. Yee
References
Adamidis, K., Loukas, S. (1998).
A lifetime distribution with decreasing failure rate.
Statistics and Probability Letters,
39, 35–42.