ModalCens 0.3.1
- Bug fix for
family = "invgauss": the optimizer could
stop at a spurious solution on the boundary
lambda = 3 * max(mode) of the feasible region when the
fixed starting values were far from the data. A second, data-driven
starting point (least squares coefficients and a moment-type
lambda inside the feasible region) is now also tried, and
the solution with the larger likelihood is returned. Fits that were
already correct are unchanged.
- Bug fix for
family = "beta": the inverse logit is now
evaluated in an overflow-safe way. Extreme trial values of the linear
predictor during the line search could produce NaN and stop
the fit with an error, which was observed mainly under heavy
censoring.
family = "beta" also tries a second starting point
(least squares coefficients) and keeps the solution with the larger
likelihood. Under heavy censoring the default start could lead to a
degenerate solution with phi close to zero.
ModalCens 0.3.0
- Added the Log-t (
"logt") distribution family, in which
the logarithm of the response follows a Student-t distribution. The mode
is reparameterized in closed form, and the family supports
right-censoring and randomized quantile residuals. It reduces to the
Log-Normal family as the degrees of freedom grow.
- New argument
nu in modal_cens() for the
degrees of freedom of the Log-t family, treated as known (default
4). It is ignored by the other families.
summary() reports the degrees of freedom when
family = "logt", and the fitted object stores them in the
new element nu.
- A warning is issued when the Log-t dispersion estimate lies at the
boundary of the region that guarantees an interior mode.
ModalCens 0.2.0
- Added the Log-Logistic (
"loglogistic") and
Birnbaum-Saunders ("bisa") distribution families, providing
highly flexible modeling options outside the exponential family
framework. Both support mode reparameterization, right-censoring, and
randomized quantile residuals.
- Added a caveat in the documentation regarding the strong parametric
restriction of the Inverse Gaussian distribution.
- Added the Log-Normal (
"lognormal") distribution family,
with mode reparameterization, right-censoring support, and randomized
quantile residuals.
ModalCens 0.1.0