Title: Threshold Regression that Fits the (Randomized Drift) Inverse
Description: Fits the (randomized drift) inverse Gaussian distribution to survival data. The model is described in Aalen OO, Borgan O, Gjessing HK. Survival and Event History Analysis. A Process Point of View. Springer, 2008. It is based on describing time to event as the barrier hitting time of a Wiener process, where drift towards the barrier has been randomized with a Gaussian distribution. The model allows covariates to influence starting values of the Wiener process and/or average drift towards a barrier, with a user-defined choice of link functions.

Title: Inversion of Laplace-Transformed Functions
Description: Provides two functions for the numerical inversion of Laplace-Transformed functions, returning the value of the standard (time) domain function at a specified value.  The first algorithm is the first optimum contour algorithm described by Evans and Chung (2000)[1].
The second algorithm uses the Bromwich contour as per the definition of the inverse Laplace Transform.  The latter is unstable for numerical inversion and mainly included for comparison or interest.  There are also some additional functions provided for utility, including plotting and some simple Laplace Transform examples, for which there are known analytical solutions.  Polar-cartesian conversion functions are included in this package and are used by the inversion functions.
[1] Evans & Chung, 2000: Laplace transform inversions using optimal contours in the complex plane; International Journal of Computer Mathematics v73 pp531-543.

Title: Analyse Biological Invasion Costs with the 'InvaCost' Database
Author: Boris Leroy [cre, aut], Andrew Kramer [aut], Anne-Charlotte Vaissière [ctb], Christophe Diagne [ctb]
Description: Provides an up-to-date version of the 'InvaCost' database
several functions to analyse the costs of invasive alien species.
Imports: dplyr, earth, graphics, grDevices, lmtest, mgcv, quantreg,
robustbase, sandwich, scales, stats, utils