AdequacyModel

The AdequacyModel is a computational library for the R statistical environment that provides tools for fitting survival data using various lifetime distributions. The library introduces two major contributions:

1. A general optimization technique based on a modified Particle Swarm Optimization (PSO) method is beneficial for obtaining maximum likelihood estimators in cases where derivative-based optimization tools are unsuitable due to flat regions in the search space.

2. A set of statistical measures for assessing the adequacy of the fitted model, allowing researchers to evaluate the goodness-of-fit of the chosen lifetime distribution.

The AdequacyModel library has been widely used and cited in the fields of probability and statistics. It serves as the foundation for several other R packages, including Newdistns (version 2.1), Wrapped (version 2.0), and sglg. These packages, built upon the AdequacyModel library, have been published in impact journals and are available on the Comprehensive R Archive Network (CRAN).

The library offers greater control over the optimization process by introducing a stop criterion based on a minimum number of iterations and the variance of a given proportion of optimal values. This feature makes the AdequacyModel library useful for maximizing log-likelihood functions with complex search regions.

Although primarily designed for applications in statistics, the AdequacyModel library has also proven to be valuable in physics and mathematics, as demonstrated through various examples in the associated paper.