NEWS.md

In xnicher: Estimates Ecological Niche Models Using Ellipses

xnicher 1.0.0

CRAN release

This is the first CRAN release of xnicher (formerly developed as nicher) for fitting ecological niche models with ellipsoidal environmental responses under the M hypothesis.

Model families

• optimize_niche() supports nine likelihood families: presence_only, weighted, ip_weighted, skew_normal, skew_normal_weighted, skew_t, skew_t_weighted, ncst, and ncst_weighted.
• Weighted families (weighted, ip_weighted, and their skew variants) use M-background environmental data through env_m.
• Non-symmetric families (skew_normal, skew_t, ncst, and their weighted variants) model asymmetric or heavy-tailed environmental responses.

Model comparison and validation

• S3 methods for logLik(), AIC(), BIC(), and nobs().
• compare_xnicher() for side-by-side model comparison.
• cv_xnicher() for k-fold and leave-one-out cross-validation of fitted xnicher objects.

Documentation

• Vignettes covering the getting-started workflow, cross-validation, all weighted/non-symmetric likelihood families, and the Rhipicephalus microplus example with iso-suitability and geographic maps.
• README examples cover the main model families.

xnicher documentation built on Sept. 15, 2026, 5:08 p.m.