Calculates Pearson, Spearman, polychoric, and polyserial correlation coefficients, in weighted or unweighted form. The package implements tetrachoric correlation as a special case of the polychoric and biserial correlation as a specific case of the polyserial.

A new inverse probability of selection weighted Cox model to deal with outcome-dependent sampling in survival analysis.

Calibrates Bayesian two-stage designs for single-arm phase II trials with
    time-to-event endpoints using a window-cohort with controlled roll-on.
    Interim monitoring is anchored to a locked interim cohort and a
    pre-specified follow-up requirement, so analysis timing remains
    predictable while preserving follow-up maturity. The package searches
    feasible interim rules, optimizes final sample size and decision
    thresholds, evaluates operating characteristics by Monte Carlo simulation,
    and supports exponential, Weibull, log-normal, log-logistic, and
    user-defined baseline survival models. Related published foundations
    include Simon (1989) <doi:10.1016/0197-2456(89)90015-9> and Cotterill and
    Whitehead (2015) <doi:10.1002/sim.6426>.

Provides workflows to prepare weather and climate time series from
    gridded and station data for 'SWAT' ('Soil and Water Assessment Tool').
    Supports data extraction, aggregation, interpolation, quality control, unit
    conversion, and export of per-location model input files. For the underlying
    model, see Arnold et al. (1998) "Large Area Hydrologic Modeling and
    Assessment Part I: Model Development"
    <doi:10.1111/j.1752-1688.1998.tb05961.x>.

Standardizes and reconciles scientific plant names against
    a World Checklist of Vascular Plants ('WCVP')-style taxonomic
    backbone. The package parses names into taxonomic components and
    applies staged exact and fuzzy matching for binomial and trinomial
    inputs, including infraspecific rank-aware checks. It also returns
    accepted-name context and row-level matching flags to support
    reproducible, auditable preprocessing for downstream biodiversity,
    spatial, and trait analyses. A user-supplied backbone can be passed
    through 'target_df'; when the optional companion package 'wcvpdata'
    is installed, its default checklist can also be used.