Density Estimation for Point-Centered Quarter Method with Truncated Sampling // Implements a systematic methodology for estimating population density from point-centered quarter method (PCQM) surveys when distance measurements are truncated by a maximum search radius (right-censored). The package provides a unified framework for analyzing such incomplete data, addressing both completely randomly distributed (Poisson) and spatially aggregated (Negative Binomial) populations. Key features include: (1) Adjusted moment-based density estimators for censored distances; (2) Maximum likelihood estimation (MLE) of density under the Poisson (CSR) model; and (3) Simultaneous MLE of density and an aggregation parameter under the Negative Binomial model. For more details, see Huang, Shen, Xing, and Zhao (2026) doi:10.48550/arXiv.2603.08276.