Functions for computing: (1) the adaptive normal plug-in(PI) density estimate for data after the logarithmic transformation; (2) the adaptive log-normal PI density estimate for data after the power transformation with an exponent ranging from zero to one; (3) the single-bandwidth PI density estimate for data after the logarithmic transformation; (4) the single-bandwidth PI density estimate for data after the power transformation; (5) the data-driven bandwidth for the single-bandwidth PI estimator for data after the logarithmic transformation; (6) the rule-of-thumb bandwidth for the single-bandwidth PI estimator for data after the power transformation. For details, see the articles: (1) Savchuk, O. (2026) (submitted). Adaptive log-normal plug-in density estimator for power transformations. (2) Savchuk, O. (2026). Density estimation for log-transformed data. Computational Statistics, 41(98)