Provides various tools for analysing density profiles
    obtained by resistance drilling. It can load individual or
    multiple files and trim the starting and ending part of each
    density profile. Tools are also provided to trim profiles
    manually, to remove the trend from measurements using several
    methods, to plot the profiles and to detect tree rings
    automatically. Written with a focus on forestry use of resistance
    drilling in standing trees.

With bivariate data, it is possible to calculate
    2-dimensional kernel density estimates that return polygons at given
    levels of probability. 'densityarea' returns these polygons for
    analysis, including for calculating their area.

An improved implementation (based on k-nearest neighbors) of
    the density peak clustering algorithm, originally described by Alex
    Rodriguez and Alessandro Laio (Science, 2014 vol. 344). It can handle large 
    datasets (> 100,000 samples) very efficiently. It was initially implemented 
    by Thomas Lin Pedersen, with inputs from Sean Hughes and later improved by 
    Xiaojie Qiu to handle large datasets with kNNs.

Fast, flexible and user-friendly tools for distribution comparison
  through direct density ratio estimation. The estimated density ratio can be 
  used for covariate shift adjustment, outlier-detection, change-point detection,
  classification and evaluation of synthetic data quality. The package implements
  multiple non-parametric estimation techniques (unconstrained least-squares
  importance fitting, ulsif(), Kullback-Leibler importance estimation procedure,
  kliep(), spectral density ratio estimation, spectral(), kernel mean matching,
  kmm(), and least-squares hetero-distributional subspace search, lhss()).
  with automatic tuning of hyperparameters. Helper functions are available for
  two-sample testing and visualizing the density ratios. For an overview on 
  density ratio estimation, see Sugiyama et al. (2012) <doi:10.1017/CBO9781139035613>
  for a general overview, and the help files for references on the specific 
  estimation techniques.