Version 3.0 - January 2021

 o Bugfixes
   * an option to specify that the input files do not contain headers (the default assumption is that both simulated and observed data files have headers naming columns) has been added to the autonpde function

 o New features (see details in the PDF documentation and the online help files)
   * all graphs have been recreated using the ggplot2 library
   * graphs of npde with a reference profile included to show the evolution of the process being modelled


Version 2.0 - August 2012

 o Bugfixes
   * none

 o Manuals
   * the user guide has been updated to include the new methods and datasets
   * an additional guide has been created to showcase the different graphs in the npde package; it contains many examples of graphs and shows how to fine-tune graphical options
   * both guides can be found in the inst directory of the package

 o New features (see details in the PDF documentation and the online help files)
   * new methods to handle the data below the LOQ
   * prediction bands: added prediction bands to scatterplots, distribution plots
   * covariate models: tests for covariate models; option covsplit added to the scatterplots and distribution plots
   * different methods for decorrelation (default method: Cholesky)

 o Reprogrammed using S4 classes; main changes include:
   * the structure of the output has changed: an object of class npdeObject is now created by a call to npde or autonpde
   * methods (special functions) plot, summary are now available and apply to the npdeObject object
       - all methods can be called simply as e.g. plot(x) where x is an object of class npdeObject (see documentation)
       - options for graphs and methods are stored in lists within the object and can be modified on the fly
   * new methods have been defined
       - the function testnpde() has been changed to the method npde()
   
 o Additional changes
   * the default option is now to compute the pd (calc.pd=TRUE)
   * the option "output=TRUE" has been removed; the npde and autonpde return a value which can be assigned to an object, but which remains invisible (not printed) when not assigned
   * a "method" option has been added to the call to autonpde; method="cholesky" uses the Cholesky decomposition to compute a square root of the individual variance-covariance matrix Vi; method="inverse" uses the inverse of Vi obtained through diagonalisation); method="polar" uses a combination of Cholesky decomposition and diagonalisation to obtain the same inverse (more stable)
   * a "continuous" option has been added; if TRUE, the distribution of pd is made continuous (default=XXX)
   * a "centering" option has been added; if TRUE, the distribution of pd is centered by substracting 1/(2K) so that pmin=1/(2K) and pmax=1-1/(2K); if FALSE, pmin=1/K and pmax=1, which was the default in the previous version of npde (default=XXX)

Version 1.2 - November 21st, 2007

 o Bugfixes
   * removed the warnings appearing at compilation with later versions of R (changes in the syntax of the man pages)

Version 1.1 - January 24th, 2007

 First version released on CRAN
