Changes in version 0.6-70 (2020-10-11)                 

    o   parallelization of lnre.bootstrap(), using forked processed on Unix-like platforms
	or with a properly initialized snow cluster (based on the 'parallel' package)

    o   bootstrapped confidence intervals in lnre() are speeded up substantially

    o   additional productivity measures and some other improvements to productivity.measures()

    o   lnre.productivity.measures() computes approximate expectations for samples from LNRE
	population or estimates sampling distribution by parametric bootstrapping

    o   plot.tfl() now also plots relative frequencies (pmw) for comparison across
	different sample sizes, as well as population distributions described by LNRE models

    o   plot method (plot.lnre) for LNRE models, showing either the log-transformed type
	density function or the distribution function for a quick visualisation

    o   all plot methods accept list of objects in first argument to avoid do.call() trickery,
	but need to be called explicitly rather than via method dispatch in this case

    o   lnre() now allows a user-defined cost function in parameter estimation (e.g to fit
	against Zipf ranking = top part of TFL, or to set parameters based on implicit constraints)

    o   bug fix: tfl2spc() no longer includes types with f = 0 in frequency spectrum, and
	spc() now complains in such cases

    o   new default colour scheme and line styles

                 Changes in version 0.6-66 (2019-10-01)                 

    o   default minimization algorithm changed to "Nelder-Mead", since "Custom" often
	failed to converge on problematic data sets

    o   new default cost function "gof" based on the multivariate chi-squared statistic,
	which is closely related to maximum likelihood estimation

    o   parameter optimization now performs multiple runs with different random start
	values by default, improving robustness of the parameter estimation

    o   lnre.bootstrap() implements parametric bootstrapping from an LNRE model, and
	the function bootstrap.confint() provides robust estimates of confidence limits

    o   rlnre() can directly generate type-frequency lists instead of token vectors,
	which is much more efficient for large samples (and essential for large-scale
	bootstrapping experiments)

    o   bootstrapped confidence intervals for model parameters can be obtained with
	confint() applied to an LNRE model object with bootstrap replicates

    o   compute various productivity measures from observed frequency spectrum,
	type-frequency list, vocabulary growth curve or token vector

    o   merge() method for two or more type frequency lists

    o   new example data sets from Evert & Luedeling (2001) and Baayen (2001)

                 Changes in version 0.6-10 (2017-08-17)                 

    o   maintenance release for compatibility with new CRAN checks and restrictions

    o   zipfR plotting utilities (zipfR.begin.plot, zipfR.end.plot, etc.) are deprecated;
	device="x11" and device="quartz" now both open the default device with dev.new(),
	which is not guaranteed to be an on-screen device

    o   update stale URLs and maintainer e-mail addresses

                        Changes in version 0.6-8                        

    o   zipfR tutorial has been rewritten as genuine package vignette

    o   write.tfl() and read.tfl() now allow character encoding of the disk file to be
	declared; read.tfl() safely reads type strings containing quotes

                 Changes in version 0.6-6 (2012-04-03)                  

    o   interim release for compliance with new, stricter CRAN requirements

    o   Zipf-ranking plots for type-frequency lists (of class "tfl")

    o   file I/O automatically compresses/decompresses ".gz" files in functions
	read.tfl(), read.spc(), read.vgc(), write.tfl(), write.spc(), write.vgc()

    o   dropped support for very old R versions (before 2.3.1 or so),
	where read.delim() does not accept comment.char= option; now requires 2.10.1+

    o   removed zipfR.legend() function since standard legend() now offers the same
	convenient placement options

    o   added citation details (file inst/CITATION), which can be displayed with
	citation(package="zipfR")

    o   upgraded to GPL v3

                 Changes in version 0.6-5 (2008-11-16)                  

    o   moved development to SVN repository on R-Forge

                        Changes in version 0.6-4                        

    o   various bug fixes and minor improvements

    o   improved robustness and tolerance for rounding errors in expected frequency spectra

                        Changes in version 0.6-2                        

    o   added function read.multiple.objects to do just that

                        Changes in version 0.6-1                        

    o   bugfix: read.vgc() died on input files without at least a V1 column

                 Changes in version 0.6-0 (2006-08-23)                  

    o   first public release on CRAN

    o   improved parameter estimation, can be fine-tuned by users
	with choice of cost functions and minimization algorithms

    o   default settings work well for most data sets

    o   minor bug fixes and improved documentation

    o   updated version of tutorial

                        Changes in version 0.5-0                        

    o   first beta release of the zipfR toolkit