News

RELEASE HISTORY OF THE "zCompositions" PACKAGE

CHANGES IN zCompositions VERSION 1.1.1 [2017-08]:

NEW FEATURES

• lrEM now allows to impute missing data.
• zVarArray: variation arrays by zero/unobserved data patterns or groups.
• zVarArrayError: squared relative errors in variation arrays across groups.
• zVarArrayTest: homogeneity test of variation arrays across groups.
• lcTest: homogeneity test of log-contrast across groups.

MODIFICATIONS

• Improved documentation.
• Verbosity controlled throughout by suppress.print argument.
• zPatterns: argument to show means (geometric or arithmetic) by pattern included.

CHANGES IN zCompositions VERSION 1.0.3-1 [2016-04]:

MODIFICATIONS

• References updated and adaptation to new CRAN policies.

CHANGES IN zCompositions VERSION 1.0.3 [2014-09]:

NEW FEATURES

• Support for multiple limits of detection/threshold values by component.
• Choice for storing multiply imputed data sets in lrDA function.
• multKM: new non-parametric imputation method added.
• splineKM: visualisation of Kaplan-Meier and cubic spline smoothed empirical cumulative distribution function (helper function for multKM).
• New example data set included (Water).

MODIFICATIONS

• Alternative imputation by multRepl in lrEM and lrDA of censoring patterns with only one observed component.

• Fixed problem that caused error when a censoring pattern consisted of a single sample.

• Improved documentation.

CHANGES IN zCompositions VERSION 1.0.1 [2014-06]:

• Minor bugs in error messages fixed.

• cmultRepl: label argument added (default label = 0).

CHANGES IN zCompositions VERSION 1.0.0 [2014-05]:

NEW FEATURES

• cmultRepl function: bayesian-multiplicative replacement of compositional count zeros included.

• lrDA function: data augmentation algorithm, including multiple imputation, to replace left-censored values.

• zPatterns function: summarises the patterns of unobserved values (censored, nondetects, ...) in a data set and generates a vector of labels.

MODIFICATIONS

• General revision and optimisation. Documentation improvements.

• multLN: parameter estimates based on the normal distribution on the positive real line. Random imputation based on truncated normal instead of rejection method.

• Re-scaling to preserve ratios that leaves absolute observed values unaltered when working with non-closed data now implemented for all the methods (continuous data).

• The replacement methods include an argument 'label' allowing the user to enter the label (special character, number, ...) denoting unobserved value in a data set.

• Error handling introduced.

• New lrEM function: replaces previous alrEM function and implements both ordinary and robust EM-based imputation methods. New arguments allow to specify the method to obtain initial estimates and the convergence criterion.

Reference manual