Skip to content

v0.2-0

Pre-release
Pre-release
Compare
Choose a tag to compare
@hturner hturner released this 17 Oct 09:00
v0.2-0
bf01abd

New Features

  • Add vignette.
  • Add data sets pudding, nascar and beans.
  • Add pltree() function for use with partykit::mob(). Requires new objects of type "grouped_rankings" that add a grouping index to a "rankings" object and store other derived objects used by PlackettLuce. Methods to print, plot and predict Plackett-Luce trees are provided.
  • Add connectivity() function to check connectivity of a network given adjacency matrix. New adjacency() function computes adjacency matrix without creating edgelist, so remove as.edgelist generic and method for `"PlackettLuce" objects.
  • Add as.data.frame methods so that rankings and grouped rankings can be added to model frames.
  • Add format methods for rankings and grouped_rankings, for pretty printing.
  • Add [ methods for rankings and grouped_rankings, to create valid rankings from selected rankings and/or items.
  • Add method argument to offer choices of iterative scaling (default), or direct maximisation of the likelihood via BFGS or L-BFGS.
  • Add itempar method for "PlackettLuce" objects to obtain different parameterizations of the worth parameters.
  • Add read.soc function to read Strict Orders - Complete List (.soc) files from http://www.preflib.org.

Changes in behaviour

Old behaviour should be reproducible with arguments

npseudo = 0, steffensen = 0, start = c(rep(1/N, N), rep(0.1, D))

where N is number of items and D is maximum order of ties.

  • Implement pseudo-data approach - now used by default.
  • Improve starting values for ability parameters
  • Add Steffensen acceleration to iterative scaling algorithm
  • Dropped ref argument from PlackettLuce; should be specified instead when calling coef, summary, vcov or itempar.
  • qvcalc generic now imported from qvcalc

Improvements

  • Refactor code to speed up model fitting and computation of fitted values and vcov.
  • Implement ranking weights and starting values in PlackettLuce.
  • Add package tests
  • Add log argument to coef so that worth parameters (probability of coming first in strict ranking of all items) can be obtained easily.
Assets 2
Loading