Changes in results

  • hoa() now computes the modified likelihood root correctly for contrasts with more than one nonzero coefficient, such as averages, trends or Tukey-type comparisons in models with correlated coefficients. Previously the nuisance information was taken from a sub-block of the covariance matrix, which is only correct for contrasts that select a single coefficient. Adjusted statistics, intervals and p-values change for such contrasts, in some cases by as much as the whole higher-order correction. Pairwise contrasts in cell-means models (for example the Dunnett example in the vignette) were nearly unaffected.

  • hoa() also uses the working weights at the final constrained fit, which changes its results slightly (up to about 1e-4) for all contrasts.

  • hoa() no longer discards every profile point for larger data sets.

Bug fixes

  • plot() failed for intervals from confint(..., alternative = "less").

  • expit() is now an exported generic, so expit(confint(...)) transforms intervals to the probability scale as documented.

  • mcprofile() failed when all grid points lay on one side of the estimate.

  • mcprofile() for lm objects failed when the data, weights or formula were defined inside a function, or when the data had the same name as an argument of mcprofile() (for example CM).

  • confint() now checks adjust and alternative. A misspelled alternative previously gave a confusing error, or could silently return an unrelated object called ci from the workspace as the intervals. Unambiguous abbreviations such as alternative = "g" are now accepted.

  • mcprofile() now gives a clear error for models with aliased (NA) coefficients, and for a contrast matrix with the wrong number of columns.

Other changes

  • Profiling is faster: each constrained fit solves the quadratic program once per iteration, and the starting values on each side of the estimate are chosen better.

  • Requires ggplot2 3.4.0 or later. plot() for intervals no longer uses the deprecated geom_errorbarh().

  • The citation uses bibentry().

  • Added a test suite.