poolSDTransform is a transformations that can
be applied to a matrix of data. The resulting matrix has the column-
standard deviations equal to the pool standard deviations of the
individual columns, the solution adopted by (Loftus and Masson 1994)
.
poolSDTransform(dta, variables)a data.frame containing the data in wide format;
a vector of column names on which the transformation will be applied. the remaining columns will be left unchanged
a data.frame of the same form as dta with the variables transformed.
This function is useful when passed to the argument preprocessfct of superbPlot()
where it performs a modification of the data matrix.
Loftus GR, Masson MEJ (1994). “Using confidence intervals in within-subject designs.” Psychonomic Bulletin & Review, 1, 476 -- 490. doi:10.3758/BF03210951 .