stat_to_pvalue: Convert statistics to p-values
In NESCent/MINOTAUR: MultIvariate visualisatioN and OuTlier Analysis Using R

Description Usage Arguments Details Author(s)

Convert raw statistics to p-values based on fractional ranks. Options are available for one- and two-tailed tests (see details).

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stat_to_pvalue(dfv, column.nums = 1:ncol(dfv), subset = 1:nrow(dfv),
  two.tailed = rep(TRUE, length(column.nums)), right.tailed = rep(FALSE,
  length(column.nums)))

`dfv`	a data frame containing observations in rows and statistics in columns.
`column.nums`	indexes the columns of the data frame that will be used to calculate p-values (all other columns are ignored).
`subset`	index the rows of the data frame that are known contain values from the null distribution. Use all rows if no such information is available.
`two.tailed`	a boolean vector with one entry for each chosen column, where TRUE indicates that the column should be converted to p-values based on a two-tailed test.
`right.tailed`	a boolean vector with one entry for each chosen column, where TRUE indicates that the column should be converted to p-values based on a right-tailed test (see details).

Selected columns in the input data frame are first converted to fractional ranks between 0 and 1 (inclusive). These values are then transformed based on whether a left-tailed, right-tailed or two-tailed p-value is desired (see details). Final values are then transformed again to occupy the range 0-1 exclusive (i.e. between 1/(n+1) and n/(n+1)). If the subset argument is used then ranks are calculated against the chosen subset only, which will lead to several observations having the same p-value.

Each chosen column in the input data frame can be designated as left-tailed, right-tailed or two-tailed independently. The argument two.tailed is a boolean vector where TRUE indicates that the values should be converted to p-values based on a two-tailed test. The argument right.tailed is a boolean vector of the same length as two.tailed, where entries only apply if the corresponding entry of two.tailed is FALSE. For example, the input two.tailed=c(TRUE,FALSE), right.tailed=c(FALSE,FALSE) would produce a two-tailed p-value in the first variable and a left-tailed p-value in the second variable.

Robert Verity r.verity@imperial.ac.uk

NESCent/MINOTAUR documentation built on May 7, 2019, 6:01 p.m.