emmeans: pwpm – R documentation

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pwpm

Pairwise P-value matrix (plus other statistics)

Description

This function presents results from emmeans and pairwise comparisons thereof in a compact way. It displays a matrix (or matrices) of estimates, pairwise differences, and P values. The user may opt to exclude any of these via arguments means, diffs, and pvals, respectively. To control the direction of the pairwise differences, use reverse; and to control what appears in the upper and lower triangle(s), use flip. Optional arguments are passed to contrast.emmGrid and/or summary.emmGrid, making it possible to control what estimates and tests are displayed.

Usage

pwpm(emm, by, reverse = FALSE, pvals = TRUE, means = TRUE,
  diffs = TRUE, flip = FALSE, digits, ...)

Arguments

`emm`	An `emmGrid` object
`by`	Character vector of variable(s) in the grid to condition on. These will create different matrices, one for each level or level-combination. If missing, `by` is set to `emm@misc$by.vars`. Grid factors not in `by` are the primary factors: whose levels or level combinations are compared pairwise.
`reverse`	Logical value passed to `pairs.emmGrid`. Thus, `FALSE` specifies `"pairwise"` comparisons (earlier vs. later), and `TRUE` specifies `"revpairwise"` comparisons (later vs. earlier).
`pvals`	Logical value. If `TRUE`, the pairwise differences of the EMMs are included in each matrix according to `flip`.
`means`	Logical value. If `TRUE`, the estimated marginal means (EMMs) from `emm` are included in the matrix diagonal(s).
`diffs`	Logical value. If `TRUE`, the pairwise differences of the EMMs are included in each matrix according to `flip`.
`flip`	Logical value that determines where P values and differences are placed. `FALSE` places the P values in the upper triangle and differences in the lower, and `TRUE` does just the opposite.
`digits`	Integer. Number of digits to display. If missing, an optimal number of digits is determined.
`...`	Additional arguments passed to `contrast.emmGrid` and `summary.emmGrid`. You should not include `method` here, because pairwise comparisons are always used.

Value

A matrix or 'list' of matrices, one for each 'by' level.

Examples

warp.lm <- lm(breaks ~ wool * tension, data = warpbreaks)
warp.emm <- emmeans(warp.lm, ~ tension | wool)

pwpm(warp.emm)

# use dot options to specify noninferiority tests
pwpm(warp.emm, by = NULL, side = ">", delta = 5, adjust = "none")

emmeans

Estimated Marginal Means, aka Least-Squares Means

v1.6.0

GPL-2 | GPL-3

Authors

Russell V. Lenth [aut, cre, cph], Paul Buerkner [ctb], Maxime Herve [ctb], Jonathon Love [ctb], Hannes Riebl [ctb], Henrik Singmann [ctb]

Initial release

2021-04-25