getContrasts: Read and format contrast tables from Excel
In dmenne/dmisc2: Dieter Menne's Misc Functions

Description Usage Arguments Value Author(s) See Also Examples

Reads contrast from an Excel file for use with estimable of package gmodels.

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getContrasts(cname, excelfile, rows = NULL)

readContrasts(cname, excelfile)

`cname`	Sheet name in Excel file
`excelfile`	path of Excel file with contrast table
`rows`	optionally only select some rows of the table

readContrasts read a contrast table. Only columns with at least on period in the header are kept. getContrasts additionally includes column and row name information to label contrast tables with estimable (gmodels)

Dieter Menne, dieter.menne@menne-biomed.de

See constrast.xlsx in the extdata directory for some rules of thumb on constructing a contrast matrix.

library(nlme)
library(gmodels)
options(digits=3)
set.seed(4711)
excelfile = system.file("extdata", "contrasts.xlsx", package = "Dmisc2")
d = expand.grid(subject = LETTERS[1:8],
                peri= c("Wine", "Tea"),
                post = c("Water", "Kirsch"),
                interval = c("Pre", "Post"))
d$vol = round(rnorm(nrow(d),10,2),1)
d.lme = lme(vol~interval+peri+post+peri:interval+interval:post,
            data=d,random=~1|subject)
summary(d.lme)
ct = getContrasts("peripostinterval",excelfile)
estimable(d.lme,ct,conf.int=0.95)