mcroast: Multiple Contrast Rotation Tests

Description Usage Arguments Details Value Author(s) References Examples

Description

Adaption of the roast function in package limma to perform a maxT-test in the multivariate linear model, controlling FWER for multiple contrasts.

Usage

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mcroast(formula, data = NULL, K, nrot = 9999, adjusted = TRUE, moderated = FALSE)

Arguments

formula

A formula object, analogously to lm, with a matrix of response variables (independent subjects in rows) on the left, and design covariates on the right hand side.

data

A data.frame object, searching for column names in formula.

K

A contrast matrix (different contrasts in rows), with the same number of columns as number of parameters in the model

nrot

Number of Monte Carlo simulation steps

adjusted

logical, if TRUE single-step maxT FWER control is performed; if FALSE the comparison-wise error rate is controlled

moderated

logical, if TRUE, moderated statistics (Smyth 2004) are used.

Details

Most of the code was taken from function roast in package limma (Bioconductor).

Value

A list with

Y

The matrix of response variables

X

The design matrix

statistic

A matrix of test statistics

pvalue

A matrix of (adjusted) p-values

B

A matrix with contrast parameter estimates

SD

A matrix with estimated standard deviations

mrot

A vector with simulated maxT statistics under H0

Author(s)

Daniel Gerhard

References

Wu, D, Lim, E, Francois Vaillant, F, Asselin-Labat, M-L, Visvader, JE, and Smyth, GK (2010). ROAST: rotation gene set tests for complex microarray experiments. Bioinformatics 26, 2176-2182.

Langsrud, O (2005). Rotation tests. Statistics and Computing 15, 53-60.

Examples

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### data example from Hasler & Hothorn (2011), 
### A Dunnett-Type Procedure for Multiple Endpoints,
### The International Journal of Biostatistics: Vol. 7: Iss. 1, Article 3.
### DOI: 10.2202/1557-4679.1258
# but using two-sided inference

### see ?coagulation
data("coagulation", package = "SimComp")

### Dunnett contrast for comparisons to a control
K <- multcomp::contrMat(table(coagulation$Group), type="Dunnett")

### Rotation test with FWER control
(mcr <- mcroast(cbind(Thromb.count, ADP, TRAP) ~ Group-1, data=coagulation, K=K))
mcr$pvalue

### Simultaneous confidence intervals
confint(mcr)

daniel-gerhard/mcroast documentation built on May 14, 2019, 3:38 p.m.