Calculate bootstrap p-values for t statistics

Description

This function takes a numerical matrix and column indexes for two groups to calculate bootstrapped (by re-sampling) p-values comparing the equality of means from the two groups.

Usage

bootstrapT(x, k=20000, obs1, obs2, ...)

Arguments

Value

The result of this function is a numerical matrix with number of rows given by the rows of the argument x and 3 columns. The first column contain the difference of means between the two groups, the second one contain the original t statistic and the last one gives the bootstrapped p-values, for all rows of the matrix x.

Author(s)

Gustavo H. Esteves <gesteves@vision.ime.usp.br>

See Also

t.test from package stats.

Examples

z <- matrix(rnorm(100, 0, 1), 4, 25)
bootstrapT(z, k=100, obs1=1:14, obs2=15:25)

Results

R version 3.3.1 (2016-06-21) -- "Bug in Your Hair"
Copyright (C) 2016 The R Foundation for Statistical Computing
Platform: x86_64-pc-linux-gnu (64-bit)

R is free software and comes with ABSOLUTELY NO WARRANTY.
You are welcome to redistribute it under certain conditions.
Type 'license()' or 'licence()' for distribution details.

R is a collaborative project with many contributors.
Type 'contributors()' for more information and
'citation()' on how to cite R or R packages in publications.

Type 'demo()' for some demos, 'help()' for on-line help, or
'help.start()' for an HTML browser interface to help.
Type 'q()' to quit R.

> library(maigesPack)
Loading required package: convert
Loading required package: Biobase
Loading required package: BiocGenerics
Loading required package: parallel

Attaching package: 'BiocGenerics'

The following objects are masked from 'package:parallel':

    clusterApply, clusterApplyLB, clusterCall, clusterEvalQ,
    clusterExport, clusterMap, parApply, parCapply, parLapply,
    parLapplyLB, parRapply, parSapply, parSapplyLB

The following objects are masked from 'package:stats':

    IQR, mad, xtabs

The following objects are masked from 'package:base':

    Filter, Find, Map, Position, Reduce, anyDuplicated, append,
    as.data.frame, cbind, colnames, do.call, duplicated, eval, evalq,
    get, grep, grepl, intersect, is.unsorted, lapply, lengths, mapply,
    match, mget, order, paste, pmax, pmax.int, pmin, pmin.int, rank,
    rbind, rownames, sapply, setdiff, sort, table, tapply, union,
    unique, unsplit

Welcome to Bioconductor

    Vignettes contain introductory material; view with
    'browseVignettes()'. To cite Bioconductor, see
    'citation("Biobase")', and for packages 'citation("pkgname")'.

Loading required package: limma

Attaching package: 'limma'

The following object is masked from 'package:BiocGenerics':

    plotMA

Loading required package: marray
Loading required package: graph
> png(filename="/home/ddbj/snapshot/RGM3/R_BC/result/maigesPack/bootstrapT.Rd_%03d_medium.png", width=480, height=480)
> ### Name: bootstrapT
> ### Title: Calculate bootstrap p-values for t statistics
> ### Aliases: bootstrapT
> ### Keywords: methods
> 
> ### ** Examples
> 
> z <- matrix(rnorm(100, 0, 1), 4, 25)
> bootstrapT(z, k=100, obs1=1:14, obs2=15:25)
Doing the boots from 1 up to 500
        meanDif  Statistic P.value
[1,] -0.2156558 -0.5143644    0.44
[2,] -0.1289742 -0.2744043    0.78
[3,] -0.1995774 -0.4865079    0.60
[4,]  0.2272298  0.5656571    0.53
> 
> 
> 
> 
> 
> dev.off()
null device 
          1 
>