rowFtests {arrayMagic}R Documentation

F-test and t-test for rows of a matrix

Description

F-test and t-test for rows of a matrix

Usage

rowFtests(x, fac)
rowttests(x, fac)

Arguments

x Matrix
fac Factor, with length(fac)=ncol(x). For rowttests, fac must have exactly two levels.

Details

If fac is specified, rowttests performs for each row of x a two-sided, two-class t-test with equal variances. fac must be a factor of length ncol(x) with two levels, corresponding to the two groups.

If fac is missing, rowttests performs for each row of x a two-sided one-class t-test against the null hypothesis 'mean=0'.

With the current implementation, NAs are not allowed. This could be changed if desirable.

Value

A list with the test statistics, p-values, degrees of freedom.

Author(s)

Wolfgang Huber <w.huber@dkfz.de>

See Also

mt.teststat

Examples

   x  = matrix(runif(9700), ncol=97)
   k2 = floor(runif(ncol(x))*2)
   k7 = floor(runif(ncol(x))*7)

   t1 = rowttests(x)
   t2 = rowttests(x, factor(k2))
   ft = rowFtests(x, factor(k7))

   if(require(multtest)) {
     fs = mt.teststat(x, k7, test="f")
     stopifnot(all(abs(fs - ft$statistic) < 1e-6))

     ts2 = mt.teststat(x, k2, test="t.equalvar")
     stopifnot(all(abs(ts2 - t2$statistic) < 1e-6))

     ts1 = apply(x, 1, function(x) t.test(x)$statistic)
     stopifnot(all(abs(ts1 - t1$statistic) < 1e-6))
   }

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