# A simple function to compute a permutation t-test.

### Description

The data matrix, `x`

, with two-level factor, `fac`

, is used
to compute t-tests. The values of `fac`

are permuted `B`

times and the complete set of t-tests is performed for each
permutation.

### Usage

1 |

### Arguments

`x` |
A data matrix. The number of columns should be the same as
the length of |

`fac` |
A factor with two levels. |

`B` |
An integer specifying the number of permutations. |

`tsO` |
A logical indicating whether to compute only the t-test
statistic for each permuation. If |

### Details

Not much more to say. Probably there is a generic function somewhere, but I could not find it.

### Value

A list, the first element is named `obs`

and contains the true,
observed, values of the t-statistic. The second element is named
`ans`

and contains a list of length `B`

containing the
different permuations.

### Author(s)

R. Gentleman

### See Also

`rowttests`

### Examples

1 2 3 |