ave {stats} | R Documentation |

## Group Averages Over Level Combinations of Factors

### Description

Subsets of `x[]`

are averaged, where each subset consist of those
observations with the same factor levels.

### Usage

ave(x, ..., FUN = mean)

### Arguments

`x` |
A numeric. |

`...` |
Grouping variables, typically factors, all of the same
`length` as `x` . |

`FUN` |
Function to apply for each factor level combination. |

### Value

A numeric vector, say `y`

of length `length(x)`

.
If `...`

is `g1,g2`

, e.g.,
`y[i]`

is equal to `FUN(x[j]`

, for all `j`

with
`g1[j] == g1[i]`

and `g2[j] == g2[i])`

.

### See Also

`mean`

, `median`

.

### Examples

ave(1:3)# no grouping -> grand mean
attach(warpbreaks)
ave(breaks, wool)
ave(breaks, tension)
ave(breaks, tension, FUN = function(x)mean(x, trim=.1))
plot(breaks, main =
"ave( Warpbreaks ) for wool x tension combinations")
lines(ave(breaks, wool, tension ), type='s', col = "blue")
lines(ave(breaks, wool, tension, FUN=median), type='s', col = "green")
legend(40,70, c("mean","median"), lty=1,col=c("blue","green"), bg="gray90")
detach()

[Package

*stats* version 2.5.0

Index]