Double aggregation

Aggregates value twice providing mean of means, SD of SDs, etc.

Usage

aggr2(x, by, fun, ...)

Arguments

x

value to aggregate

by

vector to aggregate by (e.g., ID of participant)

fun

function to apply

...

additional parameters passed to fun

Value

The object returned by fun when applied to the group summaries. Its class depends on fun; scalar numeric summary functions such as base::mean return one numeric value.

Examples

x <- rnorm(100)
id <- rep(1:10, each = 10)

aggregate(x ~ id, FUN = mean)
#>    id          x
#> 1   1  0.2703988
#> 2   2 -0.1530186
#> 3   3  0.1141589
#> 4   4  0.1625241
#> 5   5  0.3340555
#> 6   6  0.0363812
#> 7   7 -0.1121301
#> 8   8  0.5841781
#> 9   9 -0.4975113
#> 10 10  0.4937354
aggr2(x, id, mean)
#> [1] 0.1232772