Return types

[wilsonfreitas]

execute function should receive a parameter which specifies its return type.
It should work pretty much like vapply's FUN.VALUE argument.

> i39 <- sapply(3:9, seq)
> i39
[[1]]
[1] 1 2 3

[[2]]
[1] 1 2 3 4

[[3]]
[1] 1 2 3 4 5

[[4]]
[1] 1 2 3 4 5 6

[[5]]
[1] 1 2 3 4 5 6 7

[[6]]
[1] 1 2 3 4 5 6 7 8

[[7]]
[1] 1 2 3 4 5 6 7 8 9

> vapply(i39, fivenum,
+        c(Min. = 0, "1st Qu." = 0, Median = 0, "3rd Qu." = 0, Max. = 0))
        [,1] [,2] [,3] [,4] [,5] [,6] [,7]
Min.     1.0  1.0    1  1.0  1.0  1.0    1
1st Qu.  1.5  1.5    2  2.0  2.5  2.5    3
Median   2.0  2.5    3  3.5  4.0  4.5    5
3rd Qu.  2.5  3.5    4  5.0  5.5  6.5    7
Max.     3.0  4.0    5  6.0  7.0  8.0    9

It obviously can be extended to xts, data.frame and other types.