applyXPtr: Apply facility for objects of class XPtr
In rrp: Random Recursive Partitioning

Description Usage Arguments Details Value Author(s) References See Also Examples

This tool function allow to apply a function along some index and on a subset of elements of the XPtr object. Is the counterpart of apply for objects fo class matrix.

1	applyXPtr(d, idx, sub, f)

`d`	an object of class `XPtr`
`idx`	a vector of integers, the indexes of the apply
`sub`	a vector of integers, the indexes of the subest
`f`	a function to be evaluated in the `.GlobalEnv`

The object d is like a dist object, which is one-dimensional but usually associated to a symmetrix matrix M with 0's on the diagonal. This function allows to apply a function f on d as if it was applied this way on the matrix M: apply(M[idx,sub],1,f).

val

an invisible object of type list

S.M. Iacus

Iacus, S.M., Porro, G. (2009) Random Recursive Partitioning: a matching method for the estimation of the average treatment effect, Journal of Applied Econometrics, 24, 163-185.

Iacus, S.M., Porro, G. (2007) Missing data imputation, matching and other applications of random recursive partitioning, Computational Statistics and Data Analysis, 52, 2, 773-789.

newXPtr

a <- newXPtr(10,1)
addXPtr(a, list(c(1,3,4,9), c(2,5), c(1,7,9)), c(-1, 5, 10))
f <- function(x) sum(x)
idx <- 1:5
sub <- 7:10
applyXPtr(a, idx, sub, f) -> l
(XPtrToDist(a))
l