seqpack {ff} | R Documentation |
The function seqpack
converts vectors of arbitrary indices into a matrix with row items “from”, “to” and “by”. Sequences within the input vector are automatically detected.
seqpack(x)
x |
a vector containing indices, i.e. integers. |
Extracting a subset of an ff
object results in R to C calls. In order to avoid calling overhead resulting from a sequential processing of the indices, the indices of the subset are analysed and converted by seqpack
. This way, an extraction of arbitrary sequences involves only a single R to C call. This feature is currently only implemented for ff
objects.
A matrix with row items “from”, “to” and “by”. The sub-sequences (and single indices) are given in the column in the same order that they appear in the input.
seqpack(c(1:5,4,1,seq(2,20,4)))