Subset a Data Array
This function allows to subset (i.e. slice, take a chunk of) an array, in a
similar way as done in the function
take() in the package plyr. There
are two main inprovements:
The input array can have dimension names, either
names(dim(x)) or in the attribute 'dimensions', and the dimensions to
subset along can be specified via the parameter
along either with
integer indices or either by their name.
There are additional ways to adjust which dimensions are dropped in the
resulting array: either to drop all, to drop none, to drop only the ones that
have been sliced or to drop only the ones that have not been sliced.
If an array is provided without dimension names, dimension names taken from
dim_names will be added to the array.
Subset(x, along, indices, drop = FALSE)
A multidimensional array to be sliced. It can have dimension names either
names(dim(x))or either in the attribute 'dimensions'.
- Vector with references to the dimensions to take the subset from: either integers or dimension names.
- List of indices to take from each dimension specified in 'along'. If a single dimension is specified in 'along' the indices can be directly provided as a single integer or as a vector.
- Whether to drop all the dimensions of length 1 in the resulting array, none, only those that are specified in 'along', or only those that are not specified in 'along'. The possible values are, respectively: 'all' or TRUE, 'none' or FALSE, 'selected', and 'non-selected'.
sample_array <- array(1:24, dim = c(dataset = 1, sdate = 2, member = 3, ftime = 4)) subset <- Subset(sample_array, c('dataset', 'sdate', 'member'), list(1, 1, 1), drop = 'selected')