get the position of an index of tensor — toPos.tensor • tensorA

Calculates the position of a tensor index, which specified in any possible way.

toPos.tensor(M,l=NULL,mnames=names(dim(M)),by=NULL,...,both=FALSE,missing.ok=FALSE)

Arguments

M: a tensor
l: a vector specifying the indices as positions or names
mnames: The names of the indices of the tensor. This can be specified instead of M.
both: Matches the index in its covariate and contravariate form.
by: the list dimension, all operations are done in parallel for all levels of these dimensions. Thus in the case of toPos all other dimensions are returned if they are not specified.
...: not used
missing.ok: If TRUE does give an error on missing dimension. Rather returns NA in that place.

Value

a numeric vector giving the positions of the dimensions selected.

Details

The function is only here to provide a consistent interface which provides the same functionality for positions and characters.

Author

K. Gerald van den Boogaart

Examples

A <- to.tensor(1:30,c(a=2,b=3,c=5))
toPos.tensor(A,c("b","c"))
#> [1] 2 3
toPos.tensor(A,c(2,1))     # only returns the values
#> [1] 2 1
toPos.tensor(A,c("^a"),both=TRUE)
#> [1] 1