x
is an object with a dim
attribute (e.g., a matrix or array
), then drop
returns an object like x
, but with any extents of length one removed. Any accompanying dimnames
attribute is adjusted and returned with x
: if the result is a vector the names
are taken from the dimnames
(if any). If the result is a length-one vector, the names are taken from the first dimension with a dimname.[
) performs this reduction unless used with drop = FALSE
, but sometimes it is useful to invoke drop
directly.drop1
which is used for dropping terms in models.library(base)
# NOT RUN {dim(drop(array(1:12, dim = c(1,3,1,1,2,1,2)))) # = 3 2 2drop(1:3 %*% 2:4) # scalar product# }