drop                  package:base                  R Documentation

Drop Redundant Extent Information

Description:

     Delete the dimensions of an array which have only one level.

Usage:

     drop(x)

Arguments:

       x: an array (including a matrix).

Value:

     If `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'.

     Array subsetting (`[') performs this reduction unless used with
     `drop = FALSE', but sometimes it is useful to invoke `drop'
     directly.

See Also:

     `drop1' which is used for dropping terms in models.

Examples:

     dim(drop(array(1:12, dim=c(1,3,1,1,2,1,2))))# = 3 2 2
     drop(1:3 %*% 2:4)# scalar product

