Returns the first or last parts of a vector, matrix, table, data frame
or function. Since head() and tail() are generic
functions, they may also have been extended to other classes.
Usage
head(x, ...)
"head"(x, n = 6L, ...)
"head"(x, n = 6L, ...)
"head"(x, n = 6L, ...)
"head"(x, n = 6L, ...)
"head"(x, n = 6L, ...)
"head"(x, n = 6L, ...)
tail(x, ...)
"tail"(x, n = 6L, ...)
"tail"(x, n = 6L, ...)
"tail"(x, n = 6L, addrownums = TRUE, ...)
"tail"(x, n = 6L, addrownums = FALSE, ...)
"tail"(x, n = 6L, addrownums = TRUE, ...)
"tail"(x, n = 6L, ...)
Arguments
x
an object
n
a single integer. If positive, size for the resulting
object: number of elements for a vector (including lists), rows for
a matrix or data frame or lines for a function. If negative, all but
the n last/first number of elements of x.
addrownums
if there are no row names, create them from the row
numbers.
...
arguments to be passed to or from other methods.
Value
An object (usually) like x but generally smaller. For
ftable objects x, a transformed format(x).
Details
For matrices, 2-dim tables and data frames, head() (tail()) returns
the first (last) n rows when n > 0 or all but the
last (first) n rows when n < 0. head.matrix() and
tail.matrix() are exported. For functions, the
lines of the deparsed function are returned as character strings.
If a matrix has no row names, then tail() will add row names of
the form "[n,]" to the result, so that it looks similar to the
last lines of x when printed. Setting addrownums =
FALSE suppresses this behaviour.