Returns the upper left or lower right part of a
spam object.
Usage
head(x, ...)
tail(x, ...)
# head.spam(x, n = 6L, m = n, ...)
# tail.spam(x, n = 6L, m = n, addrownums = TRUE, ...)
Arguments
x
a spam 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
m
similar to n but for the number of columns.
addrownums
create row and column namves them from the selected
elements.
...
arguments to be passed to or from other methods.
Value
An regular matrix.
Details
For matrices, 2-dim tables and data frames, head() (tail()) returns
the first (last) n rows and m columns when n > 0 or all but the
last (first) n rows when n < 0 (with similar behavior
for m).
tail() will add row and column names of
the form "[n,]" and "[,n]" to the result, so that it looks similar to the
last lines and columns of x when printed. Setting addrownums =
FALSE suppresses this behaviour.
A method for spam.chol.NgPeyton objects is
exported as well.