These functions extract a designated subset of a hyperframe,
or replace the designated subset with another hyperframe.
The function [.hyperframe is a method for the subset operator
[ for the
class "hyperframe". It extracts the subset of x
specified by the row index i and column index j.
The argument drop determines whether the array structure
will be discarded if possible. The argument strip determines
whether the list structure in a row or column or cell will be discarded if
possible.
If drop=FALSE (the default), the return value is always
a hyperframe or data frame.
If drop=TRUE, and if the selected subset has only one row,
or only one column, or both, then
The function [<-.hyperframe is a method for the
subset replacement operator [<- for the
class "hyperframe". It replaces the designated
subset with the hyperframe value.
The subset of x to be replaced is designated by
the arguments i and j as above.
The replacement value should be a hyperframe with the
appropriate dimensions, or (if the specified subset is a single
column) a list of the appropriate length.
The function $.hyperframe is a method for $
for hyperframes. It extracts the relevant column of the hyperframe.
The result is always a list (i.e. equivalent to using
[.hyperframe with strip=FALSE).
The function $<-.hyperframe is a method for $<-
for hyperframes. It replaces the relevant column of the hyperframe.
The replacement value should be a list of the appropriate length.
The functions [[.hyperframe and [[<-.hyperframe
are methods for [[ and [[<-.hyperframe
for hyperframes. They are analogous to [[.data.frame
and [[<-.data.frame in that they can be used in different ways:
when [[.hyperframe or [[<-.hyperframe
are used with a single index,
as in x[[n]] or x[[n]] <- value,
they index the hyperframe as if it were a list,
extracting or replacing a column of the hyperframe.
when [[.hyperframe or [[<-.hyperframe
are used with two indices,
as in x[[i,j]] or x[[i,j]] <- value,
they index the hyperframe as if it were a
matrix, and can only be used to extract or replace one element.