object.
data
(ANY) the variable data, which can be any data object for which
is.rectangular is TRUE,
such as a data.frame, matrix, or atomic vector.
positions
(positions) the x values for the variables, which must be
of type positionsNumeric.
start.position
(positions) the starting x value.
end.position
(positions) the ending x value.
future.positions
(positions) future x values used for predictions.
units
(character) the units for the data.
title
(character) the title of the data set.
documentation
(character) user-supplied documentation.
attributes
(ANY) the attributes slot for arbitrary use.
units.position
(character) the units for the positions slot.