Sets or retrieves the "units"
attribute of an object.
For units.default
replaces the builtin
version, which only works for time series objects. If the variable is
also given a label
, subsetting (using [.labelled
) will
retain the "units"
attribute. For a Surv
object,
units
first looks for an overall "units"
attribute, then
it looks for units
for the time2
variable then for time1
.
When setting "units"
, value
is changed to lower case and any "s" at
the end is removed.
units(x, ...)
# S3 method for default
units(x, none='', ...)
# S3 method for Surv
units(x, none='', ...)
# S3 method for default
units(x) <- value
the units attribute of x, if any; otherwise, the units
attribute of
the tspar
attribute of x
if any; otherwise the value
none
. Handling for Surv
objects is different (see above).
any object
ignored
the units of the object, or ""
value to which to set result if no appropriate attribute is found
label
require(survival)
fail.time <- c(10,20)
units(fail.time) <- "Day"
describe(fail.time)
S <- Surv(fail.time)
units(S)
label(fail.time) <- 'Failure Time'
units(fail.time) <- 'Days'
fail.time
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