uniques: Unique Values for Subject, Timepoint and Result

In Transition: Characterise Transitions in Test Result Status in Longitudinal Studies

Unique Values for Subject, Timepoint and Result

Description

uniques() identifies unique values for subjects, timepoints and test results in longitudinal study data.

Usage

uniques(
  object,
  subject = "subject",
  timepoint = "timepoint",
  result = "result"
)

Arguments

object	a data.frame (or object coercible by as.data.frame() to a data frame) containing the data to be analysed.
subject	character, name of the column (of type integer or factor) identifying individual study subjects; default "subject".
timepoint	character, name of the column recording time points (as Dates) of testing of subjects; default "timepoint".
result	character, name of the column (of type ordered factor, or binary, see Details) recording test results; default "result".

Details

See Transitions details.

Works for subject as either an integer vector or a factor.

Value

A list of three elements

1.	An integer vector or factor of unique subject identifications.
2.	A vector of class Date of unique timepoints in the study.
3.	An ordered factor of unique values for results of the study.

See Also

data.frame, Dates, ordered factor.

Other transitions: PreviousDate, PreviousResult, Transitions

Examples

 ## Continuing example from `add_transitions()`
  # subject, timepoint and result arguments all defaults and required types
  # (native subject is factor)
uniques(Blackmore)
  #
Blackmore <- transform(Blackmore, subject = as.integer(subject))
  # subject now as integer
Blackmore |> str()
uniques(Blackmore)

rm(Blackmore)

Transition documentation built on Feb. 11, 2026, 5:07 p.m.