Convert Absolute Dates and Times to Relative Hours

Convert dates/times to relative times. This function is largely superseded as it is called automatically when data are initialized as a PM_data object. There is rarely a need to call it directly any longer.

Usage

PMmatrixRelTime(
  data,
  idCol = "id",
  dateCol = "date",
  timeCol = "time",
  evidCol = "evid",
  format,
  split = F
)

Arguments

data: The name of an R data object.
idCol: A character vector with the name of the id column in data or the number of the id column, default is “id”
dateCol: A character vector with the name of the date column in data or the number of the date column, default is “date”
timeCol: A character vector with the name of the time column in data or the number of the time column, default is “time”
evidCol: A character vector with the name of the event id column in data or the number of the evid column, default is “evid”
format: Format of the date and time columns; default is m/d/y and h:m:s, as specified in the chron::chron function. Note the separators in each case (/ for dates and : for times). For dates, m is months in digits and can be one or two digits; d is the day of the month, again as one or two digits; y is the year in 2 or 4 digits. For times, all values can be one or two digits, but time is in 24-hour format, and s is required to avoid ambiguity.
split: If true, PMmatrixRelTime will split every id into id.block, where block is defined by a dose reset, or evid=4, e.g. id 1.1, 1.2, 1.3, 2.1, 3.1, 3.2.

Value

Returns a dataframe with columns id, evid, relTime. If split=T all evid values that were previously 4 will be converted to 1.

Details

PMmatrixRelTime will convert absolute dates and times in a dataset into relative hours, suitable for Pmetrics analysis. Additionally, the user has the option to split subjects into pseudosubjects every time a dose reset (evid=4) is encountered.

Author