add_duration()
approximates the time spent on a visit based on the difference
between two consecutive timestamps, replacing differences exceeding cutoff
with
the value defined in replace_by
.
Usage
add_duration(
wt,
cutoff = 300,
replace_by = NA,
last_replace_by = NA,
device_switch_na = FALSE,
device_var = NULL
)
Arguments
- wt
webtrack data object.
- cutoff
numeric (seconds). If duration is greater than this value, it is reset to the value defined by
replace_by
. Defaults to 300 seconds.- replace_by
numeric. Determines whether differences greater than the cutoff are set to
NA
, or some value. Defaults toNA
.- last_replace_by
numeric. Determines whether the last visit for an individual is set to
NA
, or some value. Defaults toNA
.- device_switch_na
boolean. Relevant only when data was collected from multiple devices. When visits are ordered by timestamp sequence, two consecutive visits can come from different devices, which makes the timestamp difference less likely to be the true duration. It may be preferable to set the duration of the visit to
NA
(TRUE
) rather than the difference to the next timestamp (FALSE
). Defaults toFALSE
.- device_var
character. Column indicating device. Required if 'device_switch_na' set to
TRUE
. Defaults toNULL
.
Examples
if (FALSE) { # \dontrun{
data("testdt_tracking")
wt <- as.wt_dt(testdt_tracking)
wt <- add_duration(wt)
# Defining cutoff at 10 minutes, replacing those exceeding cutoff to 5 minutes,
# and setting duration before device switch to `NA`:
wt <- add_duration(wt,
cutoff = 600, replace_by = 300,
device_switch_na = TRUE, device_var = "device"
)
} # }