aggregate_Datetime: Aggregate Datetime data

In LightLogR: Process Data from Wearable Light Loggers and Optical Radiation Dosimeters

Aggregate Datetime data

Description

Condenses a dataset by aggregating the data to a given (shorter) interval unit. aggregate_Datetime() is opinionated in the sense that it sets default handlers for each data type of numeric, character, logical, factor, duration, time, and datetime. These can be overwritten by the user. Columns that do not fall into one of these categories need to be handled individually by the user (... argument) or will be removed during aggregation. If no unit is specified the data will simply be aggregated to the most common interval (dominant.epoch), which is most often not an aggregation but a rounding.)

Usage

aggregate_Datetime(
  dataset,
  unit = "dominant.epoch",
  Datetime.colname = Datetime,
  type = c("round", "floor", "ceiling"),
  numeric.handler = mean,
  character.handler = function(x) names(which.max(table(x, useNA = "ifany"))),
  logical.handler = function(x) mean(x) >= 0.5,
  factor.handler = function(x) factor(names(which.max(table(x, useNA = "ifany")))),
  datetime.handler = mean,
  duration.handler = function(x) lubridate::duration(mean(x)),
  time.handler = function(x) hms::as_hms(mean(x)),
  ...
)

Arguments

dataset	A light logger dataset. Expects a dataframe. If not imported by LightLogR, take care to choose a sensible variable for the Datetime.colname.
unit	Unit of binning. See lubridate::round_date() for examples. The default is "dominant.epoch", which means everything will be aggregated to the most common interval. This is especially useful for slightly irregular data, but can be computationally expensive. "none" will not aggregate the data at all.
Datetime.colname	column name that contains the datetime. Defaults to "Datetime" which is automatically correct for data imported with LightLogR. Expects a symbol. Needs to be part of the dataset. Must be of type POSIXct.
type	One of "round"(the default), "ceiling" or "floor". Setting chooses the relevant function from lubridate.
numeric.handler, character.handler, logical.handler, factor.handler, datetime.handler, duration.handler, time.handler	functions that handle the respective data types. The default handlers calculate the mean or median for numeric, POSIXct, duration, and hms, and the mode for character, factor and logical types.
...	arguments given over to dplyr::summarize() to handle columns that do not fall into one of the categories above.

Details

Summary values for type POSIXct are calculated as the mean, which can be nonsensical at times (e.g., the mean of Day1 18:00 and Day2 18:00, is Day2 6:00, which can be the desired result, but if the focus is on time, rather then on datetime, it is recommended that values are converted to times via hms::as_hms() before applying the function (the mean of 18:00 and 18:00 is still 18:00, not 6:00).

Value

A tibble with aggregated Datetime data. Usually the number of rows will be smaller than the input dataset. If the handler arguments capture all column types, the number of columns will be the same as in the input dataset.

Examples

#dominant epoch without aggregation
sample.data.environment %>%
 dominant_epoch()

#dominant epoch with 5 minute aggregation
sample.data.environment %>%
 aggregate_Datetime(unit = "5 mins") %>%
 dominant_epoch()

#dominant epoch with 1 day aggregation
sample.data.environment %>%
 aggregate_Datetime(unit = "1 day") %>%
 dominant_epoch()

LightLogR documentation built on June 10, 2025, 5:12 p.m.