frequency_crossing_threshold: Frequency of crossing light threshold

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

Frequency of crossing light threshold

Description

This functions calculates the number of times a given threshold light level is crossed.

Usage

frequency_crossing_threshold(
  Light.vector,
  threshold,
  na.rm = FALSE,
  as.df = FALSE
)

Arguments

Light.vector	Numeric vector containing the light data.
threshold	Single numeric value specifying the threshold light level to compare with.
na.rm	Logical. Should missing light values be removed? Defaults to FALSE.
as.df	Logical. Should the output be returned as a data frame? If TRUE, a data frame with a single column named ⁠frequency_crossing_{threshold}⁠ will be returned. Defaults to FALSE.

Value

Data frame or matrix with pairs of threshold and calculated values.

References

Alvarez, A. A., & Wildsoet, C. F. (2013). Quantifying light exposure patterns in young adult students. Journal of Modern Optics, 60(14), 1200–1208. \Sexpr[results=rd]{tools:::Rd_expr_doi("10.1080/09500340.2013.845700")}

Hartmeyer, S.L., Andersen, M. (2023). Towards a framework for light-dosimetry studies: Quantification metrics. Lighting Research & Technology. \Sexpr[results=rd]{tools:::Rd_expr_doi("10.1177/14771535231170500")}

See Also

Other metrics: bright_dark_period(), centroidLE(), disparity_index(), duration_above_threshold(), exponential_moving_average(), interdaily_stability(), intradaily_variability(), midpointCE(), nvRC(), nvRD(), nvRD_cumulative_response(), period_above_threshold(), pulses_above_threshold(), threshold_for_duration(), timing_above_threshold()

Examples

N = 60
dataset1 <-
  tibble::tibble(
    Id = rep("A", N),
    Datetime = lubridate::as_datetime(0) + lubridate::minutes(1:N),
    MEDI = sample(c(sample(1:249, N / 2), sample(250:1000, N / 2))),
  )

dataset1 %>%
  dplyr::reframe("Frequency crossing 250lx" = frequency_crossing_threshold(MEDI, threshold = 250))

dataset1 %>%
  dplyr::reframe(frequency_crossing_threshold(MEDI, threshold = 250, as.df = TRUE))

LightLogR documentation built on April 3, 2025, 10:10 p.m.