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Frequency of crossing light threshold

Source: R/metric_frequency_crossing_threshold.R
frequency_crossing_threshold.Rd

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. doi:10.1080/09500340.2013.845700

Hartmeyer, S.L., Andersen, M. (2023). Towards a framework for light-dosimetry studies: Quantification metrics. Lighting Research & Technology. 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))
#> # A tibble: 1 × 1
#>   `Frequency crossing 250lx`
#>                        <int>
#> 1                         28

dataset1 %>%
  dplyr::reframe(frequency_crossing_threshold(MEDI, threshold = 250, as.df = TRUE))
#> # A tibble: 1 × 1
#>   frequency_crossing_250
#>                    <int>
#> 1                     28