library(eyelinkReader)
#> Loading required package: RcppProgress
#> Loading required package: rlang
#> Failed to compile EDF API interface, please read installation instructions.The main function is read_edf() that imports an EDF file
(or throws an error, if EDF API is not installed). By default it will
import all events and attempt to extract standard events: saccades,
blinks, fixations, logged variables, etc.
library(eyelinkReader)
gaze <- read_edf('eyelink-recording.edf')Events and individual event types are stored as tables inside the
eyelinkRecording object with trial column
identifying individual trials. Trial 0 correspond to events (e.g,
DISPLAY_COORDS message, etc.) sent to the eye tracker
before the first trial.
View(gaze$saccades)Working with samples
To import samples, add import_samples = TRUE and,
optionally, specify which sample attributes need to be imported, e.g.,
sample_attributes = c('time', 'gx', 'gy'). All attributes
are imported if sample_attributes is not specified. See
package and EDF API documentation for the full list of attribute
names.
# import samples with all attributes
gaze <- read_edf('eyelink-recording.edf', import_samples = TRUE)
# import samples with selected attributes
gaze <- read_edf('eyelink-recording.edf',
import_samples = TRUE,
sample_attributes = c('time', 'gx', 'gy'))You can convert makes samples cyclopean. In case of a binocular recording, a single column would represent an average between to eyes. E.g., \(gx = (gxL + gxR) / 2\). In case of a monocular recording, a single column will contain information for a recorded eye. This is particularly useful, if you have multiple monocular recordings but some for the right eye and some for the left.
cyclopean_samples <- compute_cyclopean_samples(gaze$samples)Utility functions
The package includes various utility functions that need to be called
separately. For example, to parse non-standard events: recorded areas of
interest (extract_AOIs) and trigger events that help to
time events (extract_triggers).
gaze <- extract_AOIs(gaze)
gaze <- extract_triggers(gaze)or, tidyverse-style
library(tidyverse)
gaze <-
read_edf('eyelink-recording.edf') %>%
extract_AOIs() %>%
extract_triggers()Function adjust_message_time() alters time stamps of
messages that are prefixed by a numeric offset that makes
synchronization easier for e E-Prime / Presentation. I.e., a message
"-50 TARGET_ONSET" that was sent at 105600
becomes a message "TARGET_ONSET" and its time stamp is
105550.
gaze <- adjust_message_time(gaze)