netfacs: Create probability distribution of combinations of elements...

In NetFACS: Network Applications to Facial Communication Data

Create probability distribution of combinations of elements in the data

Description

The netfacs function underlies most other functions in this package.
It takes the data set and reports the observed and expected probabilities that elements and combinations of elements occur in this data set, and whether this differs from a null condition.

Usage

netfacs(
  data,
  condition = NULL,
  test.condition = NULL,
  null.condition = NULL,
  duration = NULL,
  ran.trials = 1000,
  control = NULL,
  random.level = NULL,
  combination.size = 2,
  tail = "upper.tail",
  use_parallel = TRUE,
  n_cores = 2
)

Arguments

data	A binary matrix with one column per element, and one row per event, consisting of 1 (element was active during that event) and 0 (element was not active).
condition	A character vector the same length as 'data' that contains information on the condition each event belongs to, so probabilities can be compared across conditions; if NULL, all events will be tested against a random null condition based on permutations.
test.condition	A string, indicating the level of 'condition' that is supposed to be tested.
null.condition	A string, indicating the level of 'condition' that is used to create the null distribution of values; if NULL, all levels that are not the test condition will be used.
duration	A numeric vector that contains information on the duration of each event; if NULL, all events are assumed to have equal duration.
ran.trials	Number of randomisations that will be performed to find the null distribution.
control	A list of vectors that are used as control variables. During bootstraps, the ratio of events in each level will be adapted. So, for example, if in the test distribution, there are three angry participants for each happy participant, the null distribution will maintain that ratio.
random.level	A character vector of the level on which the randomization should take place. If NULL, the randomization takes place on the event level (i.e., every row can either be selected or not); if a vector is provided, the randomization takes place on the levels of that vector rather than individual events.
combination.size	A positive integer, indicating the maximum combination size of element combinations. Higher numbers will increase computation time. Default is 2.
tail	Either 'upper.tail' (proportion of null probabilities that are larger than observed probabilities), or 'lower.tail' (proportion of null probabilities that are smaller than observed probabilities); default is 'upper.tail'.
use_parallel	Logical, indicating whether randomization or bootstrap should be parallelized (default is TRUE)
n_cores	Numeric, indicating the number cores to be used for parallelization. Default is 2.

Details

If the 'condition' and 'test.condition' arguments are specified, the null distribution of probability values are based on bootstraps of the null condition. If the 'condition' argument is not specified, the null distribution is based on random permutations of the data.

For a general overview on how to use the netfacs function and package see vignette("netfacs_tutorial").

Value

An object of class netfacs, which contains the probabilities of observing element combinations in the data, along with other useful information. The resulting object is the basis for most other functions in this package.

Author(s)

Alex Mielke, Alan V. Rincon

References

Mielke, A., Waller, B. M., Perez, C., Rincon, A. V., Duboscq, J., & Micheletta, J. (2021). NetFACS: Using network science to understand facial communication systems. Behavior Research Methods. https://doi.org/10.3758/s13428-021-01692-5

See Also

netfacs_multiple, netfacs_extract, conditional_probabilities

Examples

### how do angry facial expressions differ from non-angry ones?

data(emotions_set)
angry.face <- netfacs(
  data = emotions_set[[1]],
  condition = emotions_set[[2]]$emotion,
  test.condition = "anger",
  null.condition = NULL,
  duration = NULL,
  ran.trials = 100,
  control = NULL,
  random.level = NULL,
  combination.size = 5,
  tail = "upper.tail",
  use_parallel = TRUE,
  n_cores = 2
)

head(angry.face$result, 20)
angry.face$event.size.information

NetFACS documentation built on Dec. 7, 2022, 1:12 a.m.