elements: elements

In bbuchsbaum/fmrireg: R package for the anlysis of fmri data

elements

Description

Extract the unique elements from a term or variable in their natural order. For categorical variables (factors), this returns the factor levels. For continuous variables, this returns the unique values in ascending order. For event terms with multiple variables, this returns the combined elements.

Usage

elements(x, ...)

## S3 method for class 'event'
elements(x, what = c("values", "labels"), transformed = TRUE, ...)

## S3 method for class 'event_term'
elements(x, what = c("values", "labels"), ...)

Arguments

x	The term or variable object (typically an event_term, event_factor, or event_variable)
...	Additional arguments passed to methods
what	Character; what to extract - "unique" for unique values or "all" for all values (default: "unique")
transformed	Logical; if TRUE, return transformed values (default: FALSE)

Details

Return the ordered elements of a term or variable.

Value

A vector containing the ordered elements:

• For factors: The factor levels in their defined order

• For numeric variables: Unique values in ascending order

• For event terms: Combined elements from all variables

See Also

levels(), event_term()

Examples

# Create event terms with different types

# Categorical variable
event_data <- data.frame(
  condition = factor(c("A", "B", "A", "B"), levels = c("B", "A")),
  onsets = c(1, 10, 20, 30),
  run = c(1, 1, 1, 1)
)
cat_term <- event_term(
  list(condition = event_data$condition),
  onsets = event_data$onsets,
  blockids = event_data$run
)
elements(cat_term)  # Returns: c("B", "A")

# Continuous variable
event_data$rt <- c(1.2, 0.8, 1.1, 0.9)
cont_term <- event_term(
  list(rt = event_data$rt),
  onsets = event_data$onsets,
  blockids = event_data$run
)
elements(cont_term)  # Returns: c(0.8, 0.9, 1.1, 1.2)

bbuchsbaum/fmrireg documentation built on June 10, 2025, 8:18 p.m.