event_term: Create an event model term from a named list of variables.

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

Create an event model term from a named list of variables.

Description

Generates an event_term object which represents the combination of one or more event sequences (e.g., a factor crossed with a numeric modulator). It takes a list of variables (factors, numeric vectors, matrices, basis objects) along with shared onsets, block IDs, and durations. It uses the EV factory internally to create standardized event objects for each variable.

Usage

event_term(evlist, onsets, blockids, durations = 0, subset = NULL)

Arguments

evlist	A named list of variables (factors, numeric, matrices, ParametricBasis objects). The names are used as variable identifiers within the term.
onsets	Numeric vector of onset times (in seconds).
blockids	Numeric vector of block numbers (non-decreasing integers).
durations	Numeric vector of event durations (seconds, default is 0). Can be scalar (recycled) or vector matching length of onsets.
subset	Optional logical vector indicating which events to retain (applied before processing).

Value

A list object with class c("event_term", "event_seq"). Contains:

varname	Concatenated variable names from evlist.
events	A named list of the processed event objects.
subset	The subset vector used.
event_table	A tibble representing the combinations of descriptive levels/names for each event in the term, constructed using elements(..., values=FALSE).
onsets	Numeric vector of onsets (after processing/subsetting).
blockids	Numeric vector of block IDs (after processing/subsetting).
durations	Numeric vector of durations (after processing/subsetting).

Examples

x1 <- factor(rep(letters[1:3], 10))
x2 <- factor(rep(1:3, each = 10))
onsets <- seq(1, 100, length.out = 30)
blockids <- rep(1:3, each = 10)

eterm <- event_term(list(Condition = x1, Group = x2),
                    onsets = onsets,
                    blockids = blockids)
print(eterm)
head(event_table(eterm))
levels(eterm)
head(design_matrix(eterm))

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