baseline_model: Construct a Baseline Model

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

Construct a Baseline Model

Description

Builds a baseline model to account for noise and non–event-related variance. This model may include a drift term, a block intercept term, and nuisance regressors.

Usage

baseline_model(
  basis = c("constant", "poly", "bs", "ns"),
  degree = 1,
  sframe,
  intercept = c("runwise", "global", "none"),
  nuisance_list = NULL
)

Arguments

basis	Character; type of basis function ("constant", "poly", "bs", or "ns").
degree	Integer; degree of the spline/polynomial function.
sframe	A sampling_frame object.
intercept	Character; whether to include an intercept ("runwise", "global", or "none"). Ignored when basis == "constant" because the drift term already provides the constant baseline.
nuisance_list	Optional list of nuisance matrices (one matrix per fMRI block).

Value

An object of class "baseline_model".

Examples

sframe <- fmrihrf::sampling_frame(blocklens = c(100, 100), TR = 2)
bmod <- baseline_model(basis = "bs", degree = 3, sframe = sframe)
bmod_global <- baseline_model(basis = "bs", degree = 3, sframe = sframe, intercept = "global")
bmod_nointercept <- baseline_model(basis = "bs", degree = 3, sframe = sframe, intercept = "none")
stopifnot(ncol(design_matrix(bmod)) == 8)

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