Get HRF by Name

Retrieves an HRF by name from the registry and optionally applies decorators. This provides a unified interface for creating both pre-defined HRF objects and custom basis sets with specified parameters.

Usage

getHRF(
  name = "spmg1",
  nbasis = 5,
  span = 24,
  lag = 0,
  width = 0,
  summate = TRUE,
  normalize = FALSE,
  ...
)

Arguments

name

Character string specifying the HRF type. Options include:

• "spmg1", "spmg2", "spmg3" - SPM canonical HRFs

• "gamma", "gaussian" - Simple parametric HRFs

• "fir" - Finite Impulse Response basis

• "bspline" or "bs" - B-spline basis

• "fourier" - Fourier basis

• "daguerre" - Daguerre spherical basis

• "tent" - Tent (linear spline) basis

nbasis

Number of basis functions (for basis set types)

span

Temporal window in seconds (default: 24)

lag

Time lag in seconds to apply (default: 0)

width

Block width for block designs (default: 0)

summate

Whether to sum responses in block designs (default: TRUE)

normalize

Whether to normalize the HRF (default: FALSE)

...

Additional arguments passed to generator functions (e.g., scale for daguerre)

Value

An HRF object

Details

For single HRF types (spmg1, gamma, gaussian), the function returns pre-defined objects. For basis set types (fir, bspline, fourier, daguerre), it calls the appropriate generator function with the specified parameters.

Examples

# Get pre-defined canonical HRF
canonical <- getHRF("spmg1")

# Create custom FIR basis with 20 bins
fir20 <- getHRF("fir", nbasis = 20, span = 30)

# Create B-spline basis with lag
bs_lag <- getHRF("bspline", nbasis = 8, lag = 2)

# Create blocked Gaussian HRF
block_gauss <- getHRF("gaussian", width = 5)