Create FIR HRF Basis Set

Generates an HRF object using Finite Impulse Response (FIR) basis functions with custom parameters. Each basis function represents a time bin with a value of 1 in that bin and 0 elsewhere.

Usage

hrf_fir_generator(nbasis = 12, span = 24)

Arguments

nbasis

Number of time bins (default: 12)

span

Temporal window in seconds (default: 24)

Value

An HRF object of class c("FIR_HRF", "HRF", "function")

Details

The FIR basis divides the time window into nbasis equal bins. Each basis function is an indicator function for its corresponding bin. This provides maximum flexibility but requires more parameters than smoother basis sets like B-splines.

See also

HRF_objects for pre-defined HRF objects, getHRF for a unified interface to create HRFs, hrf_bspline_generator for a smoother alternative

Examples

# Create FIR basis with 20 bins over 30 seconds
custom_fir <- hrf_fir_generator(nbasis = 20, span = 30)
t <- seq(0, 30, by = 0.1)
response <- evaluate(custom_fir, t)
matplot(t, response, type = "l", main = "FIR HRF with 20 time bins")


# Compare to default FIR with 12 bins
default_fir <- HRF_FIR
response_default <- evaluate(default_fir, t[1:241])  # 24 seconds
matplot(t[1:241], response_default, type = "l", 
        main = "Default FIR HRF (12 bins over 24s)")