Number of basis functions

Return the number of basis functions represented by an object.

Usage

nbasis(x, ...)

# S3 method for class 'HRF'
nbasis(x, ...)

# S3 method for class 'Reg'
nbasis(x, ...)

Arguments

x

Object containing HRF or regressor information.

...

Additional arguments passed to methods.

Value

Integer scalar giving the number of basis functions.

Details

This information is typically used when constructing penalty matrices or understanding the complexity of an HRF model or regressor.

Examples

# Number of basis functions for different HRF types
nbasis(HRF_SPMG1)   # 1 basis function
#> [1] 1
nbasis(HRF_SPMG3)   # 3 basis functions (canonical + 2 derivatives)
#> [1] 3
nbasis(HRF_BSPLINE) # 5 basis functions (default)
#> [1] 5

# For a regressor
reg <- regressor(onsets = c(10, 30, 50), hrf = HRF_SPMG3)
nbasis(reg)  # 3 (inherits from the HRF)
#> [1] 3