Apply line-broadening (apodisation) to MRS data or basis object.
lb(x, lb, lg = 1)
# S3 method for class 'list'
lb(x, lb, lg = 1)
# S3 method for class 'mrs_data'
lb(x, lb, lg = 1)
# S3 method for class 'basis_set'
lb(x, lb, lg = 1)
line-broadened data.