list2fd.R

list2fd <- function(list, basis){
  if(class(list[[1]]) == "fdSmooth"){
    coef_list <- lapply(list, function(x)x$fd$coefs)
  }else if(class(list[[1]]) == "fd"){
    coef_list <- lapply(list, function(x)x$coefs)
  }
  n_coefs <- unlist(lapply(coef_list, length))

  if(!all(n_coefs == max(n_coefs))) stop()
  
  coef_mat <- matrix(unlist(coef_list), nrow = max(n_coefs))
  out_fd <- fd(coef_mat, basis)
  return(out_fd)
}