cantrip to turn a matrix into a data.frame, assuming that the first row of the matrix contains a header row

matrix_to_data.frame.R

matrix_to_df_firstline_header <- function(mat){
  requireNamespace("purrr")
  
  mat %>% 
    ## cut columns into lists
    apply(2, function(s) list(s)) %>% 
    flatten %>% 
    map(flatten_chr) %>% 
    ## set names to the first element of the list
    {set_names(x = map(., ~ .x[-1]),
               nm = map_chr(., 1))} %>% 
    ## create data.frames
    as.data.frame(stringsAsFactors = FALSE)
}