Convert nwk to CFMatrix
nwk2cf(nwk, filename = "test.CFMatrix")
a dataframe and a file
nwk_text="((((((((((8)7,(1)12)9)10)2)4)3,5,(((17)11)16)14)15)6)13)18;"
nwk2cf(nwk=nwk_text)
#> Error in `$<-.data.frame`(`*tmp*`, "label", value = character(0)): replacement has 0 rows, data has 7