我有一个像下面这样的数据框, dat<- structure(list(Octagonplot = c(11, 12, 13, 14, 21, 22, 23, 24, 31, 32, 33, 34, 41, 42, 43, 44, 51, 52, 53, 54, 61, 62, 63, 64, 71, 72, 73, 74, 81, 82, 83, 84, 91, 92, 93, 94, 101, 102, 103, 104, 111, 112, 113, 114, 121, 122, 123, 124, 11, 12, 13, 14, 21, 22, 23, 24, 31, 32,