📅  最后修改于: 2022-03-11 14:51:57.765000             🧑  作者: Mango
outer( c("aa", "ab", "cc"), c("aa", "ab", "cc") , "paste" )
vals <- c( c("aa", "ab", "cc"), c("aa", "ab", "cc") )
vals <- unique( vals )
combn( vals , 2 )