直接用paste函数 fileslss1<-paste0(1:6,"/out/rho",1:20,".dat")  结果是
[1] "1/out/rho1.dat"  "2/out/rho2.dat"  "3/out/rho3.dat"  "4/out/rho4.dat"  "5/out/rho5.dat"  "6/out/rho6.dat"  "1/out/rho7.dat"  "2/out/rho8.dat"
[9] "3/out/rho9.dat"  "4/out/rho10.dat" "5/out/rho11.dat" "6/out/rho12.dat" "1/out/rho13.dat" "2/out/rho14.dat" "3/out/rho15.dat" "4/out/rho16.dat"
[17] "5/out/rho17.dat" "6/out/rho18.dat" "1/out/rho19.dat" "2/out/rho20.dat"
说明直接用paste只能是向量的补全组合，而现在要的结果是1:6中的每一个元素都跟后面向量中的元素组合一次，输出6x20个字符串，有谁知道怎么办？