[R] regex expression to select row or column

[Junqian Gordon Xu]

I have a multidimensional data which looks like the following:

        "S1-a" "S2-b" "S3-c" "S4-d" "S5-a" "S6-b" "S7-c" "S8-d"
"T1-A"
"T1-B"
"T1-C"
"T1-D"
"T2-A"
"T2-B"
"T2-C"
"T2-D"

I read it from csv file and would like to have 16 separate data frames 
like this

      "S1-a" "S2-a"     "S1-b" "S2-b"     "S1-c" "S2-c"    "S1-d" "S2-d"
"T1-A"            "T1-A"            "T1-A"            "T1-A"
"T2-A"            "T2-A"            "T2-A"            "T2-A"

      "S1-b" "S2-b"   ...
"T1-B"               ...
"T1-B"               ...

...
...

One way is to use loops to cycle through, but I think it's even simpler 
to use regex expression to separate them since "abcd" and "ABCD" are 
unique strings in the table. Does anybody have any pointer on how to do 
this?

Thanks
Gordon