[R] regex expression to select row or column

[Junqian Gordon Xu]

You're right. Using read.csv, the first column is a factor, not string 
(or should I use str?). The following is a 2x2 version of the data frame 
after read.csv

       ID    S1-a   S1-b  S2-a  S2-b
1  001-A    1      2     3     4
2  001-B    5      6     7     8
3  002-A    9     10    11    12
4  002-B   13     14    15    16

the resulting data frame I want is (whether or not to retain the factor 
ID info in the resulting data frame is not important)

    S1-a S2-a       S1-b S2-b
1     1    3     1    2    4
2     9   11     2   10   12

    S1-a S2-a       S1-b S2-b
1     5    7     1    6    8
2    13   15     2   14   16

Hope it's clearer.

On 07/25/2009 03:37 AM, jim holtman wrote:
> Are you using 'read.csv'?  At least include an 'str' of the object you
> are wanting to convert so that we know the structure of it, since we
> can not guess at what it is.
> 
> On Sat, Jul 25, 2009 at 4:32 AM, Junqian Gordon Xu<xjqian at gmail.com> wrote:
>> Actually when I read the spreadsheet from cvs file, "S1-[abcd]" are the
>> header and "T1-[abcd]" are the strings in first column of the data frame.
>>
>> Gordon
>>
>> On 07/25/2009 03:13 AM, jim holtman wrote:
>>> It it not entirely clear what the format of your data is. If you have
>>> a dataframe that you would like to separate into several different one
>>> based on the value in a column, then something like this will work:
>>>
>>> df.list <- split(yourDF, yourDF$column)
>>>
>>> This will create a list of dataframes, split according to the contents
>>> of "column".
>>>
>>> On Fri, Jul 24, 2009 at 9:20 PM, Junqian Gordon Xu<xjqian at gmail.com>
>>> wrote:
>>>> 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