Am 08.02.2012 um 23:47 schrieb David Winsemius:
>
> On Feb 8, 2012, at 5:06 PM, Johannes Radinger wrote:
>
>>
>> Am 08.02.2012 um 22:19 schrieb David Winsemius:
>>
>>>
>>> On Feb 8, 2012, at 4:11 PM, Johannes Radinger wrote:
>>>
>>>> Hi,
>>>>
>>>> I want to split a dataframe based on a grouping variable (in one column).
>>>> The resulting new
>>>> dataframes should be stored in a new variable. I tried to split the
>>>> dataframe using split() and
>>>> to store it using a FOR loop, but thats not working so far:
>>>>
>>>> df <- data.frame(A=c("A1","A1","A2","A2"),B=seq(1:4))
>>>>
>>>> Fsplit <- function(x,y){
>>>> ls <- split(x,f=x$y)
>>>> for (i in names(ls)){
>>>> i <- ls$i
>>>> }
>>>> }
>>>>
>>>> Fsplit(df,A) #1st argument is dataframe to split, 2nd argument grouping
>>>> variable
>>>>
>>>
>>> It appears you want the name of the levels of df$A to be the names of
>>> separate variables in the global environment. If that is correct, then see
>>> the FAQ. I'm not sure which one it is among the Miscellaneous section, but
>>> you should be looking of the one that tells you how to construct a named
>>> variable.
>>>
>>
>> Your hint with the global environment brought me on track. It seems that I
>> this task can be done with list2env() although there is still a problem with
>> my function. How
>> can I parse the name of the dataframe and the column name in the function...
>>
>> df <- data.frame(A=c("A1","A1","A2","A2"),B=seq(1:4))
>>
>> Fsplit <- function(x,y){
>> ls <- split(x,f=x$y)
>> list2env(ls,envir = .GlobalEnv)
>> }
>>
>> Fsplit(df,A)
>
> I still have not figured out what you really want to do. The simple answer to
> what you ask for in your written request is simply:
>
> dfvar <- split(df, df$A)
>
> So what is it about that result that is not useful for your (as yet unstated)
> destination?
>
> > split(df, df$A)
> $A1
> A B
> 1 A1 1
> 2 A1 2
>
> $A2
> A B
> 3 A2 3
> 4 A2 4
>
>
Sorry for not being clear enough, and your are
right as "split(df, df$A)" is what I want. Additionally I want to store
afterwards
the single objects of the list in new dataframes
where variable name = name of list object (which can be done with list2env()).
Is that clear enough so far?
What I want exactly is to express that two operations (split, list2env) within
one function. I need the function for other tasks in R.
/johannes
>
>
>
>>
>> /johannes
>>
>>> Or:
>>>
>>> ? assign
>>>
>>> --
>>> David Winsemius, MD
>>> West Hartford, CT
>>>
>>
>
> David Winsemius, MD
> West Hartford, CT
>
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