Jun,
sapply() does the trick! Thank you Jun! I really appreciate your help.
-Matt
On Tue, May 12, 2009 at 1:20 PM, Jun Shen <jun.shen...@gmail.com> wrote:
> Forgot one thing, make sure your data is a list or data frame.
>
>
> On Tue, May 12, 2009 at 12:19 PM, Jun Shen <jun.shen...@gmail.com> wrote:
>
>> I don't think get(factor[i]) will work. The problem is get only sees a
>> character string "data$focus" instead of doing "extracting focus from data".
>> In your case isn't lapply (or sapply) good enough?
>>
>> sapply (data, summary)
>>
>> try ?lapply for details
>>
>> Jun
>>
>> On Tue, May 12, 2009 at 10:55 AM, rapton <mattc...@gmail.com> wrote:
>>
>>>
>>> Hello,
>>>
>>> I have a data set with many variables, and often I want to run a given
>>> function, like summary() or cor() or lmer() etc. on many combinations of
>>> one
>>> or more than one of these variables. For every combination of variables
>>> I
>>> want to analyze I have been writing out the code by hand, but given that
>>> I
>>> want to run many different functions over dozens and dozens of variables
>>> combinations it is taking a lot of time and making for very inelegent
>>> code.
>>> There *has* to be a better way! I have tried looking through numerous
>>> message boards but everything I've tried has failed.
>>>
>>> It seems like loops would solve this problem nicely.
>>> (1) Create list of variables of interest
>>> (2) Iterate through the list, running a given function on each variable
>>>
>>> I have a data matrix which I have creatively called "data". It has
>>> variables named "focus" and "productive".
>>>
>>> If I run the function summary(), for instance, it works fine:
>>> summary(data$focus)
>>> summary(data$productive)
>>>
>>> Both of these work.
>>>
>>> If I try to use a loop like:
>>>
>>> factors <- c("data$focus", "data$productive")
>>> for(i in 1:2){
>>> summary(get(factors[i]))
>>> }
>>>
>>> It given the following errors:
>>> Error in get(factors[i]) : variable "data$focus" was not found
>>> Error in summary(get(factors[i])) :
>>> error in evaluating the argument 'object' in selecting a method for
>>> function 'summary'
>>>
>>> But data$focus *does* exist! I could run summary(data$focus) and it
>>> works
>>> perfectly.
>>>
>>> What am I doing wrong?
>>>
>>> Even if I get this working, is there a better way to do this, especially
>>> if
>>> I have dozens of variables to analyze?
>>>
>>> Any ideas would be greatly appreciated!
>>> --
>>> View this message in context:
>>> http://www.nabble.com/Using-loops-to-run-functions-over-a-list-of-variables-tp23505399p23505399.html
>>> Sent from the R help mailing list archive at Nabble.com.
>>>
>>> ______________________________________________
>>> R-help@r-project.org mailing list
>>> https://stat.ethz.ch/mailman/listinfo/r-help
>>> PLEASE do read the posting guide
>>> http://www.R-project.org/posting-guide.html
>>> and provide commented, minimal, self-contained, reproducible code.
>>>
>>
>>
>>
>> --
>> Jun Shen PhD
>> PK/PD Scientist
>> BioPharma Services
>> Millipore Corporation
>> 15 Research Park Dr.
>> St Charles, MO 63304
>> Direct: 636-720-1589
>>
>>
>
>
> --
> Jun Shen PhD
> PK/PD Scientist
> BioPharma Services
> Millipore Corporation
> 15 Research Park Dr.
> St Charles, MO 63304
> Direct: 636-720-1589
>
>
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