[R] selecting columns based on partial names

[Chris Dolanc]

Thank you. That worked.

On 19-Jun-2014 3:24 PM, Uwe Ligges wrote:
>
>
> On 19.06.2014 23:50, Chris Dolanc wrote:
>> Hello,
>>
>> I have a data frame with > 5000 columns and I'd like to be able to make
>> subsets of that data frame made up of certain columns by using part of
>> the column names. I've had a surprisingly hard time finding something
>> that works by searching online.
>>
>> For example, lets say I have a data frame (df) of 2 obs. of 6 variables.
>> The 6 variables are called "1940_tmax", "1940_ppt", "1940_tmin",
>> "1941_tmax", "1941_ppt", "1941_tmin". I want to create a new data frame
>> with only the variables that have "ppt" in the variable (column) name,
>> so that it looks like this:
>>
>> plot name    1940_ppt    1941_ppt
>> 774-CL                    231               344
>> 778-RW                  228               313
>>
>> Thanks.
>>
>
> df[ , grepl("_ppt$", names(df))]
>
> Best,
> Uwe Ligges
>

-- 
Christopher R. Dolanc
Post-doctoral Researcher
University of California, Davis &
University of Montana