[R] selecting columns based on partial names

[Uwe Ligges]

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