Hi, I am writing a script that will address columns using syntax like: data_set[,1] to extract the data from the first column of my data set, for example. This code will be placed in a loop (where the column reference will be placed by a variable). What I also need to do is extract the column NAME for a given column being processed in the loop. The dataframe has been set so that R knows that the top line refers to column headers. Can anyone help me understand how to do this? Thanks. -- View this message in context: http://www.nabble.com/Extracting-a-column-name-in-loop--tp24393160p24393160.html Sent from the R help mailing list archive at Nabble.com.
On Wed, Jul 8, 2009 at 8:41 AM, mister_bluesman<mister_bluesman at hotmail.com> wrote:> > Hi, > > I am writing a script that will address columns using syntax like: > > data_set[,1] > > to extract the data from the first column of my data set, for example. This > code will be placed in a loop (where the column reference will be placed by > a variable). > > What I also need to do is extract the column NAME for a given column being > processed in the loop. The dataframe has been set so that R knows that the > top line refers to column headers. > > Can anyone help me understand how to do this? > > Thanks.Possibly something like names(data_set)[i] ? HTH, Mark
If df is your dataframe then names(df) contains the column names and so names(df)[i] is the name of i-th column. --- On Thu, 9/7/09, mister_bluesman <mister_bluesman at hotmail.com> wrote:> From: mister_bluesman <mister_bluesman at hotmail.com> > Subject: [R] Extracting a column name in loop? > To: r-help at r-project.org > Received: Thursday, 9 July, 2009, 1:41 AM > > Hi, > > I am writing a script that will address columns using > syntax like: > > data_set[,1] > > to extract the data from the first column of my data set, > for example. This > code will be placed in a loop (where the column reference > will be placed by > a variable). > > What I also need to do is extract the column NAME for a > given column being > processed in the loop. The dataframe has been set so that R > knows that the > top line refers to column headers. > > Can anyone help me understand how to do this? > > Thanks. > -- > View this message in context: http://www.nabble.com/Extracting-a-column-name-in-loop--tp24393160p24393160.html > Sent from the R help mailing list archive at Nabble.com. > > ______________________________________________ > R-help at 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. >
Thank you both for that. Much appreciated. mister_bluesman wrote:> > Hi, > > I am writing a script that will address columns using syntax like: > > data_set[,1] > > to extract the data from the first column of my data set, for example. > This code will be placed in a loop (where the column reference will be > placed by a variable). > > What I also need to do is extract the column NAME for a given column being > processed in the loop. The dataframe has been set so that R knows that the > top line refers to column headers. > > Can anyone help me understand how to do this? > > Thanks. >-- View this message in context: http://www.nabble.com/Extracting-a-column-name-in-loop--tp24393160p24407422.html Sent from the R help mailing list archive at Nabble.com.