[R] rename and concatenate name of columns

[Rainer Schuermann]

df1 <- data.frame( A = runif( 10 ), B = runif( 10 ) * 5, C = runif( 10 ) * 10, D = runif( 10 ) * 20 )
df2 <- data.frame( X = runif( 10 ), Y = runif( 10 ) * 5, Z = runif( 10 ) * 10 )
rename_columns <- function( dataset )
{
	for( i in 2:ncol( dataset ) )
		colnames( dataset )[i] <- paste( colnames( dataset )[1], colnames( dataset )[i], sep = "_" )
	return( dataset )
}

df1 <- rename_columns( df1 )  
df1
            A       A_B          A_C       A_D
1  0.79914742 4.4898911 2.8869670979 11.067921
2  0.34552180 3.5456202 7.4774973304  8.610913
3  0.02950957 3.1754457 2.4493258283 17.649965
4  0.41804920 3.6180818 2.4680344155  5.038590
5  0.69496877 1.7169792 0.8790624910  3.476689
6  0.79293910 0.4452258 9.5359219401  3.668066
7  0.06135734 0.9188141 8.4256720915  9.980292
8  0.86066946 1.2674735 4.1982888198 13.561160
9  0.41895427 0.1434889 0.0007853331  3.187101
10 0.09498189 4.5215823 1.0008131783 10.428556





On Friday 14 June 2013 18:04:22 Arman Eshaghi wrote:
> Dear all,
> 
> I have different data frames for which I would like to modify names of each
> column such that the new name would include the name of the first column
> added to the name of other columns; I came up with the following code.
> Nothing changes when I run the following code. I would be grateful if
> someone could help me.
> 
> All the best,
> -Arman
> 
> rename_columns <- function(dataset) {
> for (i in 2:(ncol(dataset))) {names(dataset)[i] <- paste(names(dataset)[1],
> names(dataset)[i], sep="_")
> }
> }
> 
> rename_columns(dataset) %nothing happens!
> 
> 	[[alternative HTML version deleted]]
> 
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