How to delete the first row of a dataframe in R?

Keep the labels from your original file like this:

df = read.table('data.txt', header = T)

If you have columns named x and y, you can address them like this:

df$xdf$y

If you'd like to actually delete the first row from a data.frame, you can use negative indices like this:

df = df[-1,]

If you'd like to delete a column from a data.frame, you can assign NULL to it:

df$x = NULL

Here are some simple examples of how to create and manipulate a data.frame in R:

# create a data.frame with 10 rows> x = rnorm(10)> y = runif(10)> df = data.frame( x, y )# write it to a file> write.table( df, 'test.txt', row.names = F, quote = F )# read a data.frame from a file: > read.table( df, 'test.txt', header = T )> df$x [1] -0.95343778 -0.63098637 -1.30646529  1.38906143  0.51703237 -0.02246754 [7]  0.20583548  0.21530721  0.69087460  2.30610998> df$y [1] 0.66658148 0.15355851 0.60098886 0.14284576 0.20408723 0.58271061 [7] 0.05170994 0.83627336 0.76713317 0.95052671> df$x = x> df            y           x1  0.66658148 -0.953437782  0.15355851 -0.630986373  0.60098886 -1.306465294  0.14284576  1.389061435  0.20408723  0.517032376  0.58271061 -0.022467547  0.05170994  0.205835488  0.83627336  0.215307219  0.76713317  0.6908746010 0.95052671  2.30610998> df[-1,]            y           x2  0.15355851 -0.630986373  0.60098886 -1.306465294  0.14284576  1.389061435  0.20408723  0.517032376  0.58271061 -0.022467547  0.05170994  0.205835488  0.83627336  0.215307219  0.76713317  0.6908746010 0.95052671  2.30610998> df$x = NULL> df             y1  0.666581482  0.153558513  0.600988864  0.142845765  0.204087236  0.582710617  0.051709948  0.836273369  0.7671331710 0.95052671

You can use negative indexing to remove rows, e.g.:

dat <- dat[-1, ]

Here is an example:

> dat <- data.frame(A = 1:3, B = 1:3)> dat[-1, ]  A B2 2 23 3 3> dat2 <- dat[-1, ]> dat2  A B2 2 23 3 3

That said, you may have more problems than just removing the labels that ended up on row 1. It is more then likely that R has interpreted the data as text and thence converted to factors. Check what str(foo), where foo is your data object, says about the data types.

It sounds like you just need header = TRUE in your call to read in the data (assuming you read it in via read.table() or one of it's wrappers.)

While I agree with the most voted answer, here is another way to keep all rows except the first:

dat <- tail(dat, -1)

This can also be accomplished using Hadley Wickham's dplyr package.

dat <- dat %>% slice(-1)