How do I remove columns in R?

The most easiest way to drop columns is by using subset() function. In the code below, we are telling R to drop variables x and z. The ‘-‘ sign indicates dropping variables. Make sure the variable names would NOT be specified in quotes when using subset() function.

How do I keep only certain columns in R?

To select a column in R you can use brackets e.g., YourDataFrame[‘Column’] will take the column named “Column”. Furthermore, we can also use dplyr and the select() function to get columns by name or index. For instance, select(YourDataFrame, c(‘A’, ‘B’) will take the columns named “A” and “B” from the dataframe.

How do I remove a specific character in R?

Remove Last Character From String in R

  1. Use the substr() Function to Remove the Last Characters in R.
  2. Use the str_sub() Function to Remove the Last Characters in R.
  3. Use the gsub() Function to Remove the Last Characters in R.

How do I delete specific rows in R?

Delete Rows from R Data Frame You cannot actually delete a row, but you can access a data frame without some rows specified by negative index. This process is also called subsetting in R language. A Big Note: You should provide a comma after the negative index vector -c().

How do I change a column name in R?

Method 1: using colnames() method colnames() method in R is used to rename and replace the column names of the data frame in R. The columns of the data frame can be renamed by specifying the new column names as a vector. The new name replaces the corresponding old name of the column in the data frame.

How do I remove multiple columns in R?

For example, if you want to remove the columns “X” and “Y” you’d do like this: select(Your_Dataframe, -c(X, Y)) . Note, in that example, you removed multiple columns (i.e. 2) but to remove a column by name in R, you can also use dplyr, and you’d just type: select(Your_Dataframe, -X) .

How do I extract multiple columns in R?

To pick out single or multiple columns use the select() function. The select() function expects a dataframe as it’s first input (‘argument’, in R language), followed by the names of the columns you want to extract with a comma between each name.

How do I remove the first character from a column in R?

If we need to remove the first character, use sub , match one character ( . represents a single character), replace it with ” . Or for the first and last character, match the character at the start of the string ( ^. ) or the end of the string ( . $ ) and replace it with ” .

How do I remove the first row in R?

1 Answer

  1. To delete the first row of a data frame, you can use the negative indices as follows: data_frame = data_frame[-1,]
  2. To keep labels from your original file, do the following: data_frame = read.table(‘data.txt’, header = T)
  3. To delete a column: data_frame$column_name = NULL. For example: x = rnorm(10) y = runif(10)