Is there a method for moving a column from one position in a data.frame to the next - without typing an entirely new data.frame()
For example:
a <- b <- c <- d <- e <- f <- g <- 1:100
df <- data.frame(a,b,c,d,e,f,g)
Now let's say I wanted "g" in front of "a"
I could retype it, as
df <- data.frame(g,a,b,c,d,e,f)
But is there not a quicker way? (Imagine 1500+ columns)
Use relocate from dplyr package
mtcars %>%
# dplyr::relocate(disp) %>% ## simply make disp the first column
relocate(starts_with("c"), .after = disp) %>% ## more complex column order shuffling
head(3)
Note, that the function was added with version 1.0, see https://www.tidyverse.org/blog/2020/03/dplyr-1-0-0-select-rename-relocate/
This is a very old post , but I developed this code which dynamically changes column position within a dataframe. Just change the value of n and Column Name ("g" here) and get dataframe with new column arrangements.
df1 = subset(df, select = c(head(names(df),n=3),"g", names(df) [! names(df) %in% c(head(names(df),n=3),"g")]))
Here is a simple but flexible function I wrote to move a column anywhere in a data frame.
move.col <- function(df, move_this, next_to_this, before = FALSE) {
if (before==FALSE)
df[,c(match(setdiff(names(df)[1:which(names(df)==next_to_this)],move_this),names(df)),
match(move_this,names(df)),
match(setdiff(names(df)[which(names(df)==next_to_this):ncol(df)],c(next_to_this,move_this)),names(df)))]
else
df[,c(match(setdiff(names(df)[1:(which(names(df)==next_to_this))],c(next_to_this,move_this)),names(df)),
match(move_this,names(df)),
match(setdiff(names(df)[(which(names(df)==next_to_this)):ncol(df)],move_this),names(df)))]
}
Usage:
Specify the data frame (df), the column name you want to move (move_this), and the column name of which you want to move beside (next_to_this). By default, the function will move the move_this column after the next_to_this column. You can specify before = TRUE to move move_this before next_to_this.
Examples:
move.col(df, "b", "g")
move.col(df, "c", "e")
move.col(df, "g", "a", before=TRUE)
move.col(df,c("d","f"),"b", before=TRUE)
I found a pretty simple way of doing this that suited my needs and doesn't take much time.
You have the following column names: "a", "b", "c", "d", "e", "f", "g", "h", "i", "j"
Move "d" to second position (after "a"):
attach(df)
df <- cbind(a, d, df[,c(2:3,5:10)])
Move "j" to 4th position (after "c"):
df <- cbind(df[,c(1:3)], j, df[,c(4:9)])
For data.table users :
Use setcolorder().
setDT(df) # convert into data.table
setcolorder(df,'g') # column g comes first if not all column names are mentioned
setcolorder(df, 7) # same as above
df
g a b c d e f
1: 1 1 1 1 1 1 1
2: 2 2 2 2 2 2 2
3: 3 3 3 3 3 3 3
4: 4 4 4 4 4 4 4
5: 5 5 5 5 5 5 5
6: 6 6 6 6 6 6 6
7: 7 7 7 7 7 7 7
In case when column 'a' and 'b' should be moved to rightmost:
setcolorder(df,3:7)
df
c d e f g a b
1: 1 1 1 1 1 1 1
2: 2 2 2 2 2 2 2
3: 3 3 3 3 3 3 3
4: 4 4 4 4 4 4 4
5: 5 5 5 5 5 5 5
6: 6 6 6 6 6 6 6
7: 7 7 7 7 7 7 7