sorting - R: Sort columns of a data frame by a vector of column names

Question

I have a data.frame that looks like this:

which has 1000+ columns with similar names.

And I have a vector of those column names that looks like this:

The vector is sorted by the cluster_id (which goes up to 11).

I want to sort the columns in the data frame such that the columns are in the order of the names in the vector.

A simple example of what I want is that:

Data:

 A    B    C
 1    2    3
 4    5    6

Vector: c("B","C","A")

Sorted:

 B    C    A
 2    3    1
 5    6    4

Is there a fast way to do this?

Answer 1

UPDATE, with reproducible data added by OP:

df <- read.table(h=T, text="A    B    C
    1    2    3
    4    5    6")
vec <- c("B", "C", "A")
df[vec]

Results in:

  B C A
1 2 3 1
2 5 6 4

As OP desires.

---

How about:

df[df.clust$mutation_id]

Where df is the data.frame you want to sort the columns of and df.clust is the data frame that contains the vector with the column order (mutation_id).

This basically treats df as a list and uses standard vector indexing techniques to re-order it.