Fastest way to find second (third...) highest/lowest value in vector or column?

Question

R offers max and min, but I do not see a really fast way to find the another value in the order apart from sorting the whole vector and than picking value x from this vector.Is there a faster way to get the second highest value (e.g.)?Thanks

Answer 1

Fastest way that I can think of to specifically find the second highest value from a vector:

## R CODE:

> ## create vector

> vector_data <- c(1, 4, 5, 6, 9)

> is.vector(vector_data)

[1] TRUE

> ## get second highest ranking number in the vector

> new_vector <- vector_data[! vector_data %in% max(vector_data)]

> new_vector

[1] 1 4 5 6

> max(new_vector)

[1] 6

You can replace max() with min() if you'd like to go the opposite way.

Other way that I would prefer:

1. Convert the vector to a column in a dataframe. Sort the dataframe in ascending or descending order and reset the index. Create a rank column that mirrors that index. Now you have a rank column from which you can subset.

But like you said, you can also sort the vector in descending or ascending order, then select by position.