通过根据 R 中的分位数分配值在数据框中生成新列？

Question

Let's make a dummy vector called INCOME <- rnorm(1:1000, 500, 100)

Then let's take quantiles using function 'quantile': INCOME_QUANTILES <- quantile(INCOME, probs=c(0.05, 0.50, 1.00))

Now I want to make a new vector called INCOME QUANTILE and attach this to my vector INCOME to create a data frame of 2 columns (INCOME / INCOME QUANTILE) of 1000 observations. In this new vector should go a value of 1, 2, or 3, depending on which income quantile that observation falls into, so a value of 1 = 0.05 quantile, 2 = 0.50 quantile, and 3 = 1.00 quantile.

So for example, if the first observation of income falls into the 1.00 quantile, and the second observation falls into the 0.50 quantile, it'll look like:

INCOME   INCOME QUANTILE
550.50         3
415.20         2

It's been suggested by a friend to create a for loop, but I'm honestly not sure at all how to go about that. Any help would be very appreciated!

Answer 1

You can try this:

INCOME <- rnorm(1:1000, 500, 100)
INCOME_QUANTILES <- quantile(INCOME, probs=c(0, 0.05, 0.50, 1.00))

df <- data.frame(INCOME, 
                 INCOME_GOUP = as.numeric(cut(INCOME, breaks = INCOME_QUANTILES, include.lowest = TRUE)))

Note that I had to add 0 as the lowest quantile. So it's 0-0.05 = 1, >.05-.5 = 2, >.5 = 3.