Find duplicates in column x, then remove row that has lower value in column y

Question

In my data frame, I am having some single observations and some double observations. In the situation of double observations in x, I want to pick the row with the lower 'y' value so that in future I can remove that row.

ex <- data.frame('x'= c(1:5, 1:3,5:6), 'y'= c(70,73,72,49,60,14,50,46,13,29))

The original data frame is:

And this is what I want:

 

Answer 1

If you want to sort the 'y' on the basis of the lower value then in that case in R Programming, you can use the aggregate() as this will help you in finding the largest number per group:

aggregate(y ~ x, ex, max)

#  x  y

#1 1 70

#2 2 73

#3 3 72

#4 4 49

#5 5 60

#6 6 29