Given a dataframe df which I generate as follows:
set.seed(1)
b <- runif(100)
set.seed(1)
a <- sample.int(9, 100, replace = TRUE)
df <- data.frame(a,b)
I formed a frequency table as shown below but not satisfied:
sortted_a <- data.frame(table(df$a))
sortted_a
# Var1 Freq
#1 1 14
#2 2 8
#3 3 10
#4 4 9
#5 5 11
#6 6 11
#7 7 5
$8 8 14
#9 9 18
I rather want a table that will not only show the frequency of vector a but will display frequency of a along with the associated averages of vector b as follows in R:
# Var1 Freq Ave_b
#1 1 14 0.6750
#2 2 8 0.0027
#3 3 10 0.8298
#4 4 9 0.1873
#5 5 11 0.3874
#6 6 11 0.7632
#7 7 5 0.5812
$8 8 14 0.5478
#9 9 18 0.4389
If you want to stick with base R, you can use tapply() to find the average of b by a and then cbind() with your sorted data.frame:
ave_b <- tapply(df$b,df$a,mean)
new_df <- cbind(sortted_a, ave_b)