How to aggregate data in data.frame in R

Question

I have a large data.frame. The data.frame include a lot of values.

For example:

df <- data.frame(Company = c(\'A\', \'A\', \'B\', \'C\', \'A\', \'         


        

Answer 1

Base R

cbind(aggregate(.~Company, df[,-c(2, 5)], mean),
      aggregate(Education.University~Company, df, sum)[-1])
#  Company      Age    Wages Productivity Education.University
#1       A 27.00000 56666.67     102.6667                    2
#2       B 28.66667 68333.33     111.6667                    3
#3       C 29.00000 53333.33     101.6667                    1

Here is the longer version that may be easier to understand

merge(x = aggregate(x = list(Age_av = df$Age,
                             Wages_av = df$Wages,
                             Productivity_av = df$Productivity),
                by = list(Company = df$Company),
                FUN = mean),
      y = aggregate(x = list(Education.University_sum = df$Education.University),
                by = list(Company = df$Company),
                FUN = sum),
      by = "Company")
#  Company   Age_av Wages_av Productivity_av Education.University_sum
#1       A 27.00000 56666.67        102.6667                        2
#2       B 28.66667 68333.33        111.6667                        3
#3       C 29.00000 53333.33        101.6667                        1