Counting and summing with dplyr

Question

I have the following dataframe.

Name <- c("John","Mark","Ella","Mike","Zedd","John","Maria","Nick","John","Nick","Zedd","Andrea")
Age <- c(16,25,45,23,26,28,19,20,43,31,33,15)
df <- data.frame(Name,Age)

I want to group by name and sum the years of age. This what I am using without success.

library(dplyr)
new_df <- group_by(Name) %>% summarise(Years = sum(Age)), count = count(Name))

Do you need `df %>% group_by(Name) %>% summarise(Age = sum(Age)) ` ? — Ronak Shah, Apr 19 '20 at 14:31

score 1 · Answer 1 · answered Apr 19 '20 at 14:34

1

Do you mean:

library(dplyr

df <- data.frame(Name,Age) %>% 
  group_by(Name) %>% 
  summarise(Years = sum(Age, rm.na = TRUE),
            count = n())

answered Apr 19 '20 at 14:34

Peter

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Counting and summing with dplyr

1 Answers1