apply function to specific columns of data frame

October 5, 2023

I have a big data frame with n number of columns , now i am trying to do sum of rows of all clumns which start with "col" and exclude the columns which ends with "max".

i am getting a error

data <- data.frame(newid= c(212,132,354,222,263,235,233,263,106,135,144),
                   col1= c(1,2,2,1,4,3,2,4,0,5,0),
                   col2= c(1,1,0,3,2,4,1,0,1,3,5),
                   col3= c(1,1,0,3,2,4,1,0,1,3,5),
                   col4= c(1,1,0,3,2,4,1,0,1,3,5),
                   col_max= c("NM","mn","PA","OH","KL","AB","OT","HA","AM","LA","GA"))


df1 <- df %>% summarise(across(starts_with("col_") &  names(df) != ends_with("_max"), ~ sum(.x, na.rm = TRUE)))

>Solution :

df1 <- data %>% summarise(across(starts_with("col") &  !ends_with("_max"), ~ sum(.x, na.rm = TRUE)))

Result:

> df1 <- data %>% summarise(across(starts_with("col") &  !ends_with("_max"), ~ sum(.x, na.rm = TRUE)))
> df1
  col1 col2 col3 col4
1   24   21   21   21

I just modified names(data) != ends_with("_max") to !ends_with("_max").