Merge rows with duplicate IDs

Question

I would like to merge and sum the values of each row that contains duplicated IDs.

For example, the data frame below contains a duplicated symbol \'LOC102723897\'. I wou

Answer 1

You group-by on Symbol and sum all columns.

library(dplyr)
df %>% group_by(Symbol) %>% summarise_all(sum)

using data.table

library(data.table)
 setDT(df)[ , lapply(.SD, sum),by="Symbol"]

Answer 2

We can just use aggregate from base R

aggregate(.~ Symbol, df, FUN = sum)