Calculating subtotals in R

Question

I have a data frame with 900,000 rows and 11 columns in R. The column names and types are as follows:

column name: date / mcode / mname / ycode / yname / yissue          


        

Answer 1

You can use aggregate

For instance, say that you have

val = rnorm(50)
name = rep(letters[1:5], each=10)
data <- data.frame(val, name)

Then you can do

aggregate(data$val, by=list(data$name), FUN=sum)