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 also use xtabs or tapply:

xtabs(cbind(bsent, breturn, tsent, treturn, csales) ~ yname, data)

tapply(data$bsent, data$yname, sum)