search for: sum_of_counts

Displaying 1 result from an estimated 1 matches for "sum_of_counts".

2009 Aug 26
2
counting subgroup sums within a data frame
...3 8/4/2009 B Y 5 8/5/2009 A X 3 8/5/2009 B X 7 8/5/2009 A Y 2 8/5/2009 B Y 1 I would like to create a data frame of the sum the daily counts for, say, class 'A', like so: Date sum_of_counts 8/1/2009 10 8/2/2009 5 8/3/2009 9 8/4/2009 4 8/5/2009 5 I ultimately would like to do sum of counts on all classes and subclasses. It seems that this is equivalent to a GROUP BY query in SQL. I'm sure this is possible in R. Any suggestions? [[alternati...