Re: [R] How to sum one column in a data frame keyed on other columns

2:00 525 > > > sumUp(dat, "url", "visits") > url total_visits > 4 www.bar.com 400 > 1 www.foo.com 675 > > Question for the reader: why to you need 'drop = FALSE' (in three > places)? > >

[R] How to sum one column in a data frame keyed on other columns

I have a data frame that looks like this: url time somethingirrelevant visits www.foo.com 1:00 xxx 100 www.foo.com 1:00 yyy 50 www.foo.com 2:00 xyz 25 www.bar.com 1:00 xxx 200 www.bar.com 1:00 zzz 200 www.foo.c