I suspect Hadley would recommend reading his new book, R for Data Science (r4ds.had.co.nz), in particular Chapter 3. You don't need plyr, but it won't take long before you will want to be using dplyr and tidyr, which are covered in later chapters. -- Sent from my phone. Please excuse my brevity.
On February 20, 2017 6:53:29 PM PST, C W <tmrs...@gmail.com> wrote: >Thanks Hadley! > >While I got your attention, what is a good way to get started on >ggplot2? ;) > >My impression is that I first need to learn plyr, dplyr, AND THEN >ggplot2. >That's A LOT! > >Suppose i have this: >iris >iris2 <- cbind(iris, grade = sample(1:5, 150, replace = TRUE)) >iris2 > >I want to have some kind of graph conditioned on species, by grade . >What's >a good lead to learn about plotting this? > >Thank you! > > > >On Mon, Feb 20, 2017 at 11:12 AM, Hadley Wickham <h.wick...@gmail.com> >wrote: > >> On Sun, Feb 19, 2017 at 3:01 PM, David Winsemius ><dwinsem...@comcast.net> >> wrote: >> > >> >> On Feb 19, 2017, at 11:37 AM, C W <tmrs...@gmail.com> wrote: >> >> >> >> Hi R, >> >> >> >> I am a little confused by the data.table package. >> >> >> >> library(data.table) >> >> >> >> df <- data.frame(w=rnorm(20, -10, 1), x= rnorm(20, 0, 1), >y=rnorm(20, >> 10, 1), >> >> z=rnorm(20, 20, 1)) >> >> >> >> df <- data.table(df) >> > >> > df <- setDT(df) is preferred. >> >> Don't you mean just >> >> setDT(df) >> >> ? >> >> setDT() modifies by reference. >> >> >> >> >> df_3 <- df[, a := x-y] # created new column a using x minus y, why >are >> we >> >> using colon equals? >> > >> > You need to do more study of the extensive documentation. The >behavior >> of the ":=" function is discussed in detail there. >> >> You can get to that documentation with ?":=" >> >> Hadley >> >> -- >> http://hadley.nz >> > > [[alternative HTML version deleted]] > >______________________________________________ >R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see >https://stat.ethz.ch/mailman/listinfo/r-help >PLEASE do read the posting guide >http://www.R-project.org/posting-guide.html >and provide commented, minimal, self-contained, reproducible code. ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
