Find centralized, trusted content and collaborate around the technologies you use most.
Teams
Q&A for work
Connect and share knowledge within a single location that is structured and easy to search.
これをどのように複製しplyrますか？
plyr
with(mtcars, tapply(mpg, cyl, summary))
同じ優雅さで、つまり、個々の統計を綴ることなく？