9.4 Hide everything from a chunk
Sometimes we may want to execute a code chunk without showing any output at all. Instead of using separate options mentioned in Section 9.3, we can suppress the entire output of the code chunk using a single option
include = FALSE, e.g.,
include=FALSE, the code chunk will be evaluated (unless
eval=FALSE), but the output will be completely suppressed—you will not see any code, text output, messages, or plots.