Options for R code chunks. When running R code, the object opts_chunk
(default options) is not modified by chunk headers (local chunk options are
merged with default options), whereas opts_current (current options)
changes with different chunk headers and it always reflects the options for
the current chunk.
An object of class list of length 6.
Normally we set up the global options once in the first code chunk in a
document using opts_chunk$set(), so that all latter chunks will
use these options. Note the global options set in one chunk will not affect
the options in this chunk itself, and that is why we often need to set global
options in a separate chunk.
See str(knitr::opts_chunk$get()) for a list of default chunk options.