Coerce an Object for Graphics Annotation
Coerce an R object into a form suitable for graphics annotation.
an R object
Expressions, calls and names (as used by plotmath) are passed
through unchanged. All other objects with an explicit class (as
is.object) are coerced by
as.character to character vectors.
All the graphics and grid functions which use this coerce calls and names to expressions internally.
A language object or a character vector.