This function turns unevaluated expressions (where expression
is taken in a wider sense than the strict concept of a vector of mode
"expression"
used in expression
) into character
strings (a kind of inverse to parse
). A typical use of this is to create informative labels for data sets
and plots. The example shows a simple use of this facility. It uses
the functions deparse
and substitute
to create labels
for a plot which are character string versions of the actual arguments
to the function myplot
.
The default for the backtick
option is not to quote single
symbols but only composite expressions. This is a compromise to
avoid breaking existing code.
Using control = "all"
comes closest to making deparse()
an inverse of parse()
. However, not all objects are
deparse-able even with this option and a warning will be issued if the
function recognizes that it is being asked to do the impossible.
Numeric and complex vectors are converted using 15 significant digits:
see as.character
for more details.
width.cutoff
is a lower bound for the line lengths: deparsing a
line proceeds until at least width.cutoff
bytes have
been output and e.g.\ifelse{latex}{\out{~}}{ } arg = value
expressions will not be split
across lines.