usage {formatR} | R Documentation |
Print the reformatted usage of a function. The arguments of the function are
searched by argsAnywhere
, so the function can be either
exported or non-exported in a package. S3 methods will be marked.
usage(FUN, width = getOption("width"), tidy = TRUE, output = TRUE, indent.by.FUN = FALSE, fail = c("warn", "stop", "none"))
FUN |
the function name |
width |
the width of output |
tidy |
whether to reformat the usage code |
output |
whether to write the output to the console (via
|
indent.by.FUN |
whether to indent subsequent lines by the width of the function name (see “Details”) |
fail |
a character string that determines whether to generate a warning,
stop, or do neither, if the width constraint is unfulfillable (default is
|
Line breaks in the output occur between arguments. In particular, default values of arguments will not be split across lines.
When indent.by.FUN
is FALSE
, indentation is set by the option
getOption("formatR.indent", 4L)
, the default value of the
indent
argument of tidy_source
.
The R code for the usage is returned as a character string (invisibly).
library(formatR) usage(var) usage(plot) usage(plot.default) # default method usage("plot.lm") # on the 'lm' class usage(usage) usage(barplot.default, width = 60) # output lines have 60 characters or less # indent by width of 'barplot(' usage(barplot.default, width = 60, indent.by.FUN = TRUE) ## Not run: # a warning is raised because the width constraint is unfulfillable usage(barplot.default, width = 30) ## End(Not run)