\Header{str}{Compactly Display the Structure of an Arbitrary R Object}
\alias{ls.str}{str}
\alias{lsf.str}{str}
\methalias{str.data.frame}{str}
\methalias{str.default}{str}
\keyword{print}{str}
\keyword{documentation}{str}
\keyword{utilities}{str}
\begin{Description}\relax
This is a ``diagnostic'' function, and an alternative to
\code{\Link{summary}} (and to some extent, \code{\Link{dput}}).  Ideally,
only one line for each ``basic'' structure is displayed.  It is especially
well suited to compactly display the (abbreviated) contents of
(possibly nested) lists.  The idea is to give reasonable output for
\bold{any} \R{} object.  It calls \code{\Link{args}} for (non-primitive)
function objects.

\code{\Link{ls.str}} and \code{\Link{lsf.str}} are useful ``versions''
of \code{\Link{ls}}, calling \code{str} on each object.  They are not
foolproof and should rather not be used for programming, but are
provided for their usefulness.\end{Description}
\begin{Usage}
\begin{verbatim}
str(object, ...)
str.data.frame(object, ...)
str.default(object, max.level = 0, vec.len = 4, digits.d = 3,
    nchar.max = 128, give.attr = TRUE, give.length = TRUE,
    wid = getOption("width"), nest.lev = 0,
    indent.str = paste(rep(" ", max(0, nest.lev + 1)), collapse = ".."))

ls.str(name, pattern, mode = "any", max.level = 1, give.attr = FALSE)
lsf.str(...)
\end{verbatim}
\end{Usage}
\begin{Arguments}
\begin{ldescription}
\item[\code{object}] any \R{} object about which you want to have some
information.
\item[\code{max.level}] maximal level of nesting which is applied for
displaying nested structures, e.g., a list containing sub lists.
Default 0: Display all nesting levels.
\item[\code{vec.len}] numeric (>= 0) indicating how many ``first few'' elements
are displayed of each vector.  The number is multiplied by different
factors (from .5 to 3) depending on the kind of vector.  Default 4.
\item[\code{digits.d}] number of digits for numerical components (as for
\code{\Link{print}}).
\item[\code{nchar.max}] maximal number of characters to show for
\code{\Link{character}} strings.  Longer strings are truncated, see
\code{longch} example below.
\item[\code{give.attr}] logical; if \code{TRUE} (default), show attributes
as sub structures.
\item[\code{give.length}] logical; if \code{TRUE} (default), indicate
length (as \code{[1:...]}).
\item[\code{wid}] the page width to be used.  The default is the currently
active \code{\Link{options}("width")}.
\item[\code{nest.lev}] current nesting level in the recursive calls to
\code{str}.
\item[\code{indent.str}] the indentation string to use.
\end{ldescription}
\end{Arguments}
\begin{Value}
Nothing, for efficiency reasons.
The obvious side effect is output to the terminal.\end{Value}
\begin{Author}\relax
Martin Maechler \email{maechler@stat.math.ethz.ch} since 1990.\end{Author}
\begin{SeeAlso}\relax
\code{\Link{summary}}, \code{\Link{args}}.\end{SeeAlso}
\begin{Examples}
\begin{ExampleCode}
## The following examples show some of `str' capabilities
str(1:12)
str(ls)
str(args)#- more useful than  args(args) !
data(freeny); str(freeny)
str(str)
str(.Machine, digits = 20)
str( lsfit(1:9,1:9))
str( lsfit(1:9,1:9),  max =1)
op <- options(); str(op)#- save first; otherwise internal options() is used.
need.dev <- !exists(".Device") || is.null(.Device)
if(need.dev) postscript()
str(par()); if(need.dev) graphics.off()

nchar(longch <- paste(rep(letters,100), collapse=""))
str(longch)
str(longch, nchar.max = 52)

lsf.str()#- how do the functions look like which I am using?
ls.str(mode = "list")#- what are the structured objects I have defined?

\end{ExampleCode}
\end{Examples}

