### Name: str
### Title: Compactly Display the Structure of an Arbitrary R Object
### Aliases: str str.default str.data.frame strOptions
### Keywords: print documentation utilities

### ** Examples

require(stats); require(grDevices); require(graphics)
## The following examples show some of 'str' capabilities
str(1:12)
str(ls)
str(args) #- more useful than  args(args) !
str(freeny)
str(str)
str(.Machine, digits.d = 20)
str( lsfit(1:9,1:9))
str( lsfit(1:9,1:9), max.level = 1)
str( lsfit(1:9,1:9), width = 60, strict.width = "cut")
str( lsfit(1:9,1:9), width = 60, strict.width = "wrap")
op <- options(); str(op) # save first;
                         # otherwise internal options() is used.
need.dev <-
  !exists(".Device") || is.null(.Device) || .Device == "null device"
{ if(need.dev) postscript()
  str(par())
  if(need.dev) graphics.off()
}
ch <- letters[1:12]; is.na(ch) <- 3:5
str(ch) # character NA's

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

str(longch, strict.width = "wrap")

## Settings for narrow transcript :
op <- options(width = 60,
              str = strOptions(strict.width = "wrap"))
str(lsfit(1:9,1:9))
str(options())
## reset to previous:
options(op)

## Don't show: 
 ##-- Some "crazy" objects
 str(array(1:5, dim=20))
 str(factor(character(0)))
 str(as.data.frame(NULL))
## End Don't show
str(quote( { A+B; list(C,D) } ))

## Don't show: 
had.stats4 <- "package:stats4" %in% search()
if(!had.stats4)
   rs <- 
## End Don't show
## S4 classes :
require(stats4)
x <- 0:10; y <- c(26, 17, 13, 12, 20, 5, 9, 8, 5, 4, 8)
ll <- function(ymax=15, xh=6)
      -sum(dpois(y, lambda=ymax/(1+x/xh), log=TRUE))
fit <- mle(ll)
str(fit)
## Don't show: 
if(!had.stats4 && rs) detach("package:stats4")
## End Don't show