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

### ** Examples

require(stats)
## 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 = 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()

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)

## 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