| str {utils} | R Documentation |
Compactly display the internal structure of an R object, a
“diagnostic” function and an alternative to summary
(and to some extent, 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 any R
object. It calls args for (non-primitive) function objects.
ls.str and lsf.str are useful “versions”
of ls, calling str on each object. They are not
foolproof and should rather not be used for programming, but are
provided for their usefulness.
str(object, ...)
## S3 method for class 'data.frame':
str(object, ...)
## Default S3 method:
str(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(pos = 1, pattern, ..., envir = as.environment(pos), mode = "any",
max.level = 1, give.attr = FALSE)
lsf.str(pos = 1, ..., envir = as.environment(pos))
object |
any R object about which you want to have some information. |
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. |
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. |
digits.d |
number of digits for numerical components (as for
print). |
nchar.max |
maximal number of characters to show for
character strings. Longer strings are truncated, see
longch example below. |
give.attr |
logical; if TRUE (default), show attributes
as sub structures. |
give.length |
logical; if TRUE (default), indicate
length (as [1:...]). |
wid |
the page width to be used. The default is the currently
active options("width"). |
nest.lev |
current nesting level in the recursive calls to
str. |
indent.str |
the indentation string to use. |
... |
potential further arguments (required for Method/Generic reasons). |
pos |
integer indicating search path position. |
envir |
environment to use, see ls. |
pattern |
a regular expression passed to ls.
Only names matching pattern are considered. |
mode |
character specifying the mode of objects to
consider. Passed to exists and get. |
str does not return anything, for efficiency reasons.
The obvious side effect is output to the terminal.
ls.str and lsf.str invisibly return a character vector
of the matching names, similarly to ls.
Martin Maechler maechler@stat.math.ethz.ch since 1990.
require(stats)
## 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()
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)
lsf.str()#- how do the functions look like which I am using?
ls.str(mode = "list") #- what are the structured objects I have defined?
## which base functions have "file" in their name ?
lsf.str(pos = length(search()), pattern = "file")