str
Compactly Display the Structure of an Object

Description

Displays the structure of any object in a compact form. If possible, the brief structure of a basic object is displayed in one line. For nested objects and attributes, each component is displayed indented on a separate line.

Usage

# Generic function:
str(object, ...)
## Default S3 method:
str(object, max.level = NA, vec.len = strO$vec.len, digits.d = strO$digits.d,
    nchar.max = 128, give.attr = TRUE, give.head = TRUE, give.length = give.head,
    width = getOption("width"), nest.lev = 0, indent.str = paste(rep.int(" ",
        max(0, nest.lev + 1)), collapse = ".."), comp.str = "$ ",
    no.list = FALSE, envir = baseenv(), strict.width = strO$strict.width,
    formatNum = strO$formatNum, list.len = 99, ...)

strOptions(strict.width = "no", digits.d = 3, vec.len = 4,
	formatNum = function(x, ...) format(x, trim = TRUE, drop0trailing = TRUE, ...))

Arguments

object any object whose structure is displayed compactly.
max.level maximal level of a nesting structure can be displayed. The default is NA, which means all levels of a nesting structure are displayed.
vec.len The suggested number of elements in a vector to display. The actual number of displayed elements depends on the data and the width argument.
digits.d the number of significant digits to display in numeric or complex components. The default is the "digits.d" component of option "str".
nchar.max The maximum number of characters to display for a character string. Longer strings are truncated and the string "| __truncated__" is appended to them.
give.attr a logical value. If TRUE (the default), the attribute(s) of the object and of its subcomponents are shown.
give.head a logical value. If TRUE (the default), the class or mode type (which can be abbreviated) and the length (shown in the form of [1:n]) are shown. (The display of length information is dependent on give.length.)
give.length a logical value. If TRUE, the length information (in the form of [1:n]) is shown when give.head is also TRUE.
width the width of the page. This argument is effective only when strict.width is not "no". The default value is defined by the system option "width".
nest.lev the current nesting level. This argument is used in recursive iteration to show all structures. The default is 0, which indicates the root level.
indent.str the string for indentation. The default string is concatenated with several (nest.lev+1) blanks separated with "..".
comp.str the string to separate the components of the list. The default is "$". Note that the string to separate the slots of an S4 object is "@".
no.list a logical value. If TRUE, no "List of [n]" is shown. The default is FALSE.
envir This argument is not yet implemented. The environment to use for "promise" objects.
strict.width This argument is not yet implemented. A character string that specifies how to handle lines exceeding the page width. Can be one of the following three supported strings:
"no" does nothing on the longer lines.
"wrap" uses the strwrap function for longer lines.
"cut" uses the sub function to cut lines to width.
The default value is the "strict.width" component of the option "str".
formatNum This argument is not yet implemented. A format function for a numeric vector. The default value is the "formatNum" component of option "str".
list.len the maximal number of lists to be shown in a level. If the number of the existing list is greater than this maximum, string "[list output truncated]" is appended.
... other arguments pass to or from methods/functions.

Details

str prints out the compact structure of an object. The output contents are dependent on the object type, mode, or class, and the various combination of input arguments. str is generic; currently it has two hidden methods: the default and for class "data.frame".
strOptions is a convenient function to define the options of "str".
Value
strreturns nothing; it just sends the output to the terminal.
strOptionsreturns a named list of the following options:

  • "strict.width"
  • "digits.d"
  • "vec.len"
  • "formatNum"
Differences between Spotfire Enterprise Runtime for R and Open-source R
See Also
summary, dput, strwrap, format
Examples
ldose <- rep(0:5, 2)
numdead <- c(1, 4, 9, 13, 18, 20, 0, 2, 6, 10, 12, 16)
sex <- factor(rep(c("M", "F"), c(6, 6)))
SF <- cbind(numdead, numalive = 20 - numdead)
x <- glm(SF ~ sex*ldose, family = binomial)
str(x)
str(x, max.level = 2, digits.d = 5, strict.width = "wrap")
str(x, give.attr = FALSE, give.head = FALSE, give.length = TRUE)
str(x, no.list = TRUE, list.len = 6, nchar.max = 3, comp.str = "#")

str(substitute(x))
str(factor)  # factor is a function.
str(Sdatasets::co2)  # co2 is a Time-Series object.
str(Sdatasets::air)  # air is a data frame
str(cbind2) # cbind2 is an S4 object.

#  Example for a "call" object.
funs <- c("sin", "cos")
xx <- 30*pi/180
ii <- 1
my.call <- call(funs[ii], as.name("xx"))
str(my.call)

# Example for "strOptions".
oldOptions <- options(str = strOptions(strict.width = "wrap",
    digits.d = 4, vec.len = 5 ))
str(options())
options(oldOptions)
Package utils version 6.1.1-7
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