format.info               package:base               R Documentation

format(.) Information

Description:

     Information is returned on how 'format(x, digits, nsmall)' would
     be formatted.

Usage:

     format.info(x, digits = NULL, nsmall = 0)

Arguments:

       x: an atomic vector; a potential argument of 'format(x, ...)'.

  digits: how many significant digits are to be used for numeric and
          complex 'x'.  The default, 'NULL', uses 'getOption(digits)'.

  nsmall: (see 'format(..., nsmall)').

Value:

     An 'integer' 'vector' of length 1, 3 or 6, say 'r'.

     For logical, integer and character vectors a single element, the
     width which would be used by 'format' if 'width = NULL'.

     For numeric vectors: 

    r[1]: width (in characters) used by 'format(x)'

    r[2]: number of digits after decimal point.

    r[3]: in '0:2'; if >='1', _exponential_ representation would be
          used, with exponent length of 'r[3]+1'.


     For a complex vector the first three elements refer to the real
     parts, and there are three further elements corresponding to the
     imaginary parts.

See Also:

     'format', 'formatC'.

Examples:

     dd <- options("digits") ; options(digits = 7) #-- for the following
     format.info(123)   # 3 0 0
     format.info(pi)    # 8 6 0
     format.info(1e8)   # 5 0 1 - exponential "1e+08"
     format.info(1e222) # 6 0 2 - exponential "1e+222"

     x <- pi*10^c(-10,-2,0:2,8,20)
     names(x) <- formatC(x, width=1, digits=3, format="g")
     cbind(sapply(x,format))
     t(sapply(x, format.info))

     ## using at least 8 digits right of "."
     t(sapply(x, format.info, nsmall = 8))

     # Reset old options:
     options(dd)

