| format.info {base} | R Documentation | 
Information is returned on how format(x, digits, nsmall)
would be formatted.
format.info(x, digits = NULL, nsmall = 0)
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)). | 
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.
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,w=1,dig=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)