I believe this to be a false report. It is *printing* that rounds off the
numbers, not the reading.
You provide no evidence of your assertions: here is a simple counter-example:
> A <- data.frame(a=12.4283675334551)
> write.table(A, "foo")
> AA <- read.table("foo")
> A
a
1 12.42837
> AA
a
1 12.42837
> print(AA, digits=16)
a
1 12.4283675334551
> AA-A
a
1 0
The last just happens to be true in this example, as there would normally
be a small representation error.
On Tue, 13 Jun 2006, [EMAIL PROTECTED] wrote:
> Full_Name: Aart Overeem
> Version: 2.2.0
You are explicitly instructed to upgrade before reporting a bug.
> OS: Linux
> Submission from: (NULL) (145.23.254.155)
>
>
> Construct a dataframe consisting of several variables by using
> 'data.frame' and 'cbind' and write it to a file with 'write.table'. The
> file consists of headers and values, such as 12.4283675334551 (so 13
> numbers behind the decimal point).
That is, 15 significant digits.
> If this dataframe is read with 'read.table(filename, skip = 1)' or
> 'read.table(filename, header = TRUE') the values only have 7 numbers
> behind the decimal point, e.g. 12.42837.
Your example has *five*, and is printed to 7 significant digits, the
default for printing.
> So, the reading rounds off the values. This is not mentioned in the
> manual. Although the values still have many numbers behind the decimal
> point, rounding off is, in my view, never desirable.
Nor is submitting false reports.
--
Brian D. Ripley, [EMAIL PROTECTED]
Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/
University of Oxford, Tel: +44 1865 272861 (self)
1 South Parks Road, +44 1865 272866 (PA)
Oxford OX1 3TG, UK Fax: +44 1865 272595
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