[R] Writing to a file with fixed precision

[Marc Schwartz]

On Tue, 2005-10-11 at 08:42 +0100, Prof Brian Ripley wrote:
> On Mon, 10 Oct 2005, Marc Schwartz wrote:
> 
> > On Mon, 2005-10-10 at 19:50 -0400, Richard Hedger wrote:
> >> Hi,
> >> I'm trying to ouput to a filled with a fixed precision:
> >> eg. if I have data x=c(1.0,1.4,2.0), I want to be able to ouput the following to a file:
> >> 1.00000000000000
> >> 1.40000000000000
> >> 2.00000000000000
> >> I was wondering if there was a function to do this in R?
> >> Thanks,
> >> Richard
> >
> > It is possible that someone has written such a function somewhere.
> 
> It's called format().
> 
> x <- c(1.0,1.4,2.0)
> write(format(x, nsmall=14))
> 
> does this.

Indeed. Sorry, I was not clear in my use of words. I was thinking along
the lines of a single function call such as:

  write.fmt(x, file = "data.txt", ndigits = 14)

It would of course be easy enough to create such a wrapper using
existing functions.

I was aware of format(), but for some reason had in the back of my mind
that the use of 'nsmall' was not consistent in the decimal place output
based upon prior experience.

The result of which led me to use the vectorized formatC() to control
such output. I then shifted to using sprintf(), when in 2.1.0, it was
vectorized.

Using format() also adds the benefit of having methods for matrices,
etc., as opposed to sprintf().

Thanks,

Marc