[Rd] number formsat
Simon Urbanek
simon.urbanek at r-project.org
Thu Feb 14 23:59:53 CET 2008
Hill0093,
On Feb 14, 2008, at 5:43 PM, hill0093 wrote:
> PROBLEM ONE
> In my way of using R in print and plots,
> R severely ignores formatting requests for numbers.
> E.g.,
>> n1=2008021323595999
>> n1
> [1] 2.008021e+15
>> print(n1,digits=16)
> [1] 2008021323595999
>> print(n1,digits=18)
> [1] 2008021323595999
>> print(n1,digits=15)
> [1] 2008021323595999
You are not requesting specific formatting, you are requesting
*significant digits* hence the above is as expected. For output
formatting, see ?sprintf and ?formatC.
> The e+15 form for similar numbers also appears in the tic mark
> labels in plots, but with yet other counts of significant digits.
> PROBLEM TWO
> I need to use a function that I could write, since I have done it in
> several other languages, to convert my calendar times of various
> lengths into linear time as I read the data. Then I need to use an
> inverse function to convert the linear time for the tic mark labels
> of plots of the data, and for printouts.
> Where do I look to learn how to do this in R?
>
Time types in R are linear, try using them (see ?DateTimeClasses and ?
as.POSIXct).
Please post help requests to R-help in the future.
Thanks,
Simon
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