[Rd] numerics from a factor
maechler at stat.math.ethz.ch
Tue Mar 19 17:30:45 CET 2013
>>>>> Ulrike Grömping <groemping at bht-berlin.de>
>>>>> on Sat, 16 Mar 2013 13:04:07 +0100 writes:
> Hi Terry, you can use type.convert instead of as.numeric
> for numbers with decimals:
> type.convert(levels(factor(1:6/2)), dec=unlist(options("OutDec")))
> Best, Ulrike
a late and minor remark: If you use the above, a slightly more expressive
preferred way is
type.convert(levels(factor(1:6/2)), dec = getOption("OutDec"))
> Am 16.03.2013 12:00, schrieb r-devel-request at r-project.org:
>> A problem has been pointed out by a French user of the survival package and I'm looking
>> for a pointer.
>> > options(OutDec= ",")
>> > fit <- survfit(Surv(1:6 /2) ~ 1)
>> > fit$time
>>  NA 1 NA 2 NA 3
>> A year or two ago some test cases that broke survfit were presented to me. The heart of
>> the problem was numbers that were almost identical, where table(x) and unique(x) gave
>> different counts of distinct values.
>> The solution was to use "ftime <- factor(time)" at the top of the code, and do all the
>> calulations using the integer levels of the factor as the unique time points. At the very
>> end the numeric component "time" of the result is created using
>> as.numeric(levels(ftime)). It's this last line that breaks.
>> I could set the OutDec option within survfit and reset when I leave using on.exit. Any
>> other simple solutions? Any other ways I could get caught by this issue?
>> Terry Therneau
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