Imanuel Costigan
2013-Oct-04 10:11 UTC
[Rd] Possible POSIXlt / wday glitch & bugs.r-project.org status
Wanted to raise two questions: 1. Is bugs.r-project.org down? I haven't been able to reach it for two or three days: ``` ping bugs.r-project.org PING rbugs.research.att.com (207.140.168.137): 56 data bytes Request timeout for icmp_seq 0 Request timeout for icmp_seq 1 Request timeout for icmp_seq 2 Request timeout for icmp_seq 3 Request timeout for icmp_seq 4 Request timeout for icmp_seq 5 Request timeout for icmp_seq 6 ``` 2. Is wday element of POSIXlt meant to be timezone invariant? You would expect the wday element to be invariant to the timezone of a date. That is, the same date/time instant of 5th October 2013 in both Australia/Sydney and UTC should be a Saturday (i.e. wday = 6). And indeed that is the case with 1 min past midnight on 5 October 2013: ``` library(lubridate) d_utc <- ymd_hms(20131005000001, tz='UTC') d_local <- ymd_hms(20131005000001, tz='Australia/Sydney') as.POSIXlt(x=d_utc, tz=tz(d_utc))$wday # 6 as.POSIXlt(x=d_local, tz=tz(d_local))$wday # 6 ``` But this isn't always the case. For example, ``` d_utc <- ymd_hms(20381002000001, tz='UTC') d_local <- ymd_hms(20381002000001, tz='Australia/Sydney') as.POSIXlt(x=d_utc, tz=tz(d_utc))$wday # 6 as.POSIXlt(x=d_local, tz=tz(d_local))$wday # 5 ``` Is this expected behaviour? I would have expected a properly encoded date/time of 2 Oct 2038 to be a Saturday irrespective of its time zone. Obligatory system dump: ```> sessionInfo()R version 3.0.1 (2013-05-16) Platform: x86_64-apple-darwin12.4.0 (64-bit) locale: [1] en_AU.UTF-8/en_AU.UTF-8/en_AU.UTF-8/C/en_AU.UTF-8/en_AU.UTF-8 attached base packages: [1] stats graphics grDevices utils datasets methods base other attached packages: [1] lubridate_1.3.0 testthat_0.7.1 devtools_1.3 loaded via a namespace (and not attached): [1] colorspace_1.2-4 dichromat_2.0-0 digest_0.6.3 evaluate_0.5.1 [5] ggplot2_0.9.3.1 grid_3.0.1 gtable_0.1.2 httr_0.2 [9] labeling_0.2 MASS_7.3-29 memoise_0.1 munsell_0.4.2 [13] parallel_3.0.1 plyr_1.8 proto_0.3-10 RColorBrewer_1.0-5 [17] RCurl_1.95-4.1 reshape2_1.2.2 scales_0.2.3 stringr_0.6.2 [21] tools_3.0.1 whisker_0.3-2 ``` Using R compiled by homebrew [1]. But also experiencing the same bug using R installed on Windows 7 from the CRAN binaries. For those interested, I've also noted this on the `lubridate` Github issues page [2], even though this doesn't appear to be a lubridate issue. Thanks for any help. [1] http://brew.sh [2] https://github.com/hadley/lubridate/issues/209
Joshua Ulrich
2013-Oct-04 12:50 UTC
[Rd] Possible POSIXlt / wday glitch & bugs.r-project.org status
Quoting from ?timezone:
Note that except on Windows, the operation of time zones is an OS
service, and even on Windows a third-party database is used and
can be updated (see the section on ?Time zone names?). Incorrect
results will never be an R issue, so please ensure that you have
the courtesy not to blame R for them.
Best,
--
Joshua Ulrich | about.me/joshuaulrich
FOSS Trading | www.fosstrading.com
On Fri, Oct 4, 2013 at 5:11 AM, Imanuel Costigan <i.costigan at me.com>
wrote:> Wanted to raise two questions:
>
> 1. Is bugs.r-project.org down? I haven't been able to reach it for two
or three days:
>
> ```
> ping bugs.r-project.org
> PING rbugs.research.att.com (207.140.168.137): 56 data bytes
> Request timeout for icmp_seq 0
> Request timeout for icmp_seq 1
> Request timeout for icmp_seq 2
> Request timeout for icmp_seq 3
> Request timeout for icmp_seq 4
> Request timeout for icmp_seq 5
> Request timeout for icmp_seq 6
> ```
>
> 2. Is wday element of POSIXlt meant to be timezone invariant? You would
expect the wday element to be invariant to the timezone of a date. That is, the
same date/time instant of 5th October 2013 in both Australia/Sydney and UTC
should be a Saturday (i.e. wday = 6). And indeed that is the case with 1 min
past midnight on 5 October 2013:
>
> ```
> library(lubridate)
> d_utc <- ymd_hms(20131005000001, tz='UTC')
> d_local <- ymd_hms(20131005000001, tz='Australia/Sydney')
> as.POSIXlt(x=d_utc, tz=tz(d_utc))$wday # 6
> as.POSIXlt(x=d_local, tz=tz(d_local))$wday # 6
> ```
>
> But this isn't always the case. For example,
>
> ```
> d_utc <- ymd_hms(20381002000001, tz='UTC')
> d_local <- ymd_hms(20381002000001, tz='Australia/Sydney')
> as.POSIXlt(x=d_utc, tz=tz(d_utc))$wday # 6
> as.POSIXlt(x=d_local, tz=tz(d_local))$wday # 5
> ```
>
> Is this expected behaviour? I would have expected a properly encoded
date/time of 2 Oct 2038 to be a Saturday irrespective of its time zone.
>
> Obligatory system dump:
>
> ```
>> sessionInfo()
> R version 3.0.1 (2013-05-16)
> Platform: x86_64-apple-darwin12.4.0 (64-bit)
>
> locale:
> [1] en_AU.UTF-8/en_AU.UTF-8/en_AU.UTF-8/C/en_AU.UTF-8/en_AU.UTF-8
>
> attached base packages:
> [1] stats graphics grDevices utils datasets methods base
>
> other attached packages:
> [1] lubridate_1.3.0 testthat_0.7.1 devtools_1.3
>
> loaded via a namespace (and not attached):
> [1] colorspace_1.2-4 dichromat_2.0-0 digest_0.6.3
evaluate_0.5.1
> [5] ggplot2_0.9.3.1 grid_3.0.1 gtable_0.1.2 httr_0.2
> [9] labeling_0.2 MASS_7.3-29 memoise_0.1 munsell_0.4.2
> [13] parallel_3.0.1 plyr_1.8 proto_0.3-10
RColorBrewer_1.0-5
> [17] RCurl_1.95-4.1 reshape2_1.2.2 scales_0.2.3 stringr_0.6.2
> [21] tools_3.0.1 whisker_0.3-2
>
> ```
>
> Using R compiled by homebrew [1]. But also experiencing the same bug using
R installed on Windows 7 from the CRAN binaries.
>
> For those interested, I've also noted this on the `lubridate` Github
issues page [2], even though this doesn't appear to be a lubridate issue.
>
> Thanks for any help.
>
> [1] http://brew.sh
> [2] https://github.com/hadley/lubridate/issues/209
>
> ______________________________________________
> R-devel at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-devel
Scott Kostyshak
2013-Oct-04 14:59 UTC
[Rd] Possible POSIXlt / wday glitch & bugs.r-project.org status
On Fri, Oct 4, 2013 at 6:11 AM, Imanuel Costigan <i.costigan at me.com> wrote:> Wanted to raise two questions: > > 1. Is bugs.r-project.org down? I haven't been able to reach it for two or three days:Yes. Quote from Duncan: ... the server is currently down. The volunteer who runs the server is currently away from his office, so I expect it won't get fixed until he gets back in a few days. https://stat.ethz.ch/pipermail/r-help/2013-October/360958.html Scott> > ``` > ping bugs.r-project.org > PING rbugs.research.att.com (207.140.168.137): 56 data bytes > Request timeout for icmp_seq 0 > Request timeout for icmp_seq 1 > Request timeout for icmp_seq 2 > Request timeout for icmp_seq 3 > Request timeout for icmp_seq 4 > Request timeout for icmp_seq 5 > Request timeout for icmp_seq 6 > ``` > > 2. Is wday element of POSIXlt meant to be timezone invariant? You would expect the wday element to be invariant to the timezone of a date. That is, the same date/time instant of 5th October 2013 in both Australia/Sydney and UTC should be a Saturday (i.e. wday = 6). And indeed that is the case with 1 min past midnight on 5 October 2013: > > ``` > library(lubridate) > d_utc <- ymd_hms(20131005000001, tz='UTC') > d_local <- ymd_hms(20131005000001, tz='Australia/Sydney') > as.POSIXlt(x=d_utc, tz=tz(d_utc))$wday # 6 > as.POSIXlt(x=d_local, tz=tz(d_local))$wday # 6 > ``` > > But this isn't always the case. For example, > > ``` > d_utc <- ymd_hms(20381002000001, tz='UTC') > d_local <- ymd_hms(20381002000001, tz='Australia/Sydney') > as.POSIXlt(x=d_utc, tz=tz(d_utc))$wday # 6 > as.POSIXlt(x=d_local, tz=tz(d_local))$wday # 5 > ``` > > Is this expected behaviour? I would have expected a properly encoded date/time of 2 Oct 2038 to be a Saturday irrespective of its time zone. > > Obligatory system dump: > > ``` >> sessionInfo() > R version 3.0.1 (2013-05-16) > Platform: x86_64-apple-darwin12.4.0 (64-bit) > > locale: > [1] en_AU.UTF-8/en_AU.UTF-8/en_AU.UTF-8/C/en_AU.UTF-8/en_AU.UTF-8 > > attached base packages: > [1] stats graphics grDevices utils datasets methods base > > other attached packages: > [1] lubridate_1.3.0 testthat_0.7.1 devtools_1.3 > > loaded via a namespace (and not attached): > [1] colorspace_1.2-4 dichromat_2.0-0 digest_0.6.3 evaluate_0.5.1 > [5] ggplot2_0.9.3.1 grid_3.0.1 gtable_0.1.2 httr_0.2 > [9] labeling_0.2 MASS_7.3-29 memoise_0.1 munsell_0.4.2 > [13] parallel_3.0.1 plyr_1.8 proto_0.3-10 RColorBrewer_1.0-5 > [17] RCurl_1.95-4.1 reshape2_1.2.2 scales_0.2.3 stringr_0.6.2 > [21] tools_3.0.1 whisker_0.3-2 > > ``` > > Using R compiled by homebrew [1]. But also experiencing the same bug using R installed on Windows 7 from the CRAN binaries. > > For those interested, I've also noted this on the `lubridate` Github issues page [2], even though this doesn't appear to be a lubridate issue. > > Thanks for any help. > > [1] http://brew.sh > [2] https://github.com/hadley/lubridate/issues/209 > > ______________________________________________ > R-devel at r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-devel-- Scott Kostyshak Economics PhD Candidate Princeton University