> So in this case, the different results are not due to the architecture (M1 > aka ARM64) but to the system/implementation.
I would say that your results demonstrate that R number parsing code relies on higher-than double precision to perform correct number parsing. Extended precision is not guaranteed by the C standard, so I would classify this as a bug in R. Unless of course R doesn’t want to make any number parsing guarantees, but that would be an odd choice to make :) Cheers, Taras > On 19 Jul 2022, at 14:59, Olivier Benz <olivier.b...@b-data.ch> wrote: > > I found that quite puzzling indeed. Thanks for the references. > > So in this case, the different results are not due to the architecture (M1 > aka ARM64) but to the system/implementation. > >> On 19 Jul 2022, at 14:22, Taras Zakharko <taras.zakha...@uzh.ch >> <mailto:taras.zakha...@uzh.ch>> wrote: >> >> Just a quick note of this in case someone finds Olivier's results puzzling. >> Standard ARM64 ABI (which Linux follows) defines long double as a 16-byte >> extended precision type. LLVM’s compiler-rt has a software implementation >> for doing operations on such types. Apple instead defines long double as >> identical to double in their ABIs. >> >> References >> >> https://developer.arm.com/documentation/ka004751/1-0 >> >> https://developer.apple.com/documentation/xcode/writing-arm64-code-for-apple-platforms >> >> >> >> >>> On 19 Jul 2022, at 13:04, Olivier Benz <olivier.b...@b-data.ch> wrote: >>> >>> The difference between macOS 12.4 and Debian 11 (Docker, virtualization >>> framework) running on a MacBook Pro (M1 Max). >>> -> `.Machine$sizeof.longdouble` on macOS returns 8 whereas on Debian 11 it >>> returns 16. >>> >>> macOS 12.4 on MacBook Pro (M1 Max): >>> ``` r >>> .Machine >>> #> $double.eps >>> #> [1] 2.220446e-16 >>> #> >>> #> $double.neg.eps >>> #> [1] 1.110223e-16 >>> #> >>> #> $double.xmin >>> #> [1] 2.225074e-308 >>> #> >>> #> $double.xmax >>> #> [1] 1.797693e+308 >>> #> >>> #> $double.base >>> #> [1] 2 >>> #> >>> #> $double.digits >>> #> [1] 53 >>> #> >>> #> $double.rounding >>> #> [1] 5 >>> #> >>> #> $double.guard >>> #> [1] 0 >>> #> >>> #> $double.ulp.digits >>> #> [1] -52 >>> #> >>> #> $double.neg.ulp.digits >>> #> [1] -53 >>> #> >>> #> $double.exponent >>> #> [1] 11 >>> #> >>> #> $double.min.exp >>> #> [1] -1022 >>> #> >>> #> $double.max.exp >>> #> [1] 1024 >>> #> >>> #> $integer.max >>> #> [1] 2147483647 >>> #> >>> #> $sizeof.long >>> #> [1] 8 >>> #> >>> #> $sizeof.longlong >>> #> [1] 8 >>> #> >>> #> $sizeof.longdouble >>> #> [1] 8 >>> #> >>> #> $sizeof.pointer >>> #> [1] 8 >>> >>> bitC <- function(x) noquote(vapply(as.double(x), function(x) { # split one >>> double >>> b <- substr(as.character(rev(numToBits(x))), 2L, 2L) >>> paste0(c(b[1L], " ", b[2:12], " | ", b[13:64]), collapse = "") >>> }, "")) >>> bitC(10^25) >>> #> [1] 0 10001010010 | 0000100010110010101000101100001010000000001010010001 >>> bitC(10000000000000000905969664) >>> #> [1] 0 10001010010 | 0000100010110010101000101100001010000000001010010010 >>> bitC(10000000000000000905969664 - 10^25) >>> #> [1] 0 10000011110 | 0000000000000000000000000000000000000000000000000000 >>> bitC(1e25) >>> #> [1] 0 10001010010 | 0000100010110010101000101100001010000000001010010001 >>> ``` >>> >>> <sup>Created on 2022-07-19 by the [reprex >>> package](https://reprex.tidyverse.org) (v2.0.1)</sup> >>> >>> <details style="margin-bottom:10px;"> >>> <summary> >>> Session info >>> </summary> >>> >>> ``` r >>> sessioninfo::session_info() >>> #> ─ Session info >>> ─────────────────────────────────────────────────────────────── >>> #> setting value >>> #> version R version 4.2.1 (2022-06-23) >>> #> os macOS Monterey 12.4 >>> #> system aarch64, darwin20 >>> #> ui X11 >>> #> language (EN) >>> #> collate en_US.UTF-8 >>> #> ctype UTF-8 >>> #> tz Europe/Copenhagen >>> #> date 2022-07-19 >>> #> pandoc 2.18 @ /opt/local/bin/ (via rmarkdown) >>> #> >>> #> ─ Packages >>> ─────────────────────────────────────────────────────────────────── >>> #> package * version date (UTC) lib source >>> #> cli 3.3.0 2022-04-25 [1] CRAN (R 4.2.0) >>> #> digest 0.6.29 2021-12-01 [1] CRAN (R 4.2.0) >>> #> ellipsis 0.3.2 2021-04-29 [1] CRAN (R 4.2.0) >>> #> evaluate 0.15 2022-02-18 [1] CRAN (R 4.2.0) >>> #> fansi 1.0.3 2022-03-24 [1] CRAN (R 4.2.0) >>> #> fastmap 1.1.0 2021-01-25 [1] CRAN (R 4.2.0) >>> #> fs 1.5.2 2021-12-08 [1] CRAN (R 4.2.0) >>> #> glue 1.6.2 2022-02-24 [1] CRAN (R 4.2.0) >>> #> highr 0.9 2021-04-16 [1] CRAN (R 4.2.0) >>> #> htmltools 0.5.3 2022-07-18 [1] CRAN (R 4.2.1) >>> #> knitr 1.39 2022-04-26 [1] CRAN (R 4.2.0) >>> #> lifecycle 1.0.1 2021-09-24 [1] CRAN (R 4.2.0) >>> #> magrittr 2.0.3 2022-03-30 [1] CRAN (R 4.2.0) >>> #> pillar 1.8.0 2022-07-18 [1] CRAN (R 4.2.1) >>> #> pkgconfig 2.0.3 2019-09-22 [1] CRAN (R 4.2.0) >>> #> purrr 0.3.4 2020-04-17 [1] CRAN (R 4.2.0) >>> #> R.cache 0.15.0 2021-04-30 [1] CRAN (R 4.2.0) >>> #> R.methodsS3 1.8.2 2022-06-13 [1] CRAN (R 4.2.0) >>> #> R.oo 1.25.0 2022-06-12 [1] CRAN (R 4.2.0) >>> #> R.utils 2.12.0 2022-06-28 [1] CRAN (R 4.2.0) >>> #> reprex 2.0.1 2021-08-05 [1] CRAN (R 4.2.0) >>> #> rlang 1.0.4 2022-07-12 [1] CRAN (R 4.2.1) >>> #> rmarkdown 2.14 2022-04-25 [1] CRAN (R 4.2.0) >>> #> sessioninfo 1.2.2 2021-12-06 [1] CRAN (R 4.2.0) >>> #> stringi 1.7.8 2022-07-11 [1] CRAN (R 4.2.1) >>> #> stringr 1.4.0 2019-02-10 [1] CRAN (R 4.2.0) >>> #> styler 1.7.0 2022-03-13 [1] CRAN (R 4.2.0) >>> #> tibble 3.1.7 2022-05-03 [1] CRAN (R 4.2.0) >>> #> utf8 1.2.2 2021-07-24 [1] CRAN (R 4.2.0) >>> #> vctrs 0.4.1 2022-04-13 [1] CRAN (R 4.2.0) >>> #> withr 2.5.0 2022-03-03 [1] CRAN (R 4.2.0) >>> #> xfun 0.31 2022-05-10 [1] CRAN (R 4.2.0) >>> #> yaml 2.3.5 2022-02-21 [1] CRAN (R 4.2.0) >>> #> >>> #> [1] /Users/benz0li/Library/R/arm64/4.2/library >>> #> [2] /Library/Frameworks/R.framework/Versions/4.2-arm64/Resources/library >>> #> >>> #> >>> ────────────────────────────────────────────────────────────────────────────── >>> ``` >>> >>> </details> >>> >>> Debian 11 (Docker, virtualization framework) on MacBook Pro (M1 Max) >>> ``` r >>> .Machine >>> #> $double.eps >>> #> [1] 2.220446e-16 >>> #> >>> #> $double.neg.eps >>> #> [1] 1.110223e-16 >>> #> >>> #> $double.xmin >>> #> [1] 2.225074e-308 >>> #> >>> #> $double.xmax >>> #> [1] 1.797693e+308 >>> #> >>> #> $double.base >>> #> [1] 2 >>> #> >>> #> $double.digits >>> #> [1] 53 >>> #> >>> #> $double.rounding >>> #> [1] 5 >>> #> >>> #> $double.guard >>> #> [1] 0 >>> #> >>> #> $double.ulp.digits >>> #> [1] -52 >>> #> >>> #> $double.neg.ulp.digits >>> #> [1] -53 >>> #> >>> #> $double.exponent >>> #> [1] 11 >>> #> >>> #> $double.min.exp >>> #> [1] -1022 >>> #> >>> #> $double.max.exp >>> #> [1] 1024 >>> #> >>> #> $integer.max >>> #> [1] 2147483647 >>> #> >>> #> $sizeof.long >>> #> [1] 8 >>> #> >>> #> $sizeof.longlong >>> #> [1] 8 >>> #> >>> #> $sizeof.longdouble >>> #> [1] 16 >>> #> >>> #> $sizeof.pointer >>> #> [1] 8 >>> #> >>> #> $longdouble.eps >>> #> [1] 1.92593e-34 >>> #> >>> #> $longdouble.neg.eps >>> #> [1] 9.62965e-35 >>> #> >>> #> $longdouble.digits >>> #> [1] 113 >>> #> >>> #> $longdouble.rounding >>> #> [1] 5 >>> #> >>> #> $longdouble.guard >>> #> [1] 0 >>> #> >>> #> $longdouble.ulp.digits >>> #> [1] -112 >>> #> >>> #> $longdouble.neg.ulp.digits >>> #> [1] -113 >>> #> >>> #> $longdouble.exponent >>> #> [1] 15 >>> #> >>> #> $longdouble.min.exp >>> #> [1] -16382 >>> #> >>> #> $longdouble.max.exp >>> #> [1] 16384 >>> >>> bitC <- function(x) noquote(vapply(as.double(x), function(x) { # split one >>> double >>> b <- substr(as.character(rev(numToBits(x))), 2L, 2L) >>> paste0(c(b[1L], " ", b[2:12], " | ", b[13:64]), collapse = "") >>> }, "")) >>> bitC(10^25) >>> #> [1] 0 10001010010 | 0000100010110010101000101100001010000000001010010001 >>> bitC(10000000000000000905969664) >>> #> [1] 0 10001010010 | 0000100010110010101000101100001010000000001010010001 >>> bitC(10000000000000000905969664 - 10^25) >>> #> [1] 0 00000000000 | 0000000000000000000000000000000000000000000000000000 >>> bitC(1e25) >>> #> [1] 0 10001010010 | 0000100010110010101000101100001010000000001010010001 >>> ``` >>> >>> <sup>Created on 2022-07-19 by the [reprex >>> package](https://reprex.tidyverse.org) (v2.0.1)</sup> >>> >>> <details style="margin-bottom:10px;"> >>> <summary> >>> Session info >>> </summary> >>> >>> ``` r >>> sessioninfo::session_info() >>> #> ─ Session info >>> ─────────────────────────────────────────────────────────────── >>> #> setting value >>> #> version R version 4.2.1 (2022-06-23) >>> #> os Debian GNU/Linux 11 (bullseye) >>> #> system aarch64, linux-gnu >>> #> ui X11 >>> #> language (EN) >>> #> collate en_US.UTF-8 >>> #> ctype en_US.UTF-8 >>> #> tz Etc/UTC >>> #> date 2022-07-19 >>> #> pandoc 2.18 @ /usr/bin/ (via rmarkdown) >>> #> >>> #> ─ Packages >>> ─────────────────────────────────────────────────────────────────── >>> #> package * version date (UTC) lib source >>> #> cli 3.3.0 2022-04-25 [2] CRAN (R 4.2.1) >>> #> crayon 1.5.1 2022-03-26 [2] CRAN (R 4.2.1) >>> #> digest 0.6.29 2021-12-01 [2] CRAN (R 4.2.1) >>> #> ellipsis 0.3.2 2021-04-29 [2] CRAN (R 4.2.1) >>> #> evaluate 0.15 2022-02-18 [2] CRAN (R 4.2.1) >>> #> fansi 1.0.3 2022-03-24 [2] CRAN (R 4.2.1) >>> #> fastmap 1.1.0 2021-01-25 [2] CRAN (R 4.2.1) >>> #> fs 1.5.2 2021-12-08 [2] CRAN (R 4.2.1) >>> #> glue 1.6.2 2022-02-24 [2] CRAN (R 4.2.1) >>> #> highr 0.9 2021-04-16 [2] CRAN (R 4.2.1) >>> #> htmltools 0.5.2 2021-08-25 [2] CRAN (R 4.2.1) >>> #> knitr 1.39 2022-04-26 [2] CRAN (R 4.2.1) >>> #> lifecycle 1.0.1 2021-09-24 [2] CRAN (R 4.2.1) >>> #> magrittr 2.0.3 2022-03-30 [2] CRAN (R 4.2.1) >>> #> pillar 1.7.0 2022-02-01 [2] CRAN (R 4.2.1) >>> #> pkgconfig 2.0.3 2019-09-22 [2] CRAN (R 4.2.1) >>> #> purrr 0.3.4 2020-04-17 [2] CRAN (R 4.2.1) >>> #> R.cache 0.15.0 2021-04-30 [2] CRAN (R 4.2.1) >>> #> R.methodsS3 1.8.2 2022-06-13 [2] CRAN (R 4.2.1) >>> #> R.oo 1.25.0 2022-06-12 [2] CRAN (R 4.2.1) >>> #> R.utils 2.12.0 2022-06-28 [2] CRAN (R 4.2.1) >>> #> reprex 2.0.1 2021-08-05 [2] CRAN (R 4.2.1) >>> #> rlang 1.0.4 2022-07-12 [2] CRAN (R 4.2.1) >>> #> rmarkdown 2.14 2022-04-25 [2] CRAN (R 4.2.1) >>> #> sessioninfo 1.2.2 2021-12-06 [2] CRAN (R 4.2.1) >>> #> stringi 1.7.8 2022-07-11 [2] CRAN (R 4.2.1) >>> #> stringr 1.4.0 2019-02-10 [2] CRAN (R 4.2.1) >>> #> styler 1.7.0 2022-03-13 [2] CRAN (R 4.2.1) >>> #> tibble 3.1.7 2022-05-03 [2] CRAN (R 4.2.1) >>> #> utf8 1.2.2 2021-07-24 [2] CRAN (R 4.2.1) >>> #> vctrs 0.4.1 2022-04-13 [2] CRAN (R 4.2.1) >>> #> withr 2.5.0 2022-03-03 [2] CRAN (R 4.2.1) >>> #> xfun 0.31 2022-05-10 [2] CRAN (R 4.2.1) >>> #> yaml 2.3.5 2022-02-21 [2] CRAN (R 4.2.1) >>> #> >>> #> [1] /home/benz0li/R/aarch64-unknown-linux-gnu-library/4.2 >>> #> [2] /usr/local/lib/R/site-library >>> #> [3] /usr/local/lib/R/library >>> #> >>> #> >>> ────────────────────────────────────────────────────────────────────────────── >>> ``` >>> >>> </details> >>> >>>> On 10 Jul 2022, at 22:23, Bill Dunlap <williamwdun...@gmail.com> wrote: >>>> >>>> The following function, 'bitC' from ?numToBits, displays the bits in a >>>> double precision number, separated into the sign bit, the 11 exponent bits, >>>> and the 52 bits in the mantissa. I've shown the results with your numbers >>>> from R-2.4.0 on my Windows 11 Lenovo laptop: what do you get? >>>> >>>>> bitC <- function(x) noquote(vapply(as.double(x), function(x) { # split >>>> one double >>>> + b <- substr(as.character(rev(numToBits(x))), 2L, 2L) >>>> + paste0(c(b[1L], " ", b[2:12], " | ", b[13:64]), collapse = "") >>>> + }, "")) >>>>> bitC(10^25) >>>> # [1] 0 10001010010 | 0000100010110010101000101100001010000000001010010001 >>>>> bitC(10000000000000000905969664) >>>> # [1] 0 10001010010 | 0000100010110010101000101100001010000000001010010001 >>>>> bitC(10000000000000000905969664 - 10^25) >>>> # [1] 0 00000000000 | 0000000000000000000000000000000000000000000000000000 >>>>> bitC(1e25) >>>> # [1] 0 10001010010 | 0000100010110010101000101100001010000000001010010001 >>>> >>>> -Bill >>>> >>>> On Sun, Jul 10, 2022 at 7:00 AM Antoine Fabri <antoine.fa...@gmail.com> >>>> wrote: >>>> >>>>> Dear r-devel, >>>>> >>>>> For some numbers, the printed value is not equivalent to the input : >>>>> >>>>> options(scipen = 999) >>>>> ## GOOD >>>>> 1e24 >>>>> #> [1] 999999999999999983222784 >>>>> 1e24 == 999999999999999983222784 >>>>> #> [1] TRUE >>>>> >>>>> ## BAD >>>>> 1e25 >>>>> #> [1] 10000000000000000905969664 >>>>> 1e25 == 10000000000000000905969664 >>>>> #> [1] FALSE >>>>> >>>>> ## STILL BAD >>>>> 10000000000000000905969664 >>>>> #> [1] 10000000000000003053453312 >>>>> >>>>> ## GOOD AGAIN >>>>> 10000000000000003053453312 >>>>> #> [1] 10000000000000003053453312 >>>>> >>>>> # Additionally >>>>> 10000000000000000000000000 == 1e25 >>>>> #> [1] FALSE >>>>> >>>>> Are these bugs ? >>>>> >>>>> [[alternative HTML version deleted]] >>>>> >>>>> ______________________________________________ >>>>> R-devel@r-project.org mailing list >>>>> https://stat.ethz.ch/mailman/listinfo/r-devel >>>>> >>>> >>>> [[alternative HTML version deleted]] >>>> >>>> ______________________________________________ >>>> R-devel@r-project.org mailing list >>>> https://stat.ethz.ch/mailman/listinfo/r-devel >>> >>> -- >>> benz0li.b-data.io | @benz0li | olivier.b...@b-data.ch >>> >>> ______________________________________________ >>> R-devel@r-project.org mailing list >>> https://stat.ethz.ch/mailman/listinfo/r-devel >> >> >> [[alternative HTML version deleted]] >> >> ______________________________________________ >> R-devel@r-project.org <mailto:R-devel@r-project.org> mailing list >> https://stat.ethz.ch/mailman/listinfo/r-devel > > -- > benz0li.b-data.io <http://benz0li.b-data.io/> | @benz0li | > olivier.b...@b-data.ch <mailto:olivier.b...@b-data.ch> [[alternative HTML version deleted]] ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel