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 <williamwdunlap at 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.fabri at
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 at r-project.org mailing list
>> https://stat.ethz.ch/mailman/listinfo/r-devel
>>
>
> [[alternative HTML version deleted]]
>
> ______________________________________________
> R-devel at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-devel
--
benz0li.b-data.io | @benz0li | olivier.benz at b-data.ch