* (inf) min max @ 2021-09-28 8:15 Stefan Israelsson Tampe 2021-09-28 8:31 ` tomas 0 siblings, 1 reply; 5+ messages in thread From: Stefan Israelsson Tampe @ 2021-09-28 8:15 UTC (permalink / raw) To: guile-devel [-- Attachment #1: Type: text/plain, Size: 37 bytes --] Why is (min (inf) 1) = 1.0 inexact? [-- Attachment #2: Type: text/html, Size: 75 bytes --] ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: (inf) min max 2021-09-28 8:15 (inf) min max Stefan Israelsson Tampe @ 2021-09-28 8:31 ` tomas 2021-09-28 9:55 ` Stefan Israelsson Tampe 0 siblings, 1 reply; 5+ messages in thread From: tomas @ 2021-09-28 8:31 UTC (permalink / raw) To: guile-devel [-- Attachment #1: Type: text/plain, Size: 375 bytes --] On Tue, Sep 28, 2021 at 10:15:30AM +0200, Stefan Israelsson Tampe wrote: > Why is (min (inf) 1) = 1.0 inexact? Because inf's result is inexact. The same as (min 3 3.5) is inexact, too. It seems that the `inexactness' is contagious across arithmetic generics (I haven't found an explicit place in the Guile docs; the racket docs are more explicit about that). Cheers - t [-- Attachment #2: Digital signature --] [-- Type: application/pgp-signature, Size: 198 bytes --] ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: (inf) min max 2021-09-28 8:31 ` tomas @ 2021-09-28 9:55 ` Stefan Israelsson Tampe 2021-09-28 10:33 ` tomas 2021-09-28 12:00 ` Mikael Djurfeldt 0 siblings, 2 replies; 5+ messages in thread From: Stefan Israelsson Tampe @ 2021-09-28 9:55 UTC (permalink / raw) To: tomas; +Cc: guile-devel [-- Attachment #1: Type: text/plain, Size: 701 bytes --] Then this does not work well (fold min (inf) (list 1 2000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000 3 4)) which is a pity, we should have an exact inf as well On Tue, Sep 28, 2021 at 10:32 AM <tomas@tuxteam.de> wrote: > On Tue, Sep 28, 2021 at 10:15:30AM +0200, Stefan Israelsson Tampe wrote: > > Why is (min (inf) 1) = 1.0 inexact? > > Because inf's result is inexact. The same as (min 3 3.5) is inexact, > too. > > It seems that the `inexactness' is contagious across arithmetic > generics (I haven't found an explicit place in the Guile docs; > the racket docs are more explicit about that). > > Cheers > - t > [-- Attachment #2: Type: text/html, Size: 1080 bytes --] ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: (inf) min max 2021-09-28 9:55 ` Stefan Israelsson Tampe @ 2021-09-28 10:33 ` tomas 2021-09-28 12:00 ` Mikael Djurfeldt 1 sibling, 0 replies; 5+ messages in thread From: tomas @ 2021-09-28 10:33 UTC (permalink / raw) To: Stefan Israelsson Tampe; +Cc: guile-devel [-- Attachment #1: Type: text/plain, Size: 662 bytes --] On Tue, Sep 28, 2021 at 11:55:06AM +0200, Stefan Israelsson Tampe wrote: > Then this does not work well > > (fold min (inf) (list 1 > 2000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000 > 3 4)) > > which is a pity, we should have an exact inf as well Yeah, the idea of a numerical "tower" breaks down a bit in the presence of arbitrarily big ints and exact fractions of those. Suddenly, IEEE 754 aren't (always) at the tower's "top". It is as if someone attached a balcony to one of the tower's sides and put an even taller tower on top of that :-) Cheers - t [-- Attachment #2: Digital signature --] [-- Type: application/pgp-signature, Size: 198 bytes --] ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: (inf) min max 2021-09-28 9:55 ` Stefan Israelsson Tampe 2021-09-28 10:33 ` tomas @ 2021-09-28 12:00 ` Mikael Djurfeldt 1 sibling, 0 replies; 5+ messages in thread From: Mikael Djurfeldt @ 2021-09-28 12:00 UTC (permalink / raw) To: Stefan Israelsson Tampe; +Cc: guile-devel [-- Attachment #1: Type: text/plain, Size: 1132 bytes --] The proper way to handle this would, as you suggest, be to distinguish different kinds on infinities. Then, perhaps, countable infinity could be regarded as scheme:ish exact while infinities of higher cardinality would not (since scheme's handling of that kind of numbers is an approximation and, thus, not exact). Den tis 28 sep. 2021 11:56Stefan Israelsson Tampe <stefan.itampe@gmail.com> skrev: > Then this does not work well > > (fold min (inf) (list 1 > 2000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000 > 3 4)) > > which is a pity, we should have an exact inf as well > > On Tue, Sep 28, 2021 at 10:32 AM <tomas@tuxteam.de> wrote: > >> On Tue, Sep 28, 2021 at 10:15:30AM +0200, Stefan Israelsson Tampe wrote: >> > Why is (min (inf) 1) = 1.0 inexact? >> >> Because inf's result is inexact. The same as (min 3 3.5) is inexact, >> too. >> >> It seems that the `inexactness' is contagious across arithmetic >> generics (I haven't found an explicit place in the Guile docs; >> the racket docs are more explicit about that). >> >> Cheers >> - t >> > [-- Attachment #2: Type: text/html, Size: 1797 bytes --] ^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2021-09-28 12:00 UTC | newest] Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2021-09-28 8:15 (inf) min max Stefan Israelsson Tampe 2021-09-28 8:31 ` tomas 2021-09-28 9:55 ` Stefan Israelsson Tampe 2021-09-28 10:33 ` tomas 2021-09-28 12:00 ` Mikael Djurfeldt
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox; as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).