06:31 < [Coke]> iBakeCake: latest message on perl6-users about log(23,0) seems to be something in your current wheelhouse 06:32 < iBakeCake> [Coke]: what is it? 06:32 < iBakeCake> Isn't log base 0 undefined 06:32 < moritz> log to base 0? 06:32 < [Coke]> http://www.nntp.perl.org/group/perl.perl6.users/2016/10/msg3027.html 06:33 < moritz> m: say log(23, 0) 06:33 <+camelia> rakudo-moar 71a01e: OUTPUT«-0» 06:33 < moritz> that's the complaint 06:34 < iBakeCake> m: say log( my num $ = 23, my num $ = 0) 06:34 <+camelia> rakudo-moar 71a01e: OUTPUT«This type cannot unbox to a native number: P6opaque, Int in block <unit> at <tmp> line 1» 06:34 < iBakeCake> m: say log( my num $ = 23e0, my num $ = 0e0) 06:34 <+camelia> rakudo-moar 71a01e: OUTPUT«-0» 06:34 < iBakeCake> Well, I recently checked the log() stuff for nums... 06:34 * iBakeCake looks 06:34 < iBakeCake> Ah, ok, now I remember 06:35 < iBakeCake> m: say log(23)/−∞ 06:35 <+camelia> rakudo-moar 71a01e: OUTPUT«-0» 06:37 < iBakeCake> ln(0) by 2008 IEEE 754 is −∞; and log₀(23) = ln(23)/ln(0) = ln(23)/−∞ = -0 06:37 < iBakeCake> So it's not so much an artefact of the log() but rather how we divide by infinity 06:41 < iBakeCake> IEEE section 6.1 tells about division by −∞ would give the limit, with the sign of ∞, so -0 is right. and section 7.3 says that ln(0) is −∞ 06:41 < iBakeCake> If anyone wanted to respond to that person... I don't have a perl6-users subscriptions
On Thu, Oct 20, 2016 at 01:54:43PM +1100, Francis (Grizzly) Smit wrote: : I think I've found a bug some how there is no power that you can : raise 0 to and get 23 or any number, except 0 : : : $ perl6 -e "say log(23, 0);" : -0 : : : shouldn't it be NaN : : : $ perl6 --version : This is Rakudo version 2016.10-17-g200364a built on MoarVM version : 2016.10-15-g715e39a : implementing Perl 6.c. : : : -- : : .~. In my life God comes first.... : /V\ but Linux is pretty high after that :-D : /( )\ Francis (Grizzly) Smit : ^^-^^ http://www.smit.id.au/ : -----BEGIN GEEK CODE BLOCK----- : Version: 3.1 : GM/CS/H/P/S/IT/L d- s+:+ a++ C++++ UL++++$ P+++ L+++$ E--- W+++ : N w--- M-- V-- PE- PGP t+ 5-- X-- R- tv b++++ DI(+) D- : G e++ h+ y? r% z--- : ------END GEEK CODE BLOCK------ : http://www.geekcode.com/
