Template talk:Log 2

ln, ld, lb, lg, and any other l?

Hi, I think there are in practice three popular bases:

1. e for ln (log. naturalis, also known as log hyp, same idea as the h in sinh etc., so maybe lh could make sense, or rather, do not use lh for anything that is not the same as ln).
2. 10, now mostly historic, but I still learned it in school. AFAIK these beasts are known as Brigg's logarithms, but nobody would say lb when they mean log10 or simply log, because 10 used to be some kind of default. Nevertheless I'm not confident that lb for binary is a good idea, because this abbreviation could be also confused with pounds (derived from libre or similar).
3. 2, relevant for everything remotely related to CS or bits. A possible name is log2, an established name is ld (logarithmus dualis). I've never seen {{lg}} or {{lb}} before for this purpose. –Frank Ellermann 13:39, 19 September 2011 (UTC)

I've never seen ld in my life. I very frequently see lg for the base-2 logarithm, and occasionally (rarely) lb. I've never heard or seen any reference to the natural log as "log hyp". Charles R Greathouse IV 14:30, 19 September 2011 (UTC)

Using DDG as recommended on SeqFan "log hyp" confirmed my vague recollection that log hyp was the name used by Gauss. The ld thingy could be an idiosyncrasy of German CS (Informatik) about three decades ago. "ld" followed by a click on "science + math." annotates: The logarithm of base 2, \mathrm{ld}(x)=\log_2(x), from the Latin logarithmus dualis.

(some minutes later)

MathWorld confirms "German oddity" for ld, but also says that lg is a bad idea. Well, in rxshell I picked base 2 as default for log, and use ln for log hyp. IIRC I used ld in some sequences — for the reasons noted above lb /lg/log are ambiguous when you can't enforce a definition. –Frank Ellermann 15:05, 19 September 2011 (UTC)

See also Template talk:Log 10#Redirect. On MathWorld's Common Logarithm and especially Lg, I see the conflicting meanings that you mention. It seems that it might be better to delete the {{lb}} and {{lg}} redirects then (should I just delete them?,) and just keep {{ln}} for natural logarithm, since there is consensus on that one! — Daniel Forgues 16:57, 19 September 2011 (UTC)

If you think that {{lb}} and {{lg}} help, e.g., apparently you and Charles would intuitively know what they do, and I'd intuitively avoid them, then these redirects are fine as is. I was only surprised by the idea of using some lx for what I know as ld when I looked into the recent changes, but that's now clear, thanks. –Frank Ellermann 20:59, 19 September 2011 (UTC)

I will avoid using them too, since their meaning is ambiguous. It was not a good idea after all to create those ambiguous redirects. — Daniel Forgues 23:54, 19 September 2011 (UTC)

I'm not sure of the use-case of the templates in the first place. I wouldn't mind if {{lg}} and {{lb}} went nowhere. Charles R Greathouse IV 03:23, 20 September 2011 (UTC)

I removed any reference to {{lg}} and {{lb}} and flagged {{lg}} and {{lb}} as discarded. Since those two abbreviations have ambiguous meaning, I should have avoided them in the first place. — Daniel Forgues 05:09, 20 September 2011 (UTC)