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[Witherweaver]

You use "log" because it's short for logarithm.  You don't need to specify a base, because there exists a standard base---base e.

Any different base should be specified.

[Witherweaver]

I mean using "ln" is okay, that's not the point.  The point is that ln = log.

Saying "log(x)" and meaning a base that is not e is misleading and should be avoided.

You're hardly ever going to need base 10 or base 2 or base pi, so in those cases just write log_10(x), log_2(x), log_pi(x).  Easy.

[Axxle]

That's stupid.  Log should always mean natural log. Other bases are only used for edge cases, and of course they're simply a multiple anyway.

[silverspawn]

I mean using "ln" is okay, that's not the point.  The point is that ln = log.

Saying "log(x)" and meaning a base that is not e is misleading and should be avoided.

You're hardly ever going to need base 10 or base 2 or base pi, so in those cases just write log_10(x), log_2(x), log_pi(x).  Easy.

but that's not true. you need ld. lots of sorting algorithms have ld(n) * n * c

[AndrewisFTTW]

Hey mathers, there's a thread about math called the maths thread. Here ya go:

http://forum.dominionstrategy.com/index.php?topic=11041.0

[sudgy]

Just to say what I was taught, I was taught that log by itself always means base 10, ln always means base e, and any other base needs to be specified.  (of course, you can say log_e)

[ashersky]

Are you all discussing All Your Base?  Or Ace of Base?  That's all I see when you guys talk.

[silverspawn]

i sit on this dirty floor
a weak mind for a cause
a cause i do not know
don't know what to live for
a compliment i've never heard
it's here even though...
it won't last for long

[sudgy]

I finally managed to beat the impossible quiz.  Without cheating.

[enfynet]

I successfully got all three gta5 characters over $1.5b using the assassination missions and stock market.

[KingZog3]

I successfully got all three gta5 characters over $1.5b using the assassination missions and stock market.

Now you can buy the tow truck company for $150 000 that pays you $150 for every car you deliver.

[qmech]

More on logs:

For mathematicians, writing ln (or worse, trying to pronounce it) is seen as a bit gauche, and tends to get beaten out of you quite early.

but that's not true. you need ld. lots of sorting algorithms have ld(n) * n * c

I saw ld for the very first time recently in a seminar and had to ask what it meant.  I can't have been the only one in that position, as someone else asked exactly the same question 5 minutes later.  Is it mostly a German thing?

[Tables]

In my experience from uni:

Mathematicians and (most) scientists use log to mean natural log
Engineers use log to mean base 10
Programmers and Computer Scientists use log to mean base 2

I don't know about other fields of study, but here in the UK you learn log is base 10 during A level and ln is base e (and most calculators are made the same way)

[Lekkit]

To me, log means either the kind Goko sometimes produce (and similar) or a chunk of wood. Depending on the context.

[Awaclus]

I've learned that you always have to specify log, and ln is used for natural log.

[pacovf]

I was taught that "ln" (pronounced "el en") was the natural logarithm, and "log" was base 10. I think that's because that's the way it is in Casio calculators.

More on logs:

For mathematicians, writing ln (or worse, trying to pronounce it) is seen as a bit gauche, and tends to get beaten out of you quite early.

I've seen loads of mathematician lecturers write "ln", more than "log" anyway. And do it badly at that ("di"? "10"? "ao"? Dafuq is this guy writing?")

[Kuildeous]

In my experience from uni:

Mathematicians and (most) scientists use log to mean natural log
Engineers use log to mean base 10
Programmers and Computer Scientists use log to mean base 2

I don't know about other fields of study, but here in the UK you learn log is base 10 during A level and ln is base e (and most calculators are made the same way)

So basically it sounds like log is a general designation for logarithm that has different default bases depending on the field you're in.

In order to teach the concept, schools start off with base 10, which is reasonable since many students don't even know about the existence of e yet. Once you get into a field that uses logarithms, then people bypass the more wordy "log in base x" and just use "log" with the understanding that your colleague knows that it's in base x. Good to know.

[Kirian]

unless you like to measure earthquake intensities, log means base e.

Base 10 is silly.  No one does that.

Chemist and engineer here.  Besides the Richter scale (on which 2 magnitudes = 1000-fold change):

pH uses common log.
Sound intensity and electrical signal intensity (dB) use common log.
Stellar magnitudes are based on common log (5 magnitudes = 100-fold change).
Neuroscientists express the Nernst equation in terms of the common log for intuition reasons.
Linkage analysis (genetics) expresses LOD scores using common log.
Slide rules (now obsolete, sure, but of historical importance) are based on the common log.

Logarithmic graphs are based on common log, because real-world phenomena that are graphed need to be read by real people who really use base 10 in real life.

Interestingly, the ISO specification is lg(x) for base 10 and ln(x) for base e.

Mathematician here.  When teaching calculus, and any math course, and anywhere throughout life

Conclusion:  Mathematicians are out of touch with how math is actually used throughout life.

And that's fine.

[Lekkit]

Drew1023 as long as I make a game move every 5 minutes it will give you lots of time to reflect on what a pathetic ***** you are
Drew1023 how about this you are a pathetic piece of trash that spends all day playing an online card game
Drew1023 that's pretty sad
Drew1023 yeah and I am free to remark on just how sad and pathetic it is and that you are wasting limited resources of the earth existing in your sad and pathetic little life
Drew1023 if all you are doing with your pathetic little life is staying in your mommy's basement and playing an online card game than you are not contributing and simply deserve to not live. You are very lucky I don't know where you liv or I'd do the world a favor.

So I play this guy. He's not saying anything. Then after he's been trying to piledrive the Estates for a couple of turns, I connect a King's Court with a Militia and is able to get a Province, he starts to act really funny. And then I realize. I know this guy from somewhere.

Lekkit: Hello.
Lekkit: Enjoy the game.
Lekkit: Sorry for being slow.
[I hit the Province buy]
Drew1023: yeah way to be a lucky little *****
Lekkit: Yup.
Lekkit: That's it.
Drew1023: why don't you just sit there for a few minutes and think about what a pathetic little *** you are
Lekkit: Sure thing. I'm at work, so I can do other stuff.
Drew1023: wow you really are ******* lazy aren't you
Drew1023: playing a game at work
Drew1023: pathetic trash like you is why the world is in the shape its in, parents probably never showed you what a good work ethic is
Drew1023: guess I can't really blame you for being the pathetic trash you are
Drew1023: you were just never taught better
Drew1023: here, have this game, its okay. I feel sorry for you now
Lekkit: Thank you very much, sir.
Drew1023 has left the game.

For some reason I get overly polite in a mocking manner whenever people start flaming me.

And if you're curious, here's the log for the game.

http://logs.prod.dominion.makingfun.com//20140721/log.512ba416e4b022198f05f8e2.1405948077088.txt

[AndrewisFTTW]

I have to apologize guys. When I'm angry at the world for whatever reason, I log into my Drew1023 account at work and yell at people for playing an online card game... that I am also playing. You see, I'm a lazy ***** who plays games at work. I guess I was just never taught better and my parents never showed me what a good work ethic is. I spend the rest of my life in mommy's basement playing this same online card game and I am truly not contributing anything to the world. But you can't blame me for being pathetic trash, I was just never taught better. I wish people would stop being so nice to me when I yell at them on the internet, it makes me feel sorry for them. I simply don't deserve to live but I'm very lucky I don't know where I live, or I'd do the world a favor.

[pacovf]

In order to teach the concept, schools start off with base 10, which is reasonable since many students don't even know about the existence of e yet.

My math teacher back in school defined ln as the function whose derivative is 1/x (and, arbitrarily, ln(1) = 0), so the first log I ever knew of was the one in base "e". He then showed that the inverse function of ln was equal to its derivative and defined exp(x) as that function. He only defined "log" in different basis afterwards.

Stories of my life^TM

[pingpongsam]

I pinched off a ln first thing this morning.

[SirPeebles]

Conclusion:  Mathematicians are out of touch with how math is actually used throughout life.

Oh please.  In any reasonable definition of "real life", logarithms aren't used at all.

[Witherweaver]

I mean using "ln" is okay, that's not the point.  The point is that ln = log.

Saying "log(x)" and meaning a base that is not e is misleading and should be avoided.

You're hardly ever going to need base 10 or base 2 or base pi, so in those cases just write log_10(x), log_2(x), log_pi(x).  Easy.

but that's not true. you need ld. lots of sorting algorithms have ld(n) * n * c

log_b(x) = log(x)/log(e), so difference is just multiplicative.

But that's not the point.  If log_b = ld, fine, and if log_e = ln, fine.  But e is the standard base and the usual way to define the log function.  So we omit the base, since base e is the way we define everything.  So log
=log_e.

[Witherweaver]

Conclusion:  Mathematicians are out of touch with how math is actually used throughout life.

Oh please.  In any reasonable definition of "real life", logarithms aren't used at all.

I use logs normally.  My life is real.