Things

[jack]

Things I've done, not in any particular order.

* Got up at 8.30.
* Bought gel inner tube and more tyre patches.
* Bought extension cables (:p sonic). Albeit in the fourth shop on Newmarket road I went in.
* Reading Cryptonomicon again. It is still good. Is it one of the marks of a classic book that you keep noticing new things every time you reread it?
* Joined atreic and emporer and people in the Castle (their local! just beyond the post box, how cool?) for food and drink. There I:
* Had two binges
* Collected final word on my flowery shirt. I thought they were cheery (and incidently cheap) but everyone, friends and colleages, says 'no'. Though atreic said "no (but I like it)".
* I said many embarassing things some of which got written down ("Being short and froglike is more important than getting the girl").
* I am perceived as short person, despite not being really. This is interesting because I tend to do that, but wasn't sure how much other people did. I don't know if it's psychological, or if I just hunch, and either way if that's from deprecatingness or something else.
* There was mutual hand massaging. This is very relaxing.

Otherly, how come my last post got nearly 50 comments? I should haylp more often, assuming getting comments is the goal in life :)

Comments

[mair_in_grenderich]

binges of what?

[cartesiandaemon.livejournal.com]

Sorry. Last week Mobbsy linked to some research which defined a binge as 5 units, so whenever we have two pints we say oh my god, we're binging in a sarcastic voice.

[mair_in_grenderich]

ah, I'm behind the times. Or behind something, anyway.

(I got woken up. My mother decided at 2pm she could come and check her email.)

[cartesiandaemon.livejournal.com]

*checks* You don't know[1] Mobbsy so you wouldn't have seen that.

*hug* Were you insomniing last night?

I got woken up by me at 8.30. And then groaned a lot but was in by 9.30ish. Go me!

[1] Lit: have friended

[mair_in_grenderich]

I read friends-of-friends sometimes (when I get bored. not more than once an hour). (I've commented on at least one of Mobbsy's posts). otoh if would require me to be a friend-of, I certainly wouldn't have seen it.

I was making CDs burrrrrrrrrrrrrrrrrrrn until 7am.

CDs shiny! shiny CDs! in pink and yellow and blue!

Go you! *bounces sleepily*

[mair_in_grenderich]

otoh if would require me to be a friend-of, I certainly wouldn't have seen it.

oh, no, it wouldn't. I've just looked it up :-)

[mair_in_grenderich]

(but it was more than last week ago)

in other news, I need a mathmo. Why is the line of log(N!)/log(N) straight?

[cartesiandaemon.livejournal.com]

in other news, I need a mathmo.

Aha! Finally, I am teh irresistable! I knew maths would pay off.

Why is the line of log(N!)/log(N) straight?

Oh. Nevermind :) Is it? I can't remember exactly, but what happens when you substitute in Stirling's approximation (n! ~ sqrt(n).n^n.e^-n).

[mair_in_grenderich]

I looked at Stirling's approximation here:

http://mathworld.wolfram.com/StirlingsApproximation.html

and substituted it in,

and tried differentiating it,

and I can't see any reason why it would be straight. It just looked straight when I drew it.

http://flurble.org/plot.eps

[cartesiandaemon.livejournal.com]

Listen to Simon. The second post called it.

In fact, if you put a ruler against your graph you can see that the first inch *isn't* in line with the rest of it.

Using the approximation you see that the non-straight bit of the graph is about 1/log n, and differentiating gives 1/log n again, which between 20 and 90 gives a change in gradient of about 0.1.

[cartesiandaemon.livejournal.com]

Where did you come across this?

[mair_in_grenderich]

I made it up. All by myself.

[cartesiandaemon.livejournal.com]

Ooh. That's as cool -- in a different way -- to having come across it in the wild of some genuine computing problem :) Maths is fun, neh? :)

[mair_in_grenderich]

hm. well, maybe I came across it? I dunno. I was trying to work something out, and I worked out that it might be that. But actually I think it's possibly more than that.

I'll probably find I was completely wrong and the answer was 42.

maths are fun, but too hard for me.

[cartesiandaemon.livejournal.com]

"maths are fun, but too hard for me."

LOL at plural :)

"I'll probably find I was completely wrong and the answer was 42."

Yep. Or 1, or 0, or e. Coming across things is what maths is. And if someone else already knows it, you just know you have to keep trying 10E7 times and eventually you'll find a new one, get Simon to solve it, and be a mathematician and get a phd or a fields medal or something

[mair_in_grenderich]

I don't think it's 1, or 0, or e, I'm sure it's larger than 12, for sufficiently large N. Does that mean it must be 42?

[simont]

(Apologies for my first reply which I immediately deleted because it was drivel. I shouldn't try to do maths while my brain isn't working.)

It's only nearly straight. log(2!)/log(2) is 1; log(3!)/log(3) is 1.63093; and log(4!)/log(4) is 2.29248, whereas for a perfectly straight line it ought to be 2.26186.

As Jack observes, Stirling's formula gives the reason why. log(N!) is approximately equal to N log N - N + (log(2*pi*N))/2, and the first of those terms dominates the others; so log(N!)/log(N) is going to be roughly N plus some less important stuff. However, it would still be only an approximately straight line even if Stirling's approximation were exact.

[mair_in_grenderich]

is N log N straight? *sleepy*

[simont]

No, but N log N / log N is :-)

[mair_in_grenderich]

*wakes up*

oh yes.

[cartesiandaemon.livejournal.com]

That's what I thought you meant :)

[mair_in_grenderich]

what? me? what?

[cartesiandaemon.livejournal.com]

OK. I can never remember which of the people I know from different geek groups know each other and which don't.

"CDs shiny! shiny CDs! in pink and yellow and blue!"

OMG psycho mair *hugs* Get some sleep tonight. You an sing a C-D...

It's too easy to stay up that late, isn't it? OTOH it is nice to see the dawn and I barely ever do from the other end :)

[mobbsy.livejournal.com]

Ooh, people are talking about me er... *waves* *hides*

The only stuff I friends lock is work-related, and there isn't much of that.

[cartesiandaemon.livejournal.com]

*waves* Only about twice. You shouldn't be so interesting and helpful :) You know the experience of someone random appearing on your journal and saying "Well, it looked interesting..."? :)

"The only stuff I friends lock is work-related, and there isn't much of that."

Likewise. Well, I would if I ever posted anything about circumventing DVD region encryption or copyright, but I wouldn't :)