Discussion about math, puzzles, games and fun.   Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫  π  -¹ ² ³ °

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#1 2005-11-06 14:29:14

ryos
Member
Registered: 2005-08-04
Posts: 394

Can we use character entities?

I've wished for this a time or two. Let's see: > <  ⇒ Δ π Σ ≅ ∠∫ ≥ ≤

El que pega primero pega dos veces.

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#2 2005-11-06 14:31:20

ryos
Member
Registered: 2005-08-04
Posts: 394

Re: Can we use character entities?

Hmm...guess not. But, I think it would be much easier, or at least faster (for me, anyway) to use these than to copy and paste from the top.

Do we have [sup]sup[/sup] and [sub]sub[/sub] tags?

El que pega primero pega dos veces.

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#3 2005-11-06 14:32:38

ryos
Member
Registered: 2005-08-04
Posts: 394

Re: Can we use character entities?

Guess not. Also a good suggestion.

El que pega primero pega dos veces.

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#4 2005-11-06 16:54:44

MathsIsFun
Registered: 2005-01-21
Posts: 7,686

Re: Can we use character entities?

Good suggestions ... I will clear a bit of time and get my head stuck into the forum software and see what can be done.

"The physicists defer only to mathematicians, and the mathematicians defer only to God ..."  - Leon M. Lederman

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#5 2005-11-06 23:07:57

MathsIsFun
Registered: 2005-01-21
Posts: 7,686

Re: Can we use character entities?

After a bit of research, I think I can use "smiley" style for these special characters.

It would be something like typing Δ to produce Δ

(BTW We do have a functioning "math" tag that uses LaTeX code, but for a lot of things these characters work well.)

"The physicists defer only to mathematicians, and the mathematicians defer only to God ..."  - Leon M. Lederman

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#6 2005-11-07 18:16:26

ryos
Member
Registered: 2005-08-04
Posts: 394

Re: Can we use character entities?

Ah yes...LaTeX...that's on my to learn list.

Couldn't you just zap the & literalizer? What I mean is, when I type Δ, the forum software converts it to &Delta;.

Well, there must be some benefit to the & literalizer. Maybe you could just check for a ; within 10 chars or so to decide whither to literalize or not.

El que pega primero pega dos veces.

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#7 2005-11-07 18:47:25

MathsIsFun
Registered: 2005-01-21
Posts: 7,686

Re: Can we use character entities?

That is an idea, but I prefer to allow/disallow stuff specifically so that hackers can't take advantage.

I can't think how replacing :blah with &blah could be used for hacking, but that could be because I'm not a hacker.

At the moment I have about 60 symbols I want to apply this "smiley" thing to, and I have done some timing, and it can do the find/replace in under a millisecond. I think a millisecond overhead per post is OK.

"The physicists defer only to mathematicians, and the mathematicians defer only to God ..."  - Leon M. Lederman

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#8 2005-11-07 20:07:24

MathsIsFun
Registered: 2005-01-21
Posts: 7,686

Re: Can we use character entities?

OK, here we are, I have made the changes. Hopefully I haven't made anyhing else go crazy, but I am sure someone will let me know!

To make any of these work, put a ":" in front of the text.

alpha=α and=∧ ang=∠ asymp=≈ beta=β bull=• cap=∩ cong= cup=∪ deg=° Delta=Δ delta=δ divide=÷ empty=∅ epsilon=ε equiv= exist=∃ fnof=ƒ forall=∀ frac12=½ frac14=¼ frac34=¾ gamma=γ ge=≥ harr= hArr= infin=∞ int=∫ isin=∈ lambda=λ laquo=« larr= lArr= le=≤ mu=μ nabla=∇ ne=≠ ni=∋ notin=∉ nsub=⊄ omega=ω oplus=⊕ otimes=⊗ part=∂ Phi=Φ pi=π plusmn=± prime=′ Prime=″ prod=∏ prop=∝ radic=√ raquo=» rarr= rArr= rho=ρ Sigma=Σ sigma=σ sim=∼ sube=⊆ sub=⊂ sum=∑ sup1=¹ sup2=² sup3=³ supe=⊇ sup=⊃ tau=τ there4=∴ theta=θ times=× xi=ξ zeta=ζ

I also did a trick with some of them, for example "pi" looks a lot more like pi really does (π vs π) because I used a different font for it.

Thanks ryos for the great idea.

Example usage:
π 22 ÷ 7

``:pi :cong 22 :divide 7``

"The physicists defer only to mathematicians, and the mathematicians defer only to God ..."  - Leon M. Lederman

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#9 2005-11-07 20:21:00

justlookingforthemoment
Moderator
Registered: 2005-05-26
Posts: 2,161

⊂ ° ° ζ !

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#10 2005-11-07 20:25:40

MathsIsFun
Registered: 2005-01-21
Posts: 7,686

Re: Can we use character entities?

Still laughing ... !!!

"The physicists defer only to mathematicians, and the mathematicians defer only to God ..."  - Leon M. Lederman

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#11 2005-11-08 08:38:23

mathsyperson
Moderator
Registered: 2005-06-22
Posts: 4,900

Re: Can we use character entities?

What does mean? Or is it supposed to be something other than a box?

π ≈ 22/7 works for me, although 355/133 is a much better estimate.

Anyway, it's a very useful addition. It's much better than just copying and pasting from the top, and we have more symbols to choose from too.

Why did the vector cross the road?
It wanted to be normal.

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#12 2005-11-08 14:04:44

ryos
Member
Registered: 2005-08-04
Posts: 394

Re: Can we use character entities?

Awesome, that was really quick!

∀ ∠ ∃ θ

El que pega primero pega dos veces.

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#13 2005-11-08 14:06:36

ryos
Member
Registered: 2005-08-04
Posts: 394

Re: Can we use character entities?

Do we need to separate them with spaces?

ΔγΦ

El que pega primero pega dos veces.

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