# Mathematical Equations on EP

EP has a new feature! The ability to format mathematical equations via mimeTeX and primitive graphing from WZgrapher. LaTeX is commonly used by mathematicians as well as economists to format complex mathematical equations in Academic papers. Of course using HTML codes or good old fashioned export to image from Excel or even Matlab still works great on EP!

To figure out the syntax to display complex mathematical equations, you can start with the above links, the graph link is slightly more clear.

Then, this wikipedia on math markup gives some more short cuts on how to format mathematical formulas using LaTeX syntax. (Note, the syntax for the formulas should (pretty much) be LaTeX, this is a faster version for server CPU load reduction). Then, this howto on LaTeX has some basic mathematical symbols.

You wrap your LaTex syntax in  special tags.

Here is an example:

syntax:

$$\frac{\partial^2 y}{\partial x_1\,\partial x_2}$$

produces the partial derivative symbol:
$\frac{\partial^2 y}{\partial x_1\,\partial x_2}$

This was all prompted by Bayes Theorem, a keystone of conditional probability. (LaTeX syntax here.

syntax:

$$\Pr(A|B)=\frac{\Pr(B|A)\Pr(A)}{\Pr(B|A)\Pr(A)+\Pr(B|\neg A)\Pr(\neg A)}$$

produces:

$\Pr(A|B)=\frac{\Pr(B|A)\Pr(A)}{\Pr(B|A)\Pr(A)+\Pr(B|\neg A)\Pr(\neg A)}$

## Forum Categories:

### Hate to be a real

geek but I gotta check this out!

Let's try some Greek letters

$$\rho = \Sigma^{N}_{i=1} |i \rangle \langle i|[\tex] or maybe something more format challenging [tex]\int^{\infty}_{-\infty} \frac{\Gamma d \omega}{(\omega + i \Gamma)(\omega - i \Gamma)}[\tex] Didn't work :( You must have Javascript enabled to use this form. ### hate to debug This is my generic check it works for admin in comments [tex]\frac{\partial^3 z}{\partial^2 x_1\,\partial^2 x_2}$$

So, firstly copy the above and paste in your comment and make sure it's not a browser/OS/user permission set issue.

$\frac{\partial^3 z}{\partial^2 x_1\,\partial^2 x_2}$

Next. It won't work when there are syntax errors. So to check to make sure the actual script is working try using an mimeTeX syntax known to be correct.

I don't recognize your exact equation (because my knowledge of LaTex is "hunt n peck", and yes I should know it better but ....I don't, so now I have an additional reason to figure it out in order to try to discuss some of these Academic economics papers I scan quite a bit...but I digress...

I think it's this:

$$\rho=\Sigma_{i=1}^n |i\rangle \langle i|$$

which produces this:

$\rho=\Sigma_{i=1}^n |i\rangle \langle i|$

Then on the next one, I really am unsure what it is, but I caught one syntax error with the integral indices, note you flipped the _ with the ^ in yours.

$$\int_{\infty}^{-\infty}$$

$\int_{\infty}^{-\infty}$

ah, wait a second, no space (?) after integral?

So corrected:

$$\int_{\infty}^{-\infty}\frac{\Gamma d \omega} {(\omega + i \Gamma)(\omega - i \Gamma)}$$

$\int_{\infty}^{-\infty}\frac{\Gamma d \omega}{(\omega + i \Gamma)(\omega - i \Gamma)}$

This is painful, believe me if I do this, it better be a damn good equation to put on a blog. ;)

I decided to add it because there have been times I wanted to add equations and run a graph on data/equation but it seems we do have some math heads and people who might actually use this stuff...saw enough requests decided it was worth it. But assuredly "an exercise for the advanced EP user!" I hope you use it.

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### Very slick!

It seems MimeTex is a little fussier than LaTex (which is fussier than raw TeX), just enough to catch the inattentive user. But they did a nice job just getting more than just the most basic of symbols to work.

BTW, you got the equations right, except for reversing the limits on the integration. I'd be a little surprised if those are used in economics -- they're from chemical physics (not all of us are formally trained in economics, after all). The first is the quantum mechanical density operator in matrix form; the second is just the integral over a Lorentzian (factoring the denominator makes the poles really obvious). If you have to write a LOT of equations, everything else is much more painful.

Thanks for doing this. I'll have to play with graphing next -- but I'll read the instructions first for that.

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### this should be fun

You can integrate in reverse, from -inf to inf, so I thought that's how you wanted it.

That's very, very cool you have that level of math geek....

Then, you can parse actual formula for CDOs, which I looked at and said WTF, because the assumptions were not valid, from a mathematical view.

I've seen a lot of advanced mathematics used in some of the Academia economic tourism I've engaged in.

Very very cool but we can also just put the more advanced GDP equations, productivity equations etc. in posts...

but I have assumed no one would know what we were talking about and those who would...hopefully would be polite if we made a mistake! So, in other words, at least for myself to translate all mathematics into English in posts...

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