# Itex programming

1. Apr 7, 2007

### sylas

I don't see any forum where I can just test out itex programming, so I'm doing it here. I will try to delete this thread after posting. My apologies if I can't do that.

BD = $(2\omega + 3)/(2\omega + 4)$ 0.0409

In paper: 2/3(3/2 - 2ξ/η), and fs 1 - σ/η

Using itex
$\sigma = \frac{1}{\sqrt{(2\varpi+3)(2\varpi+4)}}$

Added in edit... sorry. I could not delete. It is annoying that the preview facility seems not to preview itex. I think?

Oh well. Now that the thread is here, I'll see how resizeing works, both outside itex and inside.

First, putting the above inside size tags.
$\sigma = \frac{1}{\sqrt{(2\varpi+3)(2\varpi+4)}}$

Second, adding a "large" tag inside the itex. (Not the proper way to do it in real LaTeX.)
$\large \sigma = \frac{1}{\sqrt{(2\varpi+3)(2\varpi+4)}}$

Hm. Can I make a formula larger some other way?

Last edited: Apr 7, 2007
2. Apr 7, 2007

### MeJennifer

Last edited: Apr 7, 2007
3. Apr 7, 2007

### mattmns

Instead of using itex use tex:

$$\sigma = \frac{1}{\sqrt{(2\varpi+3)(2\varpi+4)}}$$

4. Apr 7, 2007

### sylas

OK... let me try...

$$\sigma = \frac{1}{\sqrt{(2\varpi+3)(2\varpi+4)}}$$
$$\eta = \sqrt{\frac{2\varpi+4}{2\varpi+3}}$$
$$\xi = 1 - \eta + 2\varpi$$
geodetic factor $$\frac{2}{3}(\frac{3}{2} - 2\frac{\xi}{\eta}) = 1 - \frac{4\xi}{3\eta}$$

$$\begin{array}{rcl}\frac{2}{3}(\frac{3}{2}-\frac{2\xi}{\eta}) &=&1-\frac{4\xi}{3\eta}\\ &=&1-\frac{4-4\eta+8\sigma}{3\eta}\\ &=&1-\frac{4}{3}\sqrt{\frac{2\varpi+3}{2\varpi+4}}+\frac{4}{3}-\frac{8}{3}\sqrt{\frac{(2\varpi+3)}{(2\varpi+4)^2(2\varpi+3)}}\\ &\approx&1-\frac{4}{3}(1-\frac{1}{2(2\varpi+4)})+\frac{4}{3}-\frac{8}{3(2\varpi+4)}\\ &=&1+\frac{1}{3(\varpi+2)}-\frac{4}{3(\varpi+2)}\\ &=&1-\frac{1}{\varpi+2}\end{array}$$

Excellent -- just what I want. But what is the difference? tex still seems to use a math mode. Where are these documented?

Using the various preview tools at other sites is helpful, but I don't feel confident that the implementation will be exactly as it is here.

Cheers -- Sylas

Last edited: Apr 8, 2007
5. Apr 8, 2007

### mattmns

The difference is that itex is small, and tex is big Generally, you use itex when you are writing math in-line. And you use tex whenever you feel like you need/want to. For example, as you saw, fractions sometimes are difficult to read when you use itex, so it is probably better to use tex for fractions.

Consider the following example.

I am using itex here: $\sum_{i=1}^{\infty}x^i$ and I am using tex here: $$\sum_{i=1}^{\infty}x^i$$. See how tex is kind of messing with the line spacing.

Last edited: Apr 8, 2007
6. Apr 8, 2007

### sylas

Aha. That link was great. It would be good to have as a standard help page.

TeX has both inline and displaymath styles; and the two tags tex and itex handle those two cases.

Trying an equation...

$$\begin{equation*}\begin{split}\frac{2}{3}(\frac{3}{2}-\frac{2\xi}{\eta})&=1-\frac{4\xi}{3\eta}\\&=1-\frac{4-4\eta+8\sigma}{3\eta}\\ &=1-\frac{4}{3}\sqrt{\frac{2\varpi+3}{2\varpi+4}}+\delta\end{split}\end{equation*}$$

Last edited: Apr 8, 2007