# Help:TeX

Formulas in AWF-Wiki are created with the Tex markup language. Everyone who used LaTeX before is familiar with this. For those users that do not have any experiences with TeX it might be hard work for the first formula! Nevertheless it is defenetly worth the trouble, because the outcome is perfect. If you once formated formulas in TeX, you can also import them in many other applications.

Unfortunately it is defenetly not possible to write down a formula without any knowledge about TeX. The following example shows a medium complex estimator for the variance of a stratified sample:

\[\hat {var} (\bar y) = \sum_{h=1}^L \left\lbrace \left( \frac {N_h}{N} \right)^2 \hat {var} (\bar y_h) \right\rbrace = \frac{1}{N^2} \sum_{h=1}^L N^2_h \frac {N_h-n_h}{N_h} \frac {S^2_h}{n_h}\]

This formula is the outcome of the following syntax:

**:<math>\hat {var} (\bar y) = \sum_{h=1}^L \left\lbrace \left( \frac {N_h}{N} \right)^2 \hat {var} (\bar y_h) \right\rbrace = \frac{1}{N^2} \sum_{h=1}^L N^2_h \frac {N_h-n_h}{N_h} \frac {S^2_h}{n_h}</math>**

The above estimator is not complicate, we can imagine much more complex expressions in (Forest)science and you can imagine that it takes time to get familiar with this kind of markup. In case that you want to contribute to AWF-Wiki but you are afraid of this, let us know and we can help! We are a strong community of scientists and there are always some experienced people who can help!

We created a template for this purpose, so if you are not able to express you formular you can enter **{{formulahelp}}** at the position the formula should appear. If you have any other possibility to present your formula (perhaps you can export it as a image out of your application) enter it here, so that people know what to do!

You can find a very complete Dokumentation about TeX in the Wikipedia Metawiki (Shift + click opens this page as a new window). We abdicate from copying this content into AWF-Wiki, it is more efficient to use this source. If you open this link in a seperate window you can learn and copy from the examples presented.

If you use a formel editor that is able to export TeX markup you are lucky and able to just copy and paste your formulas in between the **<math> </math>** tags!