# Contribution instructions

Here you have some guidelines regarding your contribution, using markdown. If you’re not yet familiar with this typesetting, have a look at this cheat sheet. Moreover, have a look at this markdown file in a proper text editor (say Vim).

## (British) English

This website uses English spelling. So, there will be *colours*, *labelling*, *analogue*, *behaviour*, *modelled*, *maximum*, and so on.

## Adding figures

When adding figures, make sure they are centred in the page. To do this, follow this syntax:

```
<center>
<img src="{{site.baseurl}}/images/week01/01-3/Network.png" style="zoom: 40%; background-color:#DCDCDC;" /><br>
<b>Figure 2:</b> Network architecture.
</center>
```

In this particular example, the author chose to resize the image to 40% of its original size. Given that the image had a transparent background, an additional light colour (`#DCDCDC`

) has been added to the background.
Note that you *must* use prepend the file with `{{site.baseurl}}`

. Otherwise, it will not work on GitHub pages.

## Adding figures side by side

In this case the author displayed two figures, side by side, using a table.

```
| <center><img src="{{site.baseurl}}/images/week01/01-3/Spiral1.png" width="200px"/></center> | <center><img src="{{site.baseurl}}/images/week01/01-3/Spiral2.png" height="170px"/></center> |
| (a) Input points, pre-network | (b) Output points, post-network |
<center><b>Figure 1:</b> Five color spiral.</center>
```

Moreover, since a specific size was needed, `width`

or `height`

can be specified.

## Adding headings

When adding headings, using two or three `#`

, add an extra empty line in the source code.

```
Some text from a preceding paragraph.
- - 1 - -
- - 2 - -
## New heading
- - 1 - -
More text.
```

## Adding mathematical formula

This website uses *KaTeX*, therefore you may want to check out what the supported $\TeX$ functions are. For inserting some in-line formula, enclose it in single dollar signs, for example `$y = mx + q \in \mathbb{R}$`

renders as $ y = mx + q \in \mathbb{R}$. To insert a centred formula, you want to follow this syntax (pay attention to the empty lines).

```
Some text.
- - 1 - -
$$
ax^2 + bx + c = 0 \quad\Rightarrow\quad
_1x_2 = {-b \pm \sqrt{b^2 - 4ac} \over 2a}
$$
- - 1 - -
Some more text.
```

Some text.

\[ax^2 + bx + c = 0 \quad\Rightarrow\quad _1x_2 = {-b \pm \sqrt{b^2 - 4ac} \over 2a}\]Some more text.

## Mathematical notation

I am writing here a non exhaustive list of mathematical notation we’re going to use for the class website. We are planning on adding macros to ease writing.

- The transposition symbol is
`$^\top$`

, which looks like $^\top$. - Vectors should use a lower-case bold and italic typesetting. This can be done with
`$\boldsymbol{x}$`

and looks like $\boldsymbol{x}$. We may want to add a macro`\vect{}`

for this. - Matrices should use a upper-case bold and italic typesetting. This can be done with
`$\boldsymbol{A}$`

and looks like $\boldsymbol{A}$. We may want to add a macro`\matr{}`

for this. - Function names are
**not**in italic, hence`$\max(\cdot)$`

,`$\log(\cdot)$`

,`$\tanh(\cdot)$`

, which look like $\max(\cdot)$, $\log(\cdot)$, $\tanh(\cdot)$, and so on. - The
*exponential*function is`$\exp(\cdot)$`

, $\exp(\cdot)$, and not`$e^{(\cdot)}$`

, $e^{(\cdot)}$. - Computer names use
`$\texttt{}$`

in the mathematical environment. For example we can write`$\texttt{ReLU}(\cdot)$`

for $\texttt{ReLU}(\cdot)$. If we are just talking about computer stuff, then we shall write`ReLU`

or`torch.relu()`

. While writing formulas we should prefer using`$(\cdot)^+$`

, $(\cdot)^+$, for the positive part.