===============
Oct 17th, 2022
===============

.. Prep for the course
.. ~~~~~~~~~~~~~~~~~~~

Review
------

* ``array`` environment: align, hline, left & right
* ``theorem`` environment: named theorem
* ``bibliography``

Things to do
-------------

- ``includegraphics`` https://www.overleaf.com/learn/latex/Inserting_Images
- ``itemize`` environments; ``enumitem`` package https://ctan.org/pkg/enumitem?lang=en 

These notes are heavily based on the Overleaf page listed above. 

Images in LaTeX 
----------------

How to include images
~~~~~~~~~~~~~~~~~~~~~~

To include images in LaTeX, we need to prepare them in certain formats. 
Well-known formats such as PNG, JPEG, PDF are supported and work well. 
The package we need is ``graphicx``, and the command we use is ``\includegraphics[<options>]{filename}``. 
Assume that we have an image ``graph1.PNG``, the following code will include the image in the LaTeX output.

.. code-block:: latex
    :caption: include images

    % in preamble
    \usepackage{graphicx}

    % in body
    \includegraphics{graph1} % or
    \includegraphics{"graph1.PNG"} % or

You would notice that sometimes, the image size can be too big or small. 
If it is small and in PNG format, you'd need to find the original source. 
For big images, we can scale them down with options. Here are some examples. 

.. code-block:: latex
    :caption: image size

    \includegraphics[scale=0.5]{graph1} % half size 
    \includegraphics[width=5in]{graph1} % width 5 in 
    \includegraphics[width=\textwidth]{graph1} % match textwidth
    \includegraphics[width=0.5\textwidth]{graph1} % half of textwidth

How to position images
~~~~~~~~~~~~~~~~~~~~~~~

Without additional settings, these images are left-aligned, just like text blocks. 
Sometimes, we want to have more control about their positions. 
One way is to use the ``figure`` invironment. 
This is also useful when you need to refer to the image later, i.e., ``\ref{}`` to the images. 

.. code-block:: latex
    :caption: figure

    \begin{figure} 
    \includegraphics[width=0.5\textwidth]{graph1} % the half of the textwidth
    \centering        % I forgot to include this in class.
    \caption{Graph caption}
    \label{firstGraph}
    \end{figure}

The command ``\centering`` makes the image center aligned, and ``\caption{}`` creates a caption (it can be placed before ``\includegraphics`` to have top captions). 
Lastly, ``\label`` works the same way as in theorems, equations and etc; ``\label`` seems to require ``\caption{<name>}`` defined. 


More on positioning images
~~~~~~~~~~~~~~~~~~~~~~~~~~~

When including images, LaTeX decides where to place them. We may override this sometimes. The figure environment accepts position options. 

.. code-block:: latex
    :caption: figure

    \begin{figure}[t] % you may use, b,t,h and ! as well. They stand for ``bottom, top, here, and force``, respectively.
    \includegraphics[width=0.5\textwidth]{graph1} % the half of the textwidth
    \centering
    \end{figure}



Wrapfigure package
~~~~~~~~~~~~~~~~~~~~~~~~~~~

When you have a small figure and want to position it next to your text, try the ``wrapfigure`` package, https://www.overleaf.com/learn/latex/Wrapping_text_around_figures.

.. code-block:: latex
    :caption: wrapfig package

    %%%% in preamble
    \usepackage{wrapfig}

    %%%% in body
    \begin{wrapfigure}[lineheight]{position}{width}
    \includegraphics{graph1}
    \end{wrapfigure}


Image folder
~~~~~~~~~~~~~~~~

When there are several images, it is better to organize them as a folder. We do not need to include the prefix with the option ``\graphicspath{<relative path>}`` in your preamble. 


Enumitem package
-----------------

Today, we won't have enough time to cover the ``enumitem`` package. 
Instead, we use the ``shortlabels`` option so that ``enumitem`` works similarily to the ``enumerate`` package.

Recall to create an ordered list, we use ``\begin{enumerate}`` and ``\end{enumerate}``.

.. code-block:: latex
    :caption: enumerate

    %%%% body
    \begin{enumerate}
    \item a
    \item b
    \end{enumerate}

This will create an ordered list and the LaTeX class defines its label. 
There are many ways to customize the label (one can do this without using additional packages). 
A quick and convenient way to do this is to use the ``enumerate`` package or the ``enumitem`` package with the option ``shortlabels``. 


.. code-block:: latex
    :caption: enumerate/enumitem pacakge

    %%%% preamble
    \usepackage[shortlabels]{enumitem}  % With this enumitem works in a similar way as enumurate
    \usepackage{enumerate}              % This line is equivalent to the line above. 
                                        % Since the enumerate package is no longer actively managed 
                                        % we recommand the enumitem pacakge.

    %%%% body
    \begin{enumerate}[(A)]  % [<desired label>]
    \item a
    \item b
    \end{enumerate}

In the desired label, you may put many different labels such as ``a,A,i,I`` with or without parenthesis and with ``.``. 
Partial prerenthesis works too, e.g., ``\begin{enumerate}[i.)]`` creates labels ``i.)``, ``ii.)``, and so on.
That's all for this week.




.. class ends here