day2latex.tex

\documentclass[a4paper,10pt]{report} % {article}
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  \usepackage{amsthm}
   

% --- graphic and formating ------------------
  % bibliography
  \usepackage[sort,comma]{natbib} 
  % settings
  \usepackage{enumitem}
  \usepackage{setspace}
  \usepackage{pdflscape}
  \usepackage{graphicx}
  \usepackage{wrapfig}
  \usepackage[hypcap]{caption}
  \usepackage{subcaption}
  % \usepackage[cm]{fullpage}
  \usepackage[top=2cm, bottom=1.7cm, left=3.6cm, right=1.1cm]{geometry}
  % \usepackage[leftmargin=2.5cm]{geometry}
  %\usepackage{subfigure}
  %\usepackage{caption}
  %\usepackage{subcaption}  
  \usepackage{placeins}
  \usepackage{makeidx}      % uncomment when making index
  \usepackage{epstopdf}
  % \usepackage{tocloft}     % custom lists
  % \usepackage{minitoc}     % table of content in a chapter
  
   \usepackage{listings}     % code listings
  % \usepackage[printwatermark]{xwatermark} % \usepackage{draftwatermark}
  
  \usepackage[colorlinks=true,linkcolor=interlink,citecolor=DarkCite]{hyperref}
  
  % \usepackage{picture}
  \usepackage[usenames,dvipsnames]{xcolor}
  \usepackage{colortbl} 
  

   \setlength{\headsep}{16pt} 
%     
   \usepackage{fancyhdr} 
 % ---- fancy page setting -------------- 
   %\input{./latex/style_header_footer.tex}
   \input{./latex/style1headerfooter.tex}
  %-----------------------------
  
  % picture libraries
  \usepackage{tikz} % Required for flow chart
   \usetikzlibrary{arrows,positioning} % Tikz libraries required for the flow chart in the template
   
       \tikzset{
        %Define standard arrow tip
        >=stealth',
        %Define style for boxes
        point/.style={
           rectangle,
           rounded corners,
           draw=black, very thick,
           text width=6.5em,
           minimum height=2em,
           text centered},
        % Define arrow style
        pil/.style={
           ->,
           thick,
           shorten <=2pt,
           shorten >=2pt,}
    }

   \usepackage{csvsimple}  % csv table
   
   \usepackage{lipsum}    % filler text
   
   
  \hypersetup{
    % bookmarks=false,         % show bookmarks bar?https://www.overleaf.com/project/637266f5927ea984e19f515e
    % unicode=false,          % non-Latin characters in Acrobat’s bookmarks
    % pdftoolbar=false,        % show Acrobat’s toolbar?
    % pdfmenubar=false,        % show Acrobat’s menu?
%     % pdffitwindow=false,     % window fit to page when opened
    % pdfstartview={FitH},    % fits the width of the page to the window
    pdfinfo={
        Title={Informal LaTeX workshop},
        Author={InScAPE group},
        Creator={Your Name Here},
        Producer={Institute for Geophysics and Meteorology},
        Subject={Informal LaTeX workshop on intermediate and advanced topics},
        Keywords={tables, tikz, counters} 
    },
    %pdfauthor={Author},     % author
    %pdfsubject={Subject},   % subject of the document
    %pdfcreator={Creator},   % creator of the document
    %pdfproducer={Producer}, % producer of the document
    %pdfkeywords={keyword1, key2, key3}, % list of keywords
    % pdfnewwindow=true,      % links in new PDF window
    colorlinks=true,       % false: boxed links; true: colored links
    linkcolor= darkred,          % color of internal links (change box color with linkbordercolor)
    linkbordercolor = red, %
    urlbordercolor = {0 0.6 1},   % 
    citecolor=green,        % color of links to bibliography
    filecolor=cyan,         % color of file links
    urlcolor=magenta       % color of external links
    % pdfborderstyle={/S/U/W 1}% border style will be underline of width 1pt
} 

% ---- new commands --------------------------
  % ----- link colours ------------
    \newcommand{\reffig}[1]%
    {\hypersetup{linkcolor=figlink}%
    \ref{#1}%
    \hypersetup{linkcolor=interlink}}
 
  % ---- math symbols  ----------------------- 
  \newcommand{\e}{\mathrm{e}}  
  \newcommand{\dx}{\mathrm{d}}
  \newcommand{\normal}{\mathbi{n}}
  \newcommand{\bsigma}{\mathbf{t}}
  \newcommand{\vnull}{\mathbf{0} \!\!\! ^{ _{ _{\scriptscriptstyle -}}}}
  \newcommand{\vnullt}{\mathbf{0}^{ \mathrm{T} \!\!\!\!\!\!\! \! _{ _{\scriptscriptstyle -}}}}
  % ---- math fonts -------------------------- 
  \newcommand{\mathbs}[1]{\textsf{#1}}
  \newcommand{\mathbi}[1]{\textbf{\emph #1}}
  \newcommand{\mathff}{\textbf{\textit f}}
  \newcommand{\mathbis}[1]{\textsf{\em #1}}
  \newcommand{\mathcb}[1]{\boldsymbol{\mathcal #1}}
  \newcommand{\thv}{\theta_{\scriptscriptstyle \mathcal{V} }}
  \newcommand{\thml}{
      \theta^{\scriptscriptstyle \mathrm{(ML)}}
  }
  \newcommand{\sayabout}[3][mean]{
      The #2 known under name #3 is very #1
  }
  % --- modifying existing commands -------------------
  \renewcommand{\contentsname}{\small{Overview of Pieces}}
  
  % --- graphic commands --------------------
  \DeclareGraphicsExtensions{.png,.jpg} 

  % --- colour definition ------------------
  % colour definition
  \definecolor{GreenDone}{rgb}{0.2,0.7,0.2} 
  \definecolor{darkred}{rgb}{0.6,0,0}
  \definecolor{darorange}{rgb}{0.6,0.2,0}
  % --- counters -----
  \newcounter{samplecode}[chapter] 

% \pdfinfo{  % this gets overwrittten by hyperref
%   /Title    (Advance LaTeX Workshop) 
%   /Author   (Your Name Here)
%   /Creator  (Your Name Here)
%   /Producer (InScAPE)
%   /Subject  (Intermediate and Advanced LaTeX)
%   /Keywords (listing, tikz, macrtos)
% }
\title{Advanced LaTeX Workshop}
\author{Your Name Here} 
\date{19 June 2023} 
%--------------
\makeindex      % uncomment when making index page
\begin{document}
% setting counters
 \thispagestyle{plain} 
 \pagenumbering{roman}  
 \setcounter{page}{1}
%-------- Workshop overview-------------------------------
 \section*{Preface} 
 
 This document is a second part of the guidebook on intermediate and advanced topics in \LaTeX, with a target audience of researchers and other professionals who often have to use \LaTeX.
 The first part of the guidebook in the file \texttt{day1latex.tex} covers topics such as automatically generated lists, setting up counters, modifying figures, as well as customizing links.
 The most up-to-date version is maintained on GitHub: \href{https://github.com/jchylik/advanced_latex_workshop}{github.com/jchylik/advanced\_latex\_workshop}. \ \\\\
 
 
 This guidebook was originally started for the purpose of a informal workshop held at the University of Cologne. 
% The original overview follows:
%
% \noindent
% You can work from CIP workstation or bring your own device.~\\
%
% \begin{tabular}{l p{0.7\textwidth}}
%   target audience: & people with previous experience with \LaTeX \\
%   aims:  & discuss \LaTeX ~topics practice skills \\
%   duration: & one and half hour from start time or until you start getting tired \\
%   topics: & see following chapters \ref{chap:intro}, \ref{chap:monday}, and \ref{chap:wednesday} \\
%   registration: & comment in this Slack thread \\ 
% \end{tabular}

%--------------
\maketitle
 
\chapter{Intro} \label{chap:intro}

%\pagenumbering{arabic} 
\setcounter{page}{3} 

Shall we begin?

\section{Combining Document from Pieces}
Combining documents from multiple files speeds up the editing process, makes collaboration easier, and also lowers the risk of accidentally rewriting something. You can see an example how most of the header of this document is in a separate file.
% #1 
To try this, write some dummy text in a separate file and insert is here using the \texttt{input} command:\\
% \input{filename}

% #2 
The \texttt{input} statement can also work on multiple levels
\begin{enumerate}
    \item Make a copy of \texttt{style1headerfooter.tex} and modify it.
    \item Open \texttt{in1header.tex} and replace \texttt{style1headerfooter.tex} with the name of your new file.
    \item Recompile the main document.
\end{enumerate}



\subsection{Automatically Generated Lists}\label{sec:automatic}
There is an easy way how to create list of figures, tables, as well as index of phrases. 

% We are going to start witth this documet
%  #1 change the class of document from article to report
%  


  % \let\clearpage\relax 
  \tableofcontents 
   \label{contents}
   \addcontentsline{toc}{section}{Table of Contents} %\let\clearpage\relax
   \listoftables  
   \addcontentsline{toc}{section}{List of Tables}
     %\let\clearpage\relax 
   \listoffigures
   \addcontentsline{toc}{section}{List of Figures}
   \newpage 
   \lstlistoflistings
   \addcontentsline{toc}{section}{Listings}  
   \label{listings}  
   \chapter*{List of Symbols}
   \addcontentsline{toc}{section}{List of Symbols}
   \input{./latex/list_symbols.tex}
\newpage

\chapter{Monday} \label{chap:monday}
 \pagenumbering{arabic}
 \pagestyle{fancy}
 
 The topics covered on Monday are in a separate document \href{./day1latex.pdf}{day1latex.pdf}

 \newpage 
 
  
\chapter{Wednesday} \label{chap:wednesday}

 

We will start with:
\input{./data/sillytext1.txt}  
%\input{./data/sillytext2.txt}

\section{Guidelines}
To speed up today the progress of the workshop today, the new commands are not only listed in the text but also included as comments. To make the commands actives, just remove or add comment signs.

\section{External tools}
First we will have a quick look at the \emph{latexdiff} tool from the last time.
But this time, we will  show its shortomings. First, look at the beginning of today chapter and swap which lines are commented between  \texttt{sillytext1.txt} and \texttt{sillytext2.txt}\\

Secondly, open your shell, change to the folder with this file and type \stepcounter{samplecode} (example \alph{samplecode}): 

\begin{lstlisting}[language={bash}
   ,frame=single                           % simple frame 
   ,showstringspaces=false                  % how to display strings
   ,basicstyle=\footnotesize\color{cyan}    % setting font
   ,keywordstyle=\color{magenta}            % setting font for keywords 
   ,stringstyle=\color{brown}
   ,commentstyle=\color{ForestGreen} 
]
  latexdiff day2latex.tex day2latex_v2.tex > different.tex
\end{lstlisting}~\vspace{1ex}
\stepcounter{samplecode}

and then compile the output file. Does it highlight any differences?\\

Fortunately, there is a way to show the differences in the included files. Use the option \texttt{--flatten} which merges all the \texttt{input} files before comparing \stepcounter{samplecode} (example \alph{samplecode}):
\begin{lstlisting}[language={bash}
   ,frame=single                           % simple frame 
   ,showstringspaces=false                  % how to display strings
   ,basicstyle=\footnotesize\color{cyan}    % setting font
   ,keywordstyle=\color{magenta}            % setting font for keywords 
   ,stringstyle=\color{brown}
   ,commentstyle=\color{ForestGreen} 
]
  latexdiff --flatten  day2latex.tex day2latex_v2.tex > differentshow.tex
\end{lstlisting}~\vspace{1ex}

We can also play with the style of the latexdiff file. \\


And with the option \texttt{--type}, we can also define how the changes appear. The two most useful choices are:
\begin{itemize}
 \item UNDERLINE --- the added text is not only blue, but also underlined 
 \item PDFCOMMENT --- changes are not marked in the text, but as PDF comments! 
\end{itemize}

Go ahead and give it a try \stepcounter{samplecode} (example \alph{samplecode}):

\begin{lstlisting}[language={bash}
   ,frame=single                           % simple frame 
   ,showstringspaces=false                  % how to display strings
   ,basicstyle=\footnotesize\color{cyan}    % setting font
   ,keywordstyle=\color{magenta}            % setting font for keywords 
   ,stringstyle=\color{brown}
   ,commentstyle=\color{ForestGreen} 
]
  latexdiff --flatten --type=PDFCOMMENT day2latex.tex day2latex_v2.tex > differentcom.tex
\end{lstlisting}~\vspace{0ex}

\subsection{Other tools}

There are a couple of other tools that can speed up your work with .
Unfortunately they are not installed here. But you can try them later:
\begin{itemize}
    \item \emph{pdfgrep} --- similar to grep, searches inside a PDF document that was already compiled; See: \href{https://www.geeksforgeeks.org/pdfgrep-command-in-linux/}{tutorial},  \href{https://pdfgrep.org/doc.html}{man page}
    \item \emph{pdftk} --- tool for splitting, combing and mixing pdf documents; See: \href{https://www.pdflabs.com/docs/pdftk-cli-examples/}{pdft examples}
\end{itemize}
%-> add links 


\section{Fillers}
 \subsection{Filler Text}
 Sometimes we need to test whether the structure of the document and the formatting works. Instead of spending time copying and pasting random stuff, we use the \index{filler!lore ipsum} \emph{Lore Ipsum} generator.
In the header we already inserted \texttt{lipsum} package, and here we insert the following command \stepcounter{samplecode}(example \alph{samplecode}):
\begin{lstlisting}[language={[latex]tex}, frame=single,basicstyle=\footnotesize]
  \lipsum[0-2]    %generates dummy text
\end{lstlisting}
 \subsubsection{Example of Filler Text}
\lipsum[0-1]    % lore ipsum 


\section{Code Listing with Highligths}
You have already seen example of code listing in the previous paragraphs. Now we will look at this topic in more detail.
With the package \textbf{listings}, you can show the structured code and highlight parts of it. The location of the code could be:
\begin{itemize}
 \item Directly copy and paste to the \LaTeX  document --- see listing \ref{code:python}.
 \item You point to the source code file 
 \begin{itemize}
  \item[\(\circ\)] You just need to state the path to the file and which lines to list
  \item[\(\circ\)] You can event point to the source code of this very file (see \ref{code:thislatex}).
 \end{itemize}
\end{itemize}

\setcounter{lstlisting}{\value{samplecode}}
\refstepcounter{samplecode}
\begin{lstlisting}[language={python}       % listing: python code
   ,caption={Copy and paste a few lines of python code (example \alph{samplecode})}
   ,label={code:python} 
   ,frame=single, captionpos=b              % simple frame and caption below
   ,showstringspaces=false                  % how to display strings
   ,basicstyle=\footnotesize\color{cyan}    % setting font
   ,keywordstyle=\color{magenta}            % setting font for keywords 
   ,stringstyle=\color{brown}
   ,commentstyle=\color{ForestGreen} 
  ]
 langs = ["Python","Bash","Matlab","R"]     # strings brown, comments in dark green
 pick = random.randint(0, len(langs))       # pick random index
 print("Do you sometimes use {} to generate {} files?".format(langs[pick],"LaTeX")) 
\end{lstlisting}                            % end of one listing

\refstepcounter{samplecode} 
\lstinputlisting[ language={[latex]tex}     % new listing: tex syntax, latex option
  ,caption={Self-showing code (example \Alph{samplecode}) with highlighted \index{code!highlight} syntax and line numbers}
  ,label={code:thislatex}
  ,firstline=357                            % where in the file to start
  ,firstnumber=357                          % adjusting the shown numbers
  ,lastline=385                             % what is the last line
  ,numbers=left
  ,captionpos=b, breaklines=true
  ,frame=single
  ,basicstyle=\scriptsize\color{darkgray}   % setting smaller font
  ,keywordstyle=\bf\color{magenta}
  ,commentstyle=\color{ForestGreen}         % comments in different colour
]{./day2latex.tex}                          % this exact file
% {./latex/day2latex_backup.tex}   % alternative code location

\noindent You can try it yourself:
\begin{enumerate}
 \item Change colour which highlights keywords. \index{code!highlight}
 \item Change the comments fonts to italics (hint: \texttt{\textbackslash it})
 \item Adjust the path to the code so it is listing part of this file that your are working on.
\end{enumerate}

\subsection{Callback to Monday}
\begin{enumerate} 
 \item Make the symbol after the word ``example'' in \ref{code:thislatex} is consistent with the rest of examples. 
 \item Instead of the \emph{listing} counter is starts with the value of the \emph{example} counter, make it that the \emph{example} counter being (re)set to the value of the \emph{listing} counter.
 \item Recompile and look how it appears on the page \pageref{listings}
\end{enumerate}

\subsection*{Further Reading}
\addcontentsline{toc}{subsection}{Further Reading}
\begin{itemize}
 \item \href{https://www.overleaf.com/learn/latex/Code_listing}{Overleaf Guidelines on code listings.}
 \item \href{https://nasa.github.io/nasa-latex-docs/html/examples/listing.html}{NASA code listing examples}
 \item \href{https://texdoc.org/serve/listings.pdf/0}{Documentation of Listing Package}
\end{itemize}


\newpage 

\section{Tables}

Sometimes we directly write a table \index{table} in the \LaTeX document. But sometimes we need values from and external file. Shall we just copy and paste them?~\vspace{2ex}\\
Sure, if you want to risk messing up the whole document and losing the newest values.~\vspace{2ex}

\noindent
A better solution is to export the table in a separate file and just input here, such as:
\refstepcounter{samplecode} 
\begin{lstlisting}[language={[latex]tex}, frame=single,basicstyle=\footnotesize, breaklines=true, basicstyle=\scriptsize\color{darkgray}, frame=single,
  keywordstyle=\bf\color{magenta}, commentstyle=\color{ForestGreen} ]
  \input{/somefolder/exported_table.tex}
\end{lstlisting}

\noindent
This might seem like a good choice solution at first, but it still means that we need to export the table to \LaTeX format every time we change some value in the source data. Would it be perhaps possible do read the values directly from the source file? A short answer is yes: there are even some more comfortable solutions.

\subsection{Importing Tables} \label{sec:tables}
Instead of copy \& paste values into tables, we just import \index{table!import} them \emph{from an external} \index{csv} \emph{csv file} and format them. Although the following code might seem complicated at first, it is pretty straightforward and it saves us a lot of time. The command \texttt{\textbackslash csvreader} is followed first by the basic definition of the alignment of the column, then the source file \index{table!import!csv}, which columns from the source we output, and finally displaying the columns:\\




\refstepcounter{samplecode} 
\lstinputlisting[ language={[latex]tex},      % tex syntax, latex option
  caption={Importing from csv file (example \alph{samplecode})}, label={code:csvimport}, 
  firstline=443, firstnumber=443, lastline=454, numbers=left, captionpos=b,
  breaklines=true, basicstyle=\scriptsize\color{darkgray}, frame=single,
  keywordstyle=\bf\color{magenta}, ,commentstyle=\color{ForestGreen}  % comments in different colour
]{./day2latex.tex}   % 


\begin{table}[h!] \label{tab:import}
  \begin{center} 
  \csvreader[
      tabular = |r|r|r|,               
  ]{./data/values.csv}                 % table location
  {  z=\zvec, u=\uvec, theta=\thvec    % mapping of columns
  }{%
     \zvec  & \uvec & \thvec           % which columns to show
  } % 
  \caption[short table description]{This is a table imported from the csv file. }
  \end{center}
\end{table} ~\vspace{1ex}

This approach ahas a number of advantages:
\begin{itemize}
 \item It saves time, we do not need to rewrite any values.
 \item No need to open the whole data file, the command just points to the part that is used.
 \item If the data file changes, we do not need to adjust our \LaTeX document, we just compile it again.
 \item The styling of the table is separate from the data in the table.~\vspace{2ex}
\end{itemize}


You might have noticed that our table is missing a header \index{table!header}. We can easily add it into the first optional argument of the command.\\


\refstepcounter{samplecode} 
\lstinputlisting[ language={[latex]tex},      % tex syntax, latex option
  caption={Importing from csv file (example \alph{samplecode})}, label={code:csvimport_header}, 
  firstline=440, firstnumber=470, lastline=460, numbers=left, captionpos=b,
  breaklines=true, basicstyle=\scriptsize\color{darkgray}, frame=single,
  keywordstyle=\bf\color{magenta}, ,commentstyle=\color{ForestGreen}  % comments in different colour
]{./latex/day2latex_backup.tex}   %

\begin{table}[h!] \label{tab:import_better}
  \begin{center} 
  \csvreader[
      tabular = |r|r|r|, 
      table head  = \hline 
          \( \quad  z \; \lbrack \mathrm{m} \rbrack  \) 
          &  \(  \; \bar{u} \;  \lbrack \mathrm{m\, s}^{-1} \rbrack \)
          & \(  \quad \quad \Big. \bar{ \theta }  \; \lbrack \mathrm{K} \rbrack \Big. \) 
          \\
          \hline ,
      table foot = \hline 
          & \multicolumn{2}{ c|}{\( \ldots \) } 
          \\ \hline
  ]{./data/values.csv}                 % table location
  {  z=\zvec, u=\uvec, theta=\thvec    % mapping of columns
  }{%
     \zvec  & \uvec & \thvec           % which columns to show
  } % 
  \caption[short table description]{This is a table imported from the csv file. Apart from that this caption is way to long to be shown in the list of tables. And we will also further style-up the table. }
  \end{center}
\end{table} ~\vspace{1ex}



\subsection{Modifying Number Formats}

% \newpage 
\subsection{Table Styling}

  We can easily add additional cells to the table.
  
  \begin{table}[h!] \label{tab:styled}
  \begin{center}
  \csvreader[
      tabular = |r|r|r|, 
      table head  =
          %\hline 
          \multicolumn{1}{ c }{ ~}
          & \multicolumn{2}{|c|}{ measured } \\
          \hline 
          \( \quad  z \; \lbrack \mathrm{m} \rbrack  \) 
          &  \(  \; \bar{u} \;  \lbrack \mathrm{m\, s}^{-1} \rbrack \)
          & \(  \quad \quad \Big. \bar{ \theta }  \; \lbrack \mathrm{K} \rbrack \Big. \) 
          \\
          \hline  ,
      table foot = \hline \hline    % doubled horizontal line
         \multicolumn{1}{|c|}{\( \ldots \) }
          & \multicolumn{2}{ c|}{\( \ldots \) } 
          \\ \hline
  ]{./data/values.csv}  % table location
  {  z=\zvec, u=\uvec, theta=\thvec    % mapping of columns
  }{%
     \zvec  & \uvec & \thvec        % which columns to show
  } % 
  \caption[short table description]{This is a table imported from the csv file. Apart from that this caption is way to long to be shown in the list of tables. And we will also further style-up the table. }
  \end{center}
\end{table} ~\vspace{1ex}
  
  What else would you like to modify in the table?

\newpage
\section{Macros}
We can very much speedup work in \LaTeX with \index{macro} macros --- simple scripts and aliases that speed-up the work.

If we repeatedly write a complicate math expression or symbol, such as
\[ \theta^{\scriptscriptstyle \mathrm{(ML)}} =  \]
we can define \index{macro!definition} it as a macro (in the preamble of the documents)

\stepcounter{samplecode}(example \alph{samplecode}):
\begin{lstlisting}[language={[latex]tex},
    frame=single,basicstyle=\footnotesize,showstringspaces=false, 
     keywordstyle=\color{magenta}, stringstyle=\color{brown}, commentstyle=\color{ForestGreen}
    ]
  \newcommand{\thml}{                            % macro name 
      \theta^{\scriptscriptstyle \mathrm{(ML)}}  % inner code
  }                                              % close brackets
\end{lstlisting}
and then just output \( \thml \) by calling the macro:
\begin{lstlisting}[language={[latex]tex},
    frame=single,basicstyle=\footnotesize]
     \thml
\end{lstlisting}
\index{macro!definition@{\bf{definition}}}
Try to define a macro for your favourite colour math symbol and use it! \\

\subsection{Macro Arguments}
\index{macro!argument}
Macros can also take a number of arguments, here for example 3, with the first two being optional and predefined. You can see in the preamble of this documents:

\refstepcounter{samplecode} 
\lstinputlisting[ language={[latex]tex},      % tex syntax, latex option
  caption={Macro with arguments (example \alph{samplecode})}, label={code:macroarg}, 
  firstline=141, firstnumber=141, lastline=143, numbers=left, captionpos=b,
  breaklines=true, basicstyle=\scriptsize\color{darkgray}, frame=single,
  keywordstyle=\bf\color{magenta}, commentstyle=\color{olive}  % comments in different colour
]{./latex/day2latex_backup.tex}   

And then you call it:
\begin{lstlisting}[language={[latex]tex},
    frame=single,basicstyle=\footnotesize]
     \sayabout[rude]{person}{Jan}
\end{lstlisting}
which outputs: \sayabout[rude]{person}{Jan}.\\

\noindent
Let us play with this macro: \index{macro!argument!optional}
\begin{enumerate}
 \item Call it without the optional argument from the call. 
 \item Call it with changed arguments. 
\end{enumerate}

\subsection{Redefing Macros}
Not only we can define new macros, but we can \emph{carefully} redefine \index{macro!definition!redefine}them using the \texttt{\textbackslash renewcommand}.\\

\begin{enumerate}
 \item Look at the title at the page \pageref{contents}
 \item Search in the preamble for \texttt{\textbackslash renewcommand} and change it to something meaningful.
 \item Try to redefine some other macro. 
\end{enumerate}


\subsection{More on Macros} 
 We can also write \index{macro!conditions} conditional macros which allows us to say IF something, THEN do something, ELSE do something else. For that we would use package \texttt{ifthen} and call it:
 

\begin{lstlisting}[language={[latex]tex},
    frame=single,basicstyle=\footnotesize,showstringspaces=false, 
     keywordstyle=\color{magenta}, stringstyle=\color{brown}, commentstyle=\color{ForestGreen}]
    \ifthenelse{\equal{\thing}{\string whatever}}
    {% True case
      \newcommand{\result}{thing is `whatever'.}%
    }
    {% false case
      \newcommand{\result}{thing is something else.}%
    }
 \end{lstlisting}
 
 We can even use \texttt{foreach} command from the package \texttt{tikz}. This is particularly useful for drawing repeated patterns.
 
\section{Index Page}
Index \index{index} is a very popular part of books and longer documents.
To generate it, we need to use the package \texttt{makeidx} in the preamble and the command 
\begin{lstlisting}[language={[latex]tex},
    frame=single,basicstyle=\footnotesize]
     \makeindex
\end{lstlisting}
also in the preamble.\\

In the body of the document we then place commands \texttt{\textbackslash index} next to relevant occurrences of keywords.\\

For example:
\refstepcounter{samplecode} 
\lstinputlisting[ language={[latex]tex},      % tex syntax, latex option
  caption={Macro with arguments (example \alph{samplecode})}, label={code:index}, 
  firstline=429, firstnumber=429, lastline=430, numbers=left, captionpos=b,
  breaklines=true, basicstyle=\scriptsize\color{darkgray}, frame=single,
  keywordstyle=\bf\color{magenta}, commentstyle=\color{olive}  % comments in different colour
]{./latex/day2latex_backup.tex}  % {./day2latex.tex} %{./latex/day2latex_backup.tex}   


When we want to index a specific combination of words, but group them together on the index page, we separate them by exclamation marks:

\begin{lstlisting}[language={[latex]tex},
    frame=single,basicstyle=\footnotesize,showstringspaces=false, 
     keywordstyle=\color{magenta}, stringstyle=\color{brown}, commentstyle=\color{ForestGreen}]
   \index{macro!argument} 
   \index{macro!argument!optional} 
 \end{lstlisting}

You can see the result on the following page:


% ---  index--------------
  \clearpage
  \phantomsection                       % to keep good formatting 
  \addcontentsline{toc}{subsection}{Index Page Itself} 
  \label{index}  
  \printindex   
%-------------------------
   
  \subsection{Tasks for the Index}
  \begin{enumerate}
   \item Looks up examples of index entries in this document.
   \item Add some with sub-entries. 
   \item Modify the style of some of them.
  \end{enumerate}

  
\section{Formatting} 
\subsection{Dashes}
Dash is not the same thing as minus. 
Lets see the difference between following symbols:\\
- \\
-- \\
--- \\
 
 \section{Posters and Slideshows} 
 If you have been struggling with Powerpoint, there is a way out \( \ldots \) 
 

 




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