115 lines
4.3 KiB
TeX
115 lines
4.3 KiB
TeX
\documentclass{beamer}
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\usepackage{graphicx}
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\usepackage{multicol}
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\usepackage{hyperref}
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\usepackage{lipsum} % for placeholder text
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\graphicspath{{pdf_images/}}
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\title{ECON 4530/5530 \\ Computational Economics}
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\subtitle{Data transformation}
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\author{Alex Gebben}
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\begin{document}
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% Title Slide
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\begin{frame}
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\titlepage
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\end{frame}
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%%%%%%%%%%%%%%%%%%
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\begin{frame}{Commenting Code}
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\only<1-3>{
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\onslide<1-3>{Comments are lines of code which do not run. These are \textbf{\emph{very}} important. }
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\newline
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\onslide<2-3>{ In R these are created by starting a line with ``\#''}
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\onslide<3>{
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\begin{enumerate}
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\item{You should add a comment to any line of code which is not highly simple.}
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\item{Keep a clean comment style}
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\item{Comment above a section of code. Indent the following code}
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\item{Always include the why of your code. The what and how of your code is less critical}
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\item{Think about what you would need to know if you forgot everything about the project}
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\end{enumerate}
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}
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}
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\only<4>{
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\includegraphics[width=0.7\textwidth]{What_Comments}
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\includegraphics[width=\textwidth]{Why_Comments}
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}
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\end{frame}
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\begin{frame}{Section Comments}
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Section comments visually separate chunks of code. It is an excellent practice to distinguish types of analysis, or groups of code.
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\newline
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\vspace{1em}
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\onslide<2->{\includegraphics[width=\textwidth]{Section_comments.png}}
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\newline
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\vspace{1em}
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\onslide<3->{RStudio provides a keyboard shortcut to create these headers \texttt{(Cmd/Ctrl + Shift + R)}}
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\end{frame}
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%%%%%%%%%%%%
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\begin{frame}{\emph{if} statements}
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\only<1-8>{
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\emph{If} only run code when certain condtions are met
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\newline
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\onslide<2->{ \textbf{Possible uses}}
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\begin{enumerate}
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\onslide<3->{\item Load a file only if it does not exist }
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\onslide<4->{\item Switch the value of an entry}
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\onslide<5->{\item Create a new dummy variable}
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\onslide<6->{\item Account for changes in column names on servers}
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\end{enumerate}
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\onslide<7->{Can be combined with \emph{else}}
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\newline
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\onslide<8->{The R function \texttt{ifelse()} can be a good shortcut}
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}
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\only<9>{\includegraphics[width=0.75\textwidth]{If.png}}
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\end{frame}
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%%%%%%%%%%%%%%%%
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\begin{frame}{Class Exercise}
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Use an if statement to write a csv file in a ``Data'' directory if the folder exists, otherwise it creates the directory first.
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\end{frame}
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%%%%%%%%%%%%
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\begin{frame}{functions}
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\only<1-6>{
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\emph{functions} save a set of code to use later.
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\newline
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\onslide<2->{They are exactly the same as the functions you already use in R}
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\onslide<3->{Must define function inputs, code and output}
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\begin{enumerate}
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\onslide<4->{\item Use if you repeat code more than twice }
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\onslide<4->{\item Stores complex code avoids typos}
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\onslide<5->{\item Can be loaded in script files}
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\onslide<6->{\item Could be used in your own library}
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\end{enumerate}
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}
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\only<7>{\includegraphics[width=\textwidth]{Function.png}}
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\only<8>{The \texttt{try()} function can be useful when creating your own functions. It prevents the code from stopping after a failure. Use with care.}
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\end{frame}
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%%%%%%%%%%%%%%%%
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\begin{frame}{Class Exercise}
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Turn the previous if statement into a function. Allow the user to pass in the name of the folder that is created.
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\end{frame}
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%%%%%%%%%%%%%%%%%%%
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\begin{frame}{Class Exercise}
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\only<1>{\LARGE Remember proper naming of files, data and scripts. Provide clear comments.}
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\only<2>{
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\begin{enumerate}
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\item Identify three data set you are interested in on FRED
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\item Load one data set using a URL saved as a character variable
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\item Create a raw data subdirectory and save the raw data into it
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\item Clean the data, at least update the column names
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\item Save the cleaned data as a CSV and an RDS file in a cleaned data subdirectory with proper names
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\item Include a comment on the first line of the file explain what the code is used for and why.
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\item Comment any other code as needed
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\item Turn this code into a function where the user passes in the URL, and column names
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\item Save function in a separate Rscript in a directory for scripts. Pay attention to the name
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\item In the main directory create a Rscript and in that script load script
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\item Use the function to clean all three data sets
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\item After this add a section of code to find the mean, and summary of the data
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\end{enumerate}
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}
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\end{frame}
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\end{document}
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