\section{Example of a MarkDoc
document}\label{example-of-a-markdoc-document}

\subsection{Standard Features}\label{standard-features}

\subsubsection{Some simple Stata input and
output}\label{some-simple-stata-input-and-output}

Here is a regression example using the obligatory \texttt{auto} dataset,
using good physics

\begin{verbatim}
      .  clear
      
      . sysuse auto
      (1978 Automobile Data)
      
      .  gen gp100m = 100/mpg
      
      . regress gp100m weight displacement gear_ratio foreign
      
            Source |       SS           df       MS      Number of obs   =        74
      -------------+----------------------------------   F(4, 69)        =     56.84
             Model |  91.7374232         4  22.9343558   Prob > F        =    0.0000
          Residual |  27.8388375        69  .403461414   R-squared       =    0.7672
      -------------+----------------------------------   Adj R-squared   =    0.7537
             Total |  119.576261        73  1.63803097   Root MSE        =    .63519
      
      ------------------------------------------------------------------------------
            gp100m |      Coef.   Std. Err.      t    P>|t|     [95% Conf. Interval]
      -------------+----------------------------------------------------------------
            weight |   .0014428    .000216     6.68   0.000     .0010118    .0018737
      displacement |   .0012388   .0021161     0.59   0.560    -.0029828    .0054603
        gear_ratio |  -.2037991   .3258603    -0.63   0.534    -.8538726    .4462744
           foreign |    .733736   .2301493     3.19   0.002     .2746007    1.192871
             _cons |   .8147969   1.239181     0.66   0.513    -1.657301    3.286895
      ------------------------------------------------------------------------------
      
      
      
\end{verbatim}

\subsubsection{Including a result in the body of a
sentence.}\label{including-a-result-in-the-body-of-a-sentence.}

This is useful for including results in sentences in a paper.

Markdoc can use inline expansion. As an example, we can see that the
coefficien t for the foreign variable is 0.734. It is, however, a
shortcoming that any par agraph including an inline result must all be
in a \texttt{txt} command in the Stata p ortion of the file.

Note that the next paragraph can be written as a standard paragraph.

\subsubsection{Including a graph}\label{including-a-graph}

Here is an example scatterplot command:

\begin{verbatim}
      .  twoway (scatter gp100m weight if !foreign) ///
         (scatter gp100m weight if foreign), ///
         legend(order(1 "US" 2 "Non-US"))
      
      
      
      
      
\end{verbatim}

Here is the graph.

\begin{figure}[htbp]
\centering
\includegraphics{./scatter.png}
\caption{An example scatterplot}
\end{figure}

\subsubsection{Hiding commands and showing only
results}\label{hiding-commands-and-showing-only-results}

It can be useful to hide commands and show just their output. Here, for
example, is the output from a summarize command:

\begin{verbatim}
          Variable |        Obs        Mean    Std. Dev.       Min        Max
      -------------+---------------------------------------------------------
            gp100m |         74     5.01928    1.279856   2.439024   8.333333
            weight |         74    3019.459    777.1936       1760       4840
      displacement |         74    197.2973    91.83722         79        425
        gear_ratio |         74    3.014865    .4562871       2.19       3.89
      
      
\end{verbatim}

Showing just commands works similarly.

Showing just commands or output is done line by line.

\subsubsection{Splitting input and
output.}\label{splitting-input-and-output.}

Markdoc cannot directly split input and output from Stata commands. This
is typical for programs producing documents directly from Stata log
files, because Stata itself mixes input and output in its log files. It
is possible to split output by running commands multiple time and
sometimes showing the comma nd, sometimes showing the output.

\subsection{Some other features to
check}\label{some-other-features-to-check}

\subsubsection{Showing Mata code and
output}\label{showing-mata-code-and-output}

Here is some Mata code. We don't want to see the output from the initial
mata co mmand, so we can hide it.

\begin{verbatim}
      .  mata
      ------------------------------------------------- mata (type end to exit) -------
      : X = (76, 53, 48 \ 53, 88, 46 \ 48, 46, 63)
      
      
      : Xi = invsym(X)
      
      
\end{verbatim}

It is useful to see the output from checking that Xi is really the
inverse of X.

\begin{verbatim}
      : Xi*X
                        1              2              3
          +----------------------------------------------+
        1 |             1   -1.11022e-16   -1.11022e-16  |
        2 |  -1.11022e-16              1              0  |
        3 |             0              0              1  |
          +----------------------------------------------+
      
      : end
      ---------------------------------------------------------------------------------
      
      . quietly log close example_md
      
\end{verbatim}
