bachelor_thesis/thesis/chapters/appendix.tex

% vim: ft=tex
\section{Appendix}

\subsection{Source Code for the Benchmarks}
\label{ref:code_benchmarks}

The benchmarks used in \ref{ref:performance} are done using this code. Note
that the execution time is measured which is inherently noisy. To account for
the noise several strategies are used:

\begin{enumerate}[1]
    \item{The same circuit is applied to the starting state several times. The
        minimal result is used as the noise must be positive}
    \item{Several circuits are applied to the starting state. The remaining
        noise is mixed with the variance due to the different circuits.}
    \item{Because the noise can be timely correlated (i.e. another process
        requires processor time for a longer period) the tests have been
        randomized such that the time correlated noise is distributed randomly over
        several uncorrelated measurements.}
\end{enumerate}

The code used to benchmark the three regimes is analogous and not included here.

\lstinputlisting[title={Generating Data for the Dense State Vector vs. Graphical Simulator Benchmark}, language=Python, breaklines=true]{../performance/generate_data_scaling_qbits.py}

\lstinputlisting[title={Code for Measuring and Computing the Execution Time and Statistics}, language=Python, breaklines=true]{../performance/measure_circuit.py}

\subsection{Complete Graphical States from the Three Regimes}
\label{ref:complete_graphs}

Because the whole graphs are barely percetible windows have been used
in Figure \ref{fig:graph_high_linear_regime} and Figure \ref{fig:graph_intermediate_regime}.
For the sake of completeness the whole graphs are included here in Figure \ref{fig:graph_low_linear_regime_full},
Figure \ref{fig:graph_intermediate_regime_full} and Figure \ref{fig:graph_high_linear_regime_full}.

\begin{figure}[H]
    \centering
    \includegraphics[width=\linewidth]{graphics/graph_low_linear_regime.png}
    \caption[Typical Graphical State in the Low-Linear Regime]{Typical Graphical State in the Low-Linear Regime}
    \label{fig:graph_low_linear_regime_full}
\end{figure}

\begin{figure}[H]
    \centering
    \includegraphics[width=\linewidth]{graphics/graph_intermediate_regime.png}
    \caption[Typical Graphical State in the Intermediate Regime]{Typical Graphical State in the Intermediate Regime}
    \label{fig:graph_intermediate_regime_full}
\end{figure}

\begin{figure}[H]
    \centering
    \includegraphics[width=\linewidth]{graphics/graph_high_linear_regime.png}
    \caption[Typical Graphical State in the High-Linear Regime]{Typical Graphical State in the High-Linear Regime}
    \label{fig:graph_high_linear_regime_full}
\end{figure}

\subsection{Code to Generate the Example Graphs}
\label{ref:code_example_graphs}

This code has been used to generate the example graphs used in
\ref{ref:performance}. Note that generating the graph is done using a random
circuit as used in \ref{ref:code_benchmarks}. The generated \lstinline{dot}
code is converted to an image using 
\lstinline{dot i_regime.dot -Tpng -o i_regime.png}.

\lstinputlisting[title={Code used to Generate the Example Graphs}, language=Python, breaklines=true]{../performance/regimes/graph_intermediate_regime.py}


\subsection{Code to Benchmark \lstinline{ufunc} Gates against Python}
\label{ref:benchmark_ufunc_py}

It has been mentioned several times that the implementation using
\lstinline{ufuncs} as gates is faster than using a \lstinline{python}
implementation.  To support this statement a simple benchmark can be used. The
relatively simple Pauli $X$ is used, more complicated gates like $CX$ or $H$
have worse performance when implemented in \lstinline{python}. The performance
improvement when using the \lstinline{ufunc} is a factor around $6.4$ in this tested
case. One must however note that the tested \lstinline{python} code is not
realistic and in a possible applications there would be a significant overhead.

\lstinputlisting[title={Code to Benchmark \lstinline{ufunc} Gates against Python}, language=Python, breaklines=True]{extra_benchmark/benchmark.py}

When using \lstinline{result_py[0::2] = qm_state[1::2]} the result is identical and
the performance is only increased by a factor around $1.7$. This method is however not
applicable to general act-qbits and the bit mask has to be used.