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mj-msc.tex
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@ -226,16 +226,17 @@ straightforward to adjust for different scales.
Both algorithms are part of PostGIS, a free-software GIS suite:
\begin{itemize}
\item {\DP} via
\href{https://postgis.net/docs/ST_Simplify.html}{PostGIS \texttt{ST\_Simplify}}.
\href{https://postgis.net/docs/ST_Simplify.html}{PostGIS \textsc{st\_simplify}}.
\item {\VW} via
\href{https://postgis.net/docs/ST_SimplifyVW.html}{PostGIS \texttt{SimplifyVW}}.
\href{https://postgis.net/docs/ST_SimplifyVW.html}{PostGIS
\textsc{st\_simplifyvw}}.
\end{itemize}
It may be worthwhile to post-process those through a widely available Chaikin's
line smoothing algorithm\cite{chaikin1974algorithm} via
\href{https://postgis.net/docs/ST_ChaikinSmoothing.html}{PostGIS
\texttt{ST\_ChaikinSmoothing}}.
\textsc{st\_chaikinsmoothing}}.
To use in generalization examples, we will use two rivers: Šalčia and Visinčia.
These rivers were chosen, because they have both large and small bends, and
@ -277,12 +278,12 @@ simplification for scale 1:\numprint{50000} and especially for
\centering
\begin{subfigure}[b]{.49\textwidth}
\includegraphics[width=\textwidth]{salvis-douglas-64-50k}
\caption{Using {\DP}}
\caption{Using {\DP}.}
\end{subfigure}
\hfill
\begin{subfigure}[b]{.49\textwidth}
\includegraphics[width=\textwidth]{salvis-visvalingam-64-50k}
\caption{Using {\VW}}
\caption{Using {\VW}.}
\end{subfigure}
\caption{Generalized using classical algorithms (1:\numprint{50000}).}
\label{fig:salvis-generalized-50k}
@ -299,12 +300,12 @@ figure~\onpage{fig:salvis-generalized-chaikin-50k}.
\centering
\begin{subfigure}[b]{.49\textwidth}
\includegraphics[width=\textwidth]{salvis-douglas-64-chaikin-50k}
\caption{{\DP} + Chaikin's}
\caption{{\DP} + Chaikin's.}
\end{subfigure}
\hfill
\begin{subfigure}[b]{.49\textwidth}
\includegraphics[width=\textwidth]{salvis-visvalingam-64-chaikin-50k}
\caption{{\VW} + Chaikin's}
\caption{{\VW} + Chaikin's.}
\end{subfigure}
\caption{Generalized and smoothened river (1:\numprint{50000}).}
\label{fig:salvis-generalized-chaikin-50k}
@ -314,12 +315,12 @@ figure~\onpage{fig:salvis-generalized-chaikin-50k}.
\centering
\begin{subfigure}[b]{.49\textwidth}
\includegraphics[width=\textwidth]{salvis-overlaid-douglas-64-chaikin-50k}
\caption{{\DP} + Chaikin's}
\caption{{\DP} + Chaikin's.}
\end{subfigure}
\hfill
\begin{subfigure}[b]{.49\textwidth}
\includegraphics[width=\textwidth]{salvis-overlaid-visvalingam-64-chaikin-50k}
\caption{{\VW} + Chaikin's}
\caption{{\VW} + Chaikin's.}
\end{subfigure}
\caption{Zoomed-in generalized and smoothened river + original.}
\label{fig:salvis-overlaid-generalized-chaikin-50k}
@ -549,7 +550,7 @@ We will explain two instances on when automated tests were very useful during
the implementation:
\begin{itemize}
\item Created a function \texttt{wm\_exaggeration}, which exaggerates bends
\item Created a function \textsc{wm\_exaggeration}, which exaggerates bends
following the rules. It worked well over simple geometries, but, due to
a subtle bug, created a self-crossing bend in Visinčia. We copied the
offending bend to the automated test suite and fixed the bug. The test
@ -632,7 +633,7 @@ easier than discriminating different line shapes or colors.
\subsection{Debugging}
NOTE: this will explain how intermediate debugging tables (\texttt{wm\_debug})
NOTE: this will explain how intermediate debugging tables (\textsc{wm\_debug})
work. This is not related to the algorithm, but the only the implementation
itself (probably should come together with paper's regeneration and unit
tests).
@ -641,7 +642,7 @@ tests).
NOTE: explain how different river segments are merged into a single line. This
is not explained in the {\WM} paper, but is a necessary prerequisite. This is
implemented in \texttt{aggregate-rivers.sql}.
implemented in \textsc{aggregate-rivers.sql}.
\subsection{Bend scaling and dimensions}
\label{sec:bend-scaling-and-dimensions}
@ -892,7 +893,7 @@ fraction of bends whose sum of inner angles is smaller than $180^\circ$.
\subsection{Attributes of a Single Bend}
\textsc{Compactness Index} is "the ratio of the area of the polygon over the
\textsc{compactness index} is "the ratio of the area of the polygon over the
circle whose circumference length is the same as the length of the
circumference of the polygon" \cite{wang1998line}. Given a bend, its
compactness index is calculated as follows:
@ -967,7 +968,7 @@ To find out whether two bends are similar, they are compared by 3 components:
\begin{enumerate}
\item \textsc{adjusted size} $A_{adj}$
\item \textsc{compactness index} $c$
\item \textsc{Baseline length} $l$
\item \textsc{baseline length} $l$
\end{enumerate}
Components 1, 2 and 3 represent a point in a 3-dimensional space, and Euclidean
@ -992,7 +993,7 @@ NOTE: not implemented.
\subsection{Exaggeration Operator}
NOTE: implemented, explain. Also {\texttt intersection\_tolerance} parameter.
NOTE: implemented, explain. Also {\textsc intersection\_tolerance} parameter.
\section{Program Implementation}
@ -1038,10 +1039,10 @@ Like explained in section~\ref{sec:reproducing-the-paper}, illustrations in
\inputcode{bash}{extract-and-generate}
\subsection{Function \texttt{ST\_SimplifyWV}}
\subsection{Function \textsc{st\_simplifywv}}
\inputcode{postgresql}{wm.sql}
\subsection{Function \texttt{aggregate\_rivers}}
\subsection{Function \textsc{aggregate\_rivers}}
\inputcode{postgresql}{aggregate-rivers.sql}
\end{appendices}