commit c3807a1c5020d80573f3ed7fa8b8ef46fc004e12 (tree)
parent 7f00d9f37272d3b80f6285aeb0768bceb887d410
Author: Motiejus Jakštys <motiejus@uber.com>
Date: Sat, 15 May 2021 16:35:33 +0300
more analysis for 1:50k and 1:250k.
Diffstat:
| M | IV/Makefile | | | 26 | ++++++++++++++++---------- |
| M | IV/mj-msc.tex | | | 85 | +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-------------- |
2 files changed, 86 insertions(+), 25 deletions(-)
diff --git a/IV/Makefile b/IV/Makefile
@@ -40,8 +40,10 @@ RIVERS = \
salvis-visvalingam-64-chaikin-50k \
salvis-overlaid-douglas-64-chaikin-50k \
salvis-overlaid-visvalingam-64-chaikin-50k \
- salvis-wm-75-50k \
- salvis-wm-220-250k
+ salvis-wm-50k \
+ salvis-wm-250k \
+ salvis-wm-overlaid-50k-zoom \
+ salvis-wm-overlaid-250k-zoom
#################################
# The thesis, publishable version
@@ -193,15 +195,19 @@ salvis-overlaid-visvalingam-64-chaikin-50k_1COLOR = orange
salvis-overlaid-visvalingam-64-chaikin-50k_WIDTHDIV = 2
salvis-overlaid-visvalingam-64-chaikin-50k_QUADRANT = 1
-salvis-wm-75-50k_1SELECT = wm_visuals where name='salvis'
-salvis-wm-75-50k_2SELECT = wm_visuals where name='salvis-wm-75'
-salvis-wm-75-50k_1COLOR = orange
-salvis-wm-75-50k_WIDTHDIV = 2
+salvis-wm-50k_1SELECT = wm_visuals where name='salvis-wm-75'
+salvis-wm-50k_WIDTHDIV = 2
-salvis-wm-220-250k_1SELECT = wm_visuals where name='salvis'
-salvis-wm-220-250k_2SELECT = wm_visuals where name='salvis-wm-220'
-salvis-wm-220-250k_1COLOR = orange
-salvis-wm-220-250k_WIDTHDIV = 2
+salvis-wm-250k_1SELECT = wm_visuals where name='salvis-wm-220'
+salvis-wm-250k_WIDTHDIV = 10
+
+salvis-wm-overlaid-50k-zoom_1SELECT = wm_visuals where name='salvis'
+salvis-wm-overlaid-50k-zoom_2SELECT = wm_visuals where name='salvis-wm-75'
+salvis-wm-overlaid-50k-zoom_1COLOR = orange
+
+salvis-wm-overlaid-250k-zoom_1SELECT = wm_visuals where name='salvis'
+salvis-wm-overlaid-250k-zoom_2SELECT = wm_visuals where name='salvis-wm-220'
+salvis-wm-overlaid-250k-zoom_1COLOR = orange
.faux_db: db init.sql rivers.sql
bash db start
diff --git a/IV/mj-msc.tex b/IV/mj-msc.tex
@@ -1333,34 +1333,89 @@ the algorithm.
\subsection{Generalization results of Analyzed Rivers}
-Figure~\ref{fig:salvis-wm-75-50k} visualizes the generalization result for
-Šalčia and Visinčia using {\WM} with the \textsc{dhalfcircle} values from
-the table~\ref{table:scale-halfcirlce-diameter}:
+Figures~\ref{fig:salvis-wm-50k} and~\ref{fig:salvis-wm-250k} visualize
+the generalization result for Šalčia and Visinčia using {\WM} with the
+\textsc{dhalfcircle} values from the
+table~\ref{table:scale-halfcirlce-diameter}:
\begin{itemize}
- \item 1:\numprint{50000}: 75 (figure~\ref{fig:salvis-wm-75-50k}).
- \item 1:\numprint{250000}: 220 (figure~\ref{fig:salvis-wm-220-250k}).
+ \item 1:\numprint{50000}: 75.
+ \item 1:\numprint{250000}: 220.
\end{itemize}
-The original feature is orange. As can be seen, some
-isolated bends are exaggerated, and some small bends are removed.
+\subsubsection{Mid-scale (1:\numprint{50000})}
\begin{figure}[ht]
\centering
- \includegraphics[width=.5\textwidth]{salvis-wm-75-50k}
- \caption{{\WM}-generalized river (1:{\numprint{50000}}).}
- \label{fig:salvis-wm-75-50k}
+ \begin{subfigure}[b]{.49\textwidth}
+ \includegraphics[width=\textwidth]{salvis-50k}
+ \caption{Original.}
+ \end{subfigure}
+ \hfill
+ \begin{subfigure}[b]{.49\textwidth}
+ \centering
+ \includegraphics[width=\textwidth]{salvis-wm-50k}
+ \caption{Simplified.}
+ \end{subfigure}
+ \caption{Simplified with {\WM} for 1:\numprint{50000}.}
+ \label{fig:salvis-wm-50k}
+\end{figure}
+
+As one can see in figure~\ref{fig:salvis-wm-50k}, some of the small bends have
+been exaggerated, and some removed. It mostly works as expected, except some of
+the jagged lines approximately in the middle of the figure.
+Figure~\ref{fig:salvis-wm-50k-overlaid-zoom} zooms in, overlaying the original
+river (in orange).
+
+\begin{figure}[ht]
+ \centering
+ \includegraphics[width=\textwidth]{salvis-wm-overlaid-50k-zoom}
+ \caption{2x zoomed-in {\WM} for 1:\numprint{50000}.}
+ \label{fig:salvis-wm-50k-overlaid-zoom}
+\end{figure}
+
+
+These will become
+more pronounced in large-scale simplification in the next section. Other than
+some sharp edges, this algorithm works reasonably well for mid-scale
+simplification.
+
+\subsubsection{Large-scale (1:\numprint{250000})}
+
+As visible in figure~\ref{fig:salvis-wm-250k}, for large-scale map, some of the
+resulting bends look significantly exaggerated. Why is that?
+Figure~\ref{fig:salvis-wm-250k-overlaid-zoom} zooms in the large-scale
+simplification and overlays the original (in orange).
+
+\begin{figure}[ht]
+ \centering
+ \begin{subfigure}[b]{.49\textwidth}
+ \centering
+ \includegraphics[width=.2\textwidth]{salvis-250k}
+ \caption{Original.}
+ \end{subfigure}
+ \hfill
+ \begin{subfigure}[b]{.49\textwidth}
+ \centering
+ \includegraphics[width=.2\textwidth]{salvis-wm-250k}
+ \caption{Simplified.}
+ \end{subfigure}
+ \caption{Simplified with {\WM} for 1:\numprint{250000}.}
+ \label{fig:salvis-wm-250k}
\end{figure}
\begin{figure}[ht]
\centering
- \includegraphics[width=.5\textwidth]{salvis-wm-220-250k}
- \caption{{\WM}-generalized river (1:{\numprint{250000}}).}
- \label{fig:salvis-wm-220-250k}
+ \includegraphics[width=\textwidth]{salvis-wm-overlaid-250k-zoom}
+ \caption{10x zoomed-in {\WM} for 1:\numprint{250000}.}
+ \label{fig:salvis-wm-250k-overlaid-zoom}
\end{figure}
-% TODO: expand section and remove clear-page.
-\clearpage
+A conglomeration of bends is visible, especially in north-east side of the
+center. We assume this was caused by two bends significantly exaggerated,
+leaving no space to exaggerate for those between the two. For the same reason,
+the 1:\numprint{50000} figure~\ref{fig:salvis-wm-50k} has many smaller bends
+at approximately the same location.
\subsection{Generalization result comparison with national spatial data sets}
