commit bd6e3647d5754df63ce5b639b0c110f57e13b5b6 (tree)
parent 58d479c1b356893f40323c1036b345a9b489b74d
Author: Motiejus Jakštys <desired.mta@gmail.com>
Date: Wed, 27 May 2020 13:41:27 +0300
bends
Diffstat:
1 file changed, 23 insertions(+), 11 deletions(-)
diff --git a/II/Referatas/mj-referatas.tex b/II/Referatas/mj-referatas.tex
@@ -160,21 +160,21 @@ page~\pageref{fig:zeimena}) will be used as inputs to the generalization
algorithms, because the river exhibits both both straight and curved shape, is
a combination of two curly rivers, and author's familiarity with the location.
-Since the map area is large (approx. 20km by 28km, scale $1:150 000$), we will
+Since the map area is large (approx. 20km by 28km, scale $1:300 000$), we will
also review a subset of the area of approx 2200m by 1575m. The zoomed-in
version will help explain some of the deficiencies in the reviewed algorithms.
\begin{figure}[h]
\centering
\includegraphics[width=67.5mm]{zeimena}
- \caption{Lakaja and Žeimena, with marked river crossing area, $1:300000$}
+ \caption{Lakaja and Žeimena, with marked river crossing area, $1:300 000$}
\label{fig:zeimena}
\end{figure}
\begin{figure}[h]
\centering
\includegraphics[width=74mm]{crossing}
- \caption{River crossing area zoomed in, $1:30000$}
+ \caption{River crossing area zoomed in, $1:30 000$}
\label{fig:crossing}
\end{figure}
@@ -196,7 +196,7 @@ researched.
As can be observed in table~\ref{tab:comparison-zeimena} on
page~\pageref{tab:comparison-zeimena}, both simplication algorithms convert
-bends to chopped lines. This is especially visible in tolerances 250 and 500.
+bends to chopped lines. This is especially visible in tolerances 256 and 512.
In a more robust simplification algorithm, the larger tolerance, the larger the
bends on the original map should be retained.
@@ -215,7 +215,7 @@ bends on the original map should be retained.
\includegraphics[width=.5\linewidth]{zeimena-douglas-256} &
\includegraphics[width=.5\linewidth]{zeimena-visvalingam-256} \tabularnewline \hline
- 512/ 262144 &
+ 512/262144 &
\includegraphics[width=.25\linewidth]{zeimena-douglas-512} &
\includegraphics[width=.25\linewidth]{zeimena-visvalingam-512} \tabularnewline \hline
@@ -235,8 +235,22 @@ bends on the original map should be retained.
\label{tab:comparison-zeimena}
\end{figure}
-Let's zoom in to the river crossing area for some of the algorithms.
+Let's zoom in to the river crossing area for some of the algorithms; see
+table~\ref{tab:comparison-crossing} on page~\pageref{tab:comparison-crossing}.
+Both {\VW} and {\DP} simplify "blunt" bends (a "blunt" bent looks like a cutout
+from a large circle, see figure~\ref{blunt-bent} on page~\pageref{blunt-bent}.
+
+\begin{figure}[h]
+ \centering
+ \begin{tikzpicture}
+ \draw (-5,0) -- (-3, 0) ;
+ \draw (0,0) arc (60:120:3) ;
+ \draw (0,0) -- (2, 0) ;
+ \end{tikzpicture}
+ \caption{Blunt bent}
+ \label{fig:blunt-bent}
+\end{figure}
\begin{figure}[h]
\renewcommand{\tabularxcolumn}[1]{>{\center\small}m{#1}}
@@ -249,22 +263,20 @@ Let's zoom in to the river crossing area for some of the algorithms.
\includegraphics[width=\linewidth]{overlaid-zeimena-douglas-64} &
\includegraphics[width=\linewidth]{overlaid-zeimena-visvalingam-64} \tabularnewline \hline
- 125/15625 &
+ 128/16384 &
\includegraphics[width=\linewidth]{overlaid-zeimena-douglas-128} &
\includegraphics[width=\linewidth]{overlaid-zeimena-visvalingam-128} \tabularnewline \hline
- 250/62500 &
+ 256/65536 &
\includegraphics[width=\linewidth]{overlaid-zeimena-douglas-256} &
\includegraphics[width=\linewidth]{overlaid-zeimena-visvalingam-256} \tabularnewline \hline
\end{tabularx}
\caption{{\DP} and {\VW} on river crossing area}
- \label{tab:comparison-zoomed}
+ \label{tab:comparison-crossing}
\end{figure}
-
-
To sum up, both {\VW} and {\DP} simplify the lines, but their cartographic
output poorly represents lines and bends. Where to look for better output?
