Several typos fixed, cheers @AnnaLisa12345

fixes #23

bathymetry/bathymetry.tex

@@ -291,7 +291,7 @@ \subsection{TIN simplification}
 
 %%%
 %
-\subsubsection{The smoothing operator}%
+\subsection{The smoothing operator}%
 \label{chap:myapproach:smoothing}
 
 The smoothing operator basically estimates, with the Laplace interpolant (see Section~\ref{sec:laplace} on page~\pageref{sec:laplace}), the depth of each vertex in a dataset by considering its natural neighbour (see Figure~\ref{fig:1Dsmoothop}).
@@ -340,7 +340,7 @@ \subsubsection{The smoothing operator}%
 
 %%%
 %
-\subsubsection{The densification operator}%
+\subsection{The densification operator}%
 \label{sec:densification}
 
 Its objective is primarily to minimise the discretisation error between the Laplace interpolated field and the contours that are extracted from the DT, this is illustrated in Figure~\ref{fig:1Ddensop}.

conversion/conversion.tex

@@ -418,7 +418,7 @@ \section{Exercises}
 
 \begin{enumerate}
   \item When converting isolines to a TIN, what main ``problem'' should you be aware of? Describe \emph{in details} one algorithm to convert isolines (given for instance in a \emph{shapefile}) to a TIN and avoid this problem.
-  \item How would the isocontours of a 2.75D terrain look like?
+  \item What would the isocontours of a 2.75D terrain look like?
   \item In Section~\ref{sec:structuring}, it is mentioned that merging the segments will form on polygon. But how to ensure that the orientation of that resulting curve is consistent, that it is for instance having higher terrains on the right?
   \item Given a raster terrain (GeoTiff format) that contains several cells with \texttt{no\_data} values, describe the methodology you would use to extract contour lines from it. As a reminder, contours lines should be closed curves, except at the boundary of the dataset.
   \item Assume you have the small terrain formed of 3 triangles below, draw the isoline in this TIN for an elevation of 10m.

dtvd/dtvd.tex

@@ -574,8 +574,7 @@ \section{Notes and comments}%
 Since a DT can be locally modified by adding one point (and not reconstructing the whole structure from scratch, see Figure~\ref{fig:insertion_deletion}), it is also possible to delete/remove one vertex from a DT with only local operations.
 \citet{Mostafavi03} and \citet{Devillers09} describe algorithms.
 
-
-
+The details of how the spatial interpolation methods generalise to 3D are given in \citet{Ledoux05}.
 
 %%%
 %
@@ -586,7 +585,7 @@ \section{Exercises}
   \item If a given vertex $v$ in a DT has 7 incident triangles, how many vertices will its dual polygon contain?
   \item A DT has 6 vertices, and 3 of these are forming the convex hull. How many triangles does the DT have?
   \item Assume you have 8 points located on a circle. Draw the DT and the VD of these 8 points.
-  \item When inserting points in a DT (Algorithm~\ref{algo:insert1pt}), what happens if a new points is inserted directly on an edge? Line~2 states that the triangle is split into 3 new triangles, does it still hold?
+  \item When inserting points in a DT (Algorithm~\ref{algo:insert1pt}), what happens if a new point is inserted directly on an edge? Line~2 states that the triangle is split into 3 new triangles, does it still hold?
   \item Given the input formed of elevation points and breaklines below (both projected to the $xy$-plane), draw both the constrained and conforming Delaunay triangulation (an approximation is fine).
   \\ \\
   \centering{\includegraphics[width=0.95\linewidth]{figs/cdt_exercise}}

front-back/preface.tex

@@ -32,7 +32,7 @@ \chapter*{Preface}
 
 \paragraph*{Acknowledgements.}
 We thank Balázs Dukai for help in proof-reading, and all the students of the first year of the course (2018--2019) who helped by pointing out errors and typos.
-Also, the following students of the course all made pull requests to fix errors/typos: Chen Zhaiyu, Ardavan Vameghi, Li Xiaoai, Ivan Pađen.
+Also, the following students of the course all made pull requests to fix errors/typos: Chen Zhaiyu, Ardavan Vameghi, Li Xiaoai, Ivan Pađen, Anna Lisa Labaar.
 
 
 

interpol/interpol.tex

@@ -601,7 +601,7 @@ \section{Exercises}
   \item Given a triangle $\tau$ with coordinates (20.0, 72.0, 21.0), (116.0, 104.0, 32.0), and (84.0, 144.0, 26.0), estimate the elevation at $x$ = (92.0, 112.0) with linear interpolation in the triangle (both by finding the equation of the plane and with barycentric coordinates).
   \item What happens when the search distance is very large for inverse distance weighting interpolation (IDW)?
   \item For grids, can IDW or others be used instead of bilinear? If yes, how does that work?
-  \item The 15 elevation samples below have been collected. You want to interpolate at two location:
+  \item The 15 elevation samples below have been collected. You want to interpolate at two locations:
   \begin{enumerate}
     \item at location ($7,6$) with IDW (radius=3; power=2); the purple circle.
     \item at location ($15,6$) with linear interpolation in TIN; the orange cross.

massive/massive.tex

@@ -24,7 +24,7 @@ \chapter{Handling massive terrains}
 
 %
 
-For the purposes of this course, we define as ``massive'' a dataset that does not fit into the main memory of a standard computer, which is usually around 16GB\@.
+For the purpose of this course, we define as ``massive'' a dataset that does not fit into the main memory of a standard computer, which is usually around 16GB\@.
 This definition makes practical sense because working with data outside of the main memory of a computer is substantially slower (about 2 orders of magnitude for solid state drives and 5 for hard drives), causing many standard data processing algorithms to become impractical with massive datasets.
 Keep in mind that not only the ($xyz$) coordinates of the points of a point cloud need to be stored, but also often attributes for each point (LAS has several standard ones).
 Also, in the case of TINs, the geometry of the triangles---and potentially the topological relationships between them---need to be explicitly stored.
@@ -298,7 +298,7 @@ \section{Exercises}
 
 \begin{enumerate}
   \item \citet{Isenburg06-1} argues that real-world point cloud datasets often have natural spatial coherence. Explain why that is for lidar datasets.
-  \item Given a simple point clouds stored in a CSV file (one $x,y,z$ per line), how many passes over the file the triangulator of \citet{Isenburg06-1} make? What does each do?
+  \item Given a simple point cloud stored in a CSV file (one $x,y,z$ per line), how many passes over the file does the triangulator of \citet{Isenburg06-1} make? What does each do?
   \item How to construct a $k$d-tree that is as balanced as possible?
   \item ``The ideas behind streaming are very useful for certain \emph{local} problems, but unfortunately they cannot be used directly for \emph{global} problems such as visibility or flow modelling''. Explain why that is with a concrete example.
 \end{enumerate}

whatisterrain/whatisterrain.tex

@@ -439,7 +439,7 @@ \section{Notes and comments}
 \section{Exercises}
 
 \begin{enumerate}
-  \item Explain in our own words why a point cloud (\eg\ collected with airborne lidar) is not considered a complete representation of a terrain.
+  \item Explain in your own words why a point cloud (\eg\ collected with airborne lidar) is not considered a complete representation of a terrain.
   \item What is a bivariate function? 
   \item Assume you have a 2.75D terrain of an area. Is it possible to extract the isolines from it? What properties will these have? Will they intersect?
 \end{enumerate}