From a26ae88e866c32a62e3326e39c9e0add901efb0a Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Motiejus=20Jak=C5=A1tys?= Date: Mon, 26 Apr 2021 11:54:00 +0300 Subject: [PATCH] explain big-O notation better --- IV/mj-msc.tex | 34 +++++++++++++++++++++------------- 1 file changed, 21 insertions(+), 13 deletions(-) diff --git a/IV/mj-msc.tex b/IV/mj-msc.tex index 60cdd5e..400e015 100644 --- a/IV/mj-msc.tex +++ b/IV/mj-msc.tex @@ -205,7 +205,7 @@ thus convenient to analyze for both small and large scale generalization. \includegraphics[width=.2\textwidth]{salvis-250k} \caption{Example scaled 1:250000.} \end{subfigure} - \caption{Down-scaled original river (1:50000 and 1:250000).} + \caption{Down-scaled original river.} \label{fig:salvis-50-250} \end{figure} @@ -339,12 +339,12 @@ This section defines vocabulary and terms as defined in the rest of the paper. \item[Vertex] is a point on a plane, can be expressed by a pair of $(x,y)$ coordinates. - \item[Line Segment (or Segment)] joins two vertices by a straight line. A - segment can be expressed by two coordinate pairs: $(x_1, y_1)$ and - $(x_2, y_2)$. Line Segment and Segment are used interchangeably + \item[Line Segment] or \textsc{segment} joins two vertices by a straight + line. A segment can be expressed by two coordinate pairs: $(x_1, y_1)$ + and $(x_2, y_2)$. Line Segment and Segment are used interchangeably throughout the paper. - \item[Line], or \textsc{linestring}, represents a single linear feature in + \item[Line] or \textsc{linestring}, represents a single linear feature in the real world. For example, a river or a coastline. Geometrically, A line is a series of connected line segments, or, @@ -354,21 +354,29 @@ This section defines vocabulary and terms as defined in the rest of the paper. \item[Bend] is a subset of a line that humans perceive as a curve. The geometric definition is complex and is discussed in - section~\onpage{sec:definition-of-a-bend}. + section~\ref{sec:definition-of-a-bend}. \item[Baseline] is a line between bend's first and last vertex. \item[Sum of inner angles] TBD. \item[Algorithmic Complexity] also called \textsc{big o notation}, is a - relative measure to explain how long will the algorithm run depending - on it's input. For example, given $n$ objects and time complexity of - $O(n)$, the time it takes to execute the algorithm is proportional to - $n$. Conversely, if complexity is $O(n^2)$, then the time it takes to - execute the algorithm is quadratic. $O$ notation was first suggested by + relative measure to explain how long will the algorithm runs depending + on it's input. It is widely used in computing science when discussing + the efficiency of a given algorithm. + + For example, given $n$ objects and time complexity of $O(log(n))$, the + time it takes to execute the algorithm is logarithmic to $n$. + Conversely, if complexity is $O(n^2)$, then the time it takes to + execute the algorithm is quadratic depending on the input. Importantly, + if the input size doubles, the time it takes to run the algorithm + quadruples. + + $O$ notation was first suggested by Bachmann\cite{bachmann1894analytische} and - Laundau\cite{landau2000handbuch} in late XIX'th century, and adopted - for computer science by Donald Knuth\cite{knuth1976big} in 1970s. + Landau\cite{landau2000handbuch} in late XIX'th century, and clarified + and popularized for computing science by Donald + Knuth\cite{knuth1976big} in the 1970s. \end{description}