LaTeX: graphs with coordinates input

In one of my previous posts I wrote about plotting LaTeX function graphs using pgfplots. But sometimes you don’t have a function rule, but just a set of data points.

Using pgfplots you can easily plot a function using those coordinates. The following Tex code will draw a line through each of the data points.

\begin{tikzpicture}[>=stealth]

\begin{axis}[
height=\textwidth/1.5,
width=\textwidth/1.5,
xmin=0,xmax=4,
ymin=0,ymax=9,
axis x line=middle,
axis y line=middle,
axis line style=->,
xlabel={$x$},
ylabel={$y$},
]

% plot some coordinates
\addplot[mark=*, blue, line width=1pt] coordinates {
(0,   4)
(0.5, 6)
(1,   2)
(1.5, 3.5)
(2,   4)
(2.5, 6)
(3,   5)
(3.5, 3)
(4,   5.5)
};

\end{axis}

\end{tikzpicture}

Which will yield the following result:

Naturally you can draw a line without printing dots in the points, you just set mark=none.