[Tex/LaTex] Annotate Plots in TikZ/PGFplots

pgfplotstikz-pgf

I have the following piece of code in my tex file.

\documentclass{standalone}
\usepackage{pgfplots}

\begin{document}
\begin{tikzpicture}[scale=2]
\tikzstyle{every node}=[font=\scriptsize]
\definecolor{mycolor1}{rgb}{0,0.5,0}

\begin{loglogaxis}[
ultra thick,
xshift=1.7in,
scale only axis,
width=1.2in,
height=1.25in,
xmin=2500, xmax=1000000,
ymin=1, ymax=1e7,
axis on top,
xlabel=Number of unknowns,
xlabel style={at={(0.125,-0.025)},anchor=south west},
ylabel=Time taken in seconds,
ylabel style={at={(0.22,0.125)},anchor=south west},
x tick label style={yshift=-3},
y tick label style={xshift=-2}]

\addplot [
color=red,
solid
]
coordinates{
(2500, 2)(10000, 6)(62500, 40)(250000, 155)(1000000, 600)
};

\addplot [
color=green,
solid
]
coordinates{
(2500, 52)(10000, 832)(62500, 32500)(250000, 520000)(1000000, 8320000)
};
\end{loglogaxis}
\end{tikzpicture}
\end{document}

The output is

enter image description here

I want to indicate on the figure that the red line is $10^4$ times faster than the green line by drawing an arrow between the two lines at the right extreme and writing $\times 10000$. How should I proceed?

Thanks

Best Answer

There are more than one way of doing it but using the axis coordinate system seems the easiest for me.

\documentclass{standalone}
\usepackage{pgfplots}
\tikzstyle{every node}=[font=\scriptsize]
\definecolor{mycolor1}{rgb}{0,0.5,0}
\begin{document}
\begin{tikzpicture}[scale=2]    
\begin{loglogaxis}[
clip=false, %<---- Notice this option
ultra thick,
xshift=1.7in,
scale only axis,
width=1.2in,
height=1.25in,
xmin=2500, xmax=1000000,
ymin=1, ymax=1e7,
axis on top,
xlabel=Number of unknowns,
%xlabel style={at={(0.125,-0.025)},anchor=south west},
ylabel=Time taken in seconds,
%ylabel style={at={(0.22,0.125)},anchor=south west},
%x tick label style={yshift=-3},
%y tick label style={xshift=-2}
]

\addplot [color=red,solid]coordinates{(2500, 2)(10000, 6)(62500, 40)(250000, 155)(1000000, 600)};
\addplot [color=green,solid] coordinates{(2500, 52)(10000, 832)(62500, 32500)(250000, 520000)(1000000, 8320000)};
\draw[-latex,thick] (axis cs:2e6,1e3) -- (axis cs:2e6,1e7) node[right,midway] {$\times 10^4$};
\end{loglogaxis}
\end{tikzpicture}
\end{document}

enter image description here

Related Solutions

[Tex/LaTex] Clipping plots to other plots in pgfplots

Instead of drawing the frame using \addplot, you can create a TikZ path which describes the same shape using the plot and --plot operations. This allows you to use the clip key to restrict all drawing inside the current scope to the area described by the path. In order to use the TikZ plot operation with PGFPlots coordinates, you need to use the axis cs coordinate system.

When the scope ends, so does the clipping, as shown by the red path:

Clipped plots

\documentclass[tikz,margin=3pt]{standalone}
\usepackage{tikz,pgfplots}
    \usetikzlibrary{pgfplots.polar,intersections}
    \pgfplotsset{compat=newest}

\begin{document}
\begin{tikzpicture}
\begin{polaraxis}[samples=50,smooth,thick,axis lines=none]

\begin{scope} % Everything inside this scope is clipped
% frame
\path[clip,draw]
    plot[domain=44.9:135] (axis cs: \x, {(4/sin(\x))/(1+0.2*(4/sin(\x)))})
    --plot[domain=135:225] (axis cs: \x, {(-4/cos(\x))/(1+0.2*(-4/cos(\x)))})
    --plot[domain=225:315] (axis cs: \x, {(-4/sin(\x))/(1+0.2*(-4/sin(\x)))})
    --plot[domain=-45:45] (axis cs: \x, {(4/cos(\x))/(1+0.2*(4/cos(\x)))})
    --cycle;

% Clipped plot:
\addplot[dotted,domain=30:150]{(3/sin(x))/(1+0.2*(3/sin(x)))};
\end{scope}

% Scope ended, so this is not clipped:
\addplot[red,dotted,domain=20:160]{(2/sin(x))/(1+0.2*(2/sin(x)))};
\end{polaraxis}
\end{tikzpicture}
\end{document}

It also works when you square the second part of the quotients:

With squared quotients

\documentclass[tikz,margin=3pt]{standalone}
\usepackage{tikz,pgfplots}
    \usetikzlibrary{pgfplots.polar,intersections}
    \pgfplotsset{compat=newest}

\begin{document}
\begin{tikzpicture}
\begin{polaraxis}[samples=50,smooth,thick,axis lines=none]

\begin{scope} % Everything inside this scope is clipped
% frame
\path[clip,draw]
    plot[domain=44.9:135] (axis cs: \x, {(4/sin(\x))/(1+0.01*(4/sin(\x))^2)})
    --plot[domain=135:225] (axis cs: \x, {(-4/cos(\x))/(1+0.01*(-4/cos(\x))^2)})
    --plot[domain=225:315] (axis cs: \x, {(-4/sin(\x))/(1+0.01*(-4/sin(\x))^2)})
    --plot[domain=-45:45] (axis cs: \x, {(4/cos(\x))/(1+0.01*(4/cos(\x))^2)})
    --cycle;

% Clipped plot:
\addplot[dotted,domain=30:150]{(3/sin(x))/(1+0.01*(3/sin(x))^2)};
\end{scope}

% Scope ended, so this is not clipped:
\addplot[red,dotted,domain=20:160]{(2/sin(x))/(1+0.01*(2/sin(x))^2)};
\end{polaraxis}
\end{tikzpicture}
\end{document}

[Tex/LaTex] How to hide empty (value 0) ybars with pgfplots

You can use

 y filter/.expression={y==0 ? nan : y}

in the options of \addplot.

\documentclass{article}

% ---------------------------------- tikz
\usepackage{pgfplots}          % to print charts
\pgfplotsset{compat=1.12}

\begin{document}

\begin{figure}
  \centering
  \begin{tikzpicture}
    \begin{axis} [
      % general
      ybar,
      scale only axis,
      height=0.5\textwidth,
      width=1.2\textwidth,
      ylabel={\# Dots},
      nodes near coords,
      xlabel={Variation},
      xticklabel style={
        rotate=90,
        anchor=east,
      },
      %enlarge x limits={abs value={3}},
      ]
      \addplot+[y filter/.expression={y==0 ? nan : y}] table [
        x=grade,
        y=value,
      ] {
grade   value
-11 0
-10 0
-9  0
-8  0
-7  0
-6  0
-5  3
-4  1
-3  2
-2  15
-1  11
0   179
1   8
2   1
3   0
4   1
5   2
6   0
7   0
8   0
9   0
10  0
11  0
      };
    \end{axis}
  \end{tikzpicture}
\end{figure}
\end{document}

Best Answer

Related Solutions

[Tex/LaTex] Clipping plots to other plots in pgfplots

[Tex/LaTex] How to hide empty (value 0) ybars with pgfplots

Related Question