[Tex/LaTex] Label plots in pgfplots without entering coordinates manually

pgfplots

I like to label my plots directly, i.e. without using a legend, but instead using a pin node. So far, I have added the labels with manually specified coordinates, which means trial-and-error for data plots. A better way would be to let TikZ handle the positioning, but I don't know how to access the paths of the plots. Is there a way of adding a node to a plot in pgfplots, similar to the [pos=0.5] option for normal paths? Just adding node [pos=0.5] {x} to the \addplot command does not position the node on the line, but instead at some location in the lower left of the plot area, regardless of the pos value.

MWE:

\documentclass{article}
\usepackage{pgfplots}
\begin{document}
\begin{tikzpicture}
\begin{axis}
\addplot {x^2} node [pos=0.75,pin={-10:$x^2$},inner sep=0pt] {}; % This does not position the node on the line
\addplot {1.5*x^2};
\node at (axis cs:4,16) [pin={-10:$x^2$},inner sep=0pt] {}; % This is what I want, but without calculating the coordinates by hand
\node at (axis cs:4,24) [pin={170:$1.5 x^2$},inner sep=0pt] {};
\end{axis}
\end{tikzpicture}
\end{document}

pgfplots plot with nodes annotating the lines

Best Answer

The current version of pgfplots (>= 1.5.1) supports this as you expected it in the first place (i.e. using node[pos=0.75]):

enter image description here

\documentclass{article}
\usepackage{pgfplots}
\begin{document}
\thispagestyle{empty}
\begin{tikzpicture}
\begin{axis}
\addplot {x^2} node [pos=0.75,pin={-10:$x^2$},inner sep=0pt] {};
\addplot {1.5*x^2} node [pos=0.75,pin={170:$1.5 x^2$},inner sep=0pt] {};
\end{axis}
\end{tikzpicture}


\begin{tikzpicture}
 \begin{axis}[
        axis y line=center,
        axis x line=middle, 
        axis on top=true,
        xmin=-7,
        xmax=7,
        ymin=-4,
        ymax=4,
        clip=false
] 

\addplot[
    mark=none,
    domain=-4:6,
    samples=80,
    red,
    thick,
] {(x<-2)*-2 + (!(x<-2) && (x<3))*x + (!(x<3)) * 3}
    node[pos=0.1,pin=135:{\color{purple}$f(x)=-2$}] {}
    node[pos=0.6,pin=135:{\color{blue}$f(x)=x$}] {}
    node[pos=0.9,pin=135:{\color{green!70!black}$f(x)=3$}] {}
;
\end{axis}
\end{tikzpicture}

\end{document}

It is available for download on http://pgfplots.sourceforge.net/

Code

\documentclass[a4paper]{article}
\usepackage{fullpage}
\usepackage{pgfplots}
\usepackage{pgfplotstable}

\pgfplotstableread{
0 10 12
1 10 11
2 8  9
3 15 16
4 13 15
5 20 21
}\tableA

\pgfplotstableread{
2 20 23
3 19 21
4 20 22
}\tableB

\begin{document}
    \begin{center}
        \begin{tikzpicture}
            \begin{axis}
            [   stack plots=y,
                area style,
                enlarge x limits=false,
                xmin=0,
                xmax=5,
                ymin=0,
                ymax=25,
            ]
                \addplot[fill=none,draw=none] table[y expr={\thisrowno{1}}] {\tableA} \closedcycle;
                \addplot[fill=blue!30!,draw=none] table[y expr={\thisrowno{2}-\thisrowno{1}}] {\tableA} \closedcycle;

            \end{axis}
            \begin{axis}
            [   stack plots=y,
                area style,
                enlarge x limits=false,
                xmin=0,
                xmax=5,
                ymin=0,
                ymax=25,
                hide axis,
            ]
                \addplot[fill=none,draw=none] table[y expr={\thisrowno{1}}] {\tableB} \closedcycle;
                \addplot[fill=blue!30!,draw=none] table[y expr={\thisrowno{2}-\thisrowno{1}}] {\tableB} \closedcycle;

            \end{axis}
        \end{tikzpicture}
    \end{center}
\end{document}

Result

enter image description here

[Tex/LaTex] plotting two time series with bounds

This happens because PGFPlots only uses one "stack" per axis: You're stacking the second confidence interval on top of the first. The easiest way to fix this is probably to use the approach described in "Is there an easy way of using line thickness as error indicator in a plot?": After plotting the first confidence interval, stack the upper bound on top again, using stack dir=minus. That way, the stack will be reset to zero, and you can draw the second confidence interval in the same fashion as the first:

\documentclass{standalone}
\usepackage{pgfplots, tikz}

\usepackage{pgfplotstable}

\pgfplotstableread{
temps   y_h y_h__inf    y_h__sup    y_f y_f__inf    y_f__sup    

1   0.237340    0.135170    0.339511    0.237653    0.135482    0.339823    
2   0.561320    0.422007    0.700633    0.165871    0.026558    0.305184    
3   0.694760    0.534205    0.855314    0.074856    -0.085698   0.235411    
4   0.728306    0.560179    0.896432    0.003361    -0.164765   0.171487    
5   0.711710    0.544944    0.878477    -0.044582   -0.211349   0.122184    
6   0.671241    0.511191    0.831291    -0.073347   -0.233397   0.086703    
7   0.621177    0.471219    0.771135    -0.088418   -0.238376   0.061540    
8   0.569354    0.431826    0.706882    -0.094382   -0.231910   0.043146    
9   0.519973    0.396571    0.643376    -0.094619   -0.218022   0.028783    
10  0.475121    0.366990    0.583251    -0.091467   -0.199598   0.016664    
}{\table}

\begin{document}
\begin{tikzpicture}

    \begin{axis}
    % y_h confidence interval
    \addplot [stack plots=y, fill=none, draw=none, forget plot]   table [x=temps, y=y_h__inf]   {\table} \closedcycle;
    \addplot [stack plots=y, fill=gray!50, opacity=0.4, draw opacity=0, area legend]   table [x=temps, y expr=\thisrow{y_h__sup}-\thisrow{y_h__inf}]   {\table} \closedcycle;
    % subtract the upper bound so our stack is back at zero
    \addplot [stack plots=y, stack dir=minus, forget plot, draw=none] table [x=temps, y=y_h__sup] {\table};

    % y_f confidence interval
    \addplot [stack plots=y, fill=none, draw=none, forget plot]   table [x=temps, y=y_f__inf]   {\table} \closedcycle;
    \addplot [stack plots=y, fill=gray!50, opacity=0.4, draw opacity=0, area legend]   table [x=temps, y expr=\thisrow{y_f__sup}-\thisrow{y_f__inf}]   {\table} \closedcycle;

    % the line plots (y_h and y_f)    
    \addplot [stack plots=false, very thick,smooth,blue]  table [x=temps, y=y_h]   {\table};
    \addplot [stack plots=false, very thick,smooth,blue]  table [x=temps, y=y_f]   {\table};
    \end{axis}

\end{tikzpicture}
\end{document}

Best Answer

Related Solutions

[Tex/LaTex] Using pgfplots, is there a way to overlay multiple stacked plots with different ranges

Code

Result

[Tex/LaTex] plotting two time series with bounds

Related Question