[Tex/LaTex] how to set and position legend in a plot with pgfplots

legendpgfplotspositioning

I want to put a legend in this two plot:

i have this code:

\begin{figure}[!ht]
\resizebox{\textwidth}{!}{
\begin{tikzpicture}
\begin{axis}[xmin=0, xmax=90,axis y line*=left,ymin=8.62,ymax=8.69, xlabel=
{Tempo [ore]}, ylabel={Pressione [bar]},title={$P_{media}$ VS 
$T_{media}$},legend style={at={(1,1)},anchor=south east}]
\addplot[thick,black] table[x=tempo,y=P_mean]
{capitolo4/grafici/t_meanVSp_mean2.txt};
\addlegendentry={Pressione}
\end{axis}
\begin{axis}[xmin=0, xmax=90,axis y line*=right,ymin=20.5,ymax=23.0, ylabel= 
{Temperatura [°C]}]
\addplot[dashed,black] table[x=tempo,y=T_mean]
{capitolo4/grafici/t_meanVSp_mean2.txt};
\addlegendentry={Temperatura}
\end{axis}  
\end{tikzpicture}
\begin{tikzpicture}
\begin{axis}[xmin=0, xmax=90,ymin=8.55,ymax=8.75,xlabel={Tempo [ore]}, 
ylabel={Pressione [bar]},title={$P_{sperimentale}$ VS $P_{ideale}$ },legend 
style={at={(1,1)},anchor=north east}]
\addplot[only marks,mark=o] table[x=tempo,y=p_sp]
{capitolo4/grafici/t_meanVSp_mean3.txt};
\addplot[thick,black] table[x=tempo,y=p_id]
{capitolo4/grafici/t_meanVSp_mean3.txt};
\legend={Psperimentale,Pideale}
\end{axis}
\end{tikzpicture}
}

but when i compile the pdf it returns this:

so it doesn't write the name of the mark in the plot and the position of the legend is not where it should be (i set south east and it prints in the north east of the plot).

Best Answer

You should really put a compilable MWE in your question. I just removed all things that depends on external packages, and I have this one:

\documentclass{standalone}
\usepackage{tikz}
\usepackage{pgfplots}\pgfplotsset{compat=1.9}
\begin{document}

\begin{tikzpicture}
\begin{axis}[xmin=0, xmax=90,axis y line*=left,ymin=8.62,ymax=8.69, xlabel=
{Tempo [ore]}, ylabel={Pressione [bar]},title={$P_{media}$ VS 
$T_{media}$},legend pos = north east]
\addplot[thick,black]  {8.63};
\legend{Pressione}
\end{axis}
\begin{axis}[xmin=0, xmax=90,axis y line*=right,ymin=20.5,ymax=23.0, ylabel= 
{Temperatura [°C]} ,legend style={at={(1,.8)},anchor=north east} ]
\addplot[dashed,black]  {x};
\legend{Temperatura}
\end{axis}  
\end{tikzpicture}
\begin{tikzpicture}
\begin{axis}[xmin=0, xmax=90,ymin=8.55,ymax=8.75,xlabel={Tempo [ore]}, 
ylabel={Pressione [bar]},title={$P_{sperimentale}$ VS $P_{ideale}$ },legend 
style={at={(1,1)},anchor=north east}]
\addplot[only marks,mark=o] {x};
\addplot[thick,black]  {x};
\legend{Psperimentale,Pideale}
\end{axis}
\end{tikzpicture}
\end{document}

which compiles to:

The main problem where the strange use of \addlegendentry= — I think you are confusing commands and keys.

You can find the information about legends in the manual, section 4.9.4 (legends), and following, at page 234 for the version 1.13.

Related Solutions

[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}

[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] plotting two time series with bounds

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

Related Question