How to make lines joining point a target - tikzpicture

Question

I have been able to do the code below but it is still not what I need.

I need points a1 through a5 to form a straight line to the point "Gol".

How do I do that?

The .dat files look like this (inimigo.dat):

52 10 a0
3 41 a1
51 52 a2
22 62 a3
36 32 a4

pontofixo.dat

115 45 Goal

gbest.data

66.6357 27.6357 g0
48.2417 38.2417 g1
53.5413 63.5413 g2
57.8469 18.8469 g3
75.6483 40.2518 g4

inicial.dat

65  26  i0
47  37  i1
6   16  i2
44  5   i3
58  6   i4

Taking these coordinates, how to make a line from point a0 to point "Gol"?

\documentclass[varwidth]{standalone}
\usepackage{caption}
\usepackage{subcaption}
\usepackage{pgfplots}
\pgfplotsset{compat=newest}
\usepackage{geometry}
\geometry{
 paperwidth=25cm,
 left=1in,right=1in,top=1in,bottom=1in
}
\begin{document}
\begin{figure}[h]
\centering
\begin{subfigure}{.4\textwidth}
  \centering
  \begin{tikzpicture}
  \begin{axis}[xmin=0,xmax=120,ymin=0,ymax=90, xstep=1,ystep=1,nodes near coords,enlargelimits=0.0]

     \addplot +[only marks,mark=*,nodes near coords={\labelz}, visualization depends on={value \thisrowno{2}\as\labelz}] 
               table[header=false]{pontofixo.dat};

    \addplot +[only marks,mark=*,nodes near coords={\labelz}, visualization depends on={value \thisrowno{2}\as\labelz}] 
                table[header=false]{inimigo.dat};

        \addplot +[only marks,mark=*,nodes near coords={\labelz},visualization depends on={value \thisrowno{2}\as\labelz}] 
                table[header=false]{inicial.dat};

  \end{axis}
  \end{tikzpicture}
\caption{Estado inicial}
\end{subfigure}%
\centering
\begin{subfigure}{.4\textwidth}
  \centering
  \begin{tikzpicture}
  \begin{axis}[xmin=0,xmax=120,ymin=0,ymax=90, xstep=1,ystep=1,nodes near coords,enlargelimits=0.0]

     \addplot +[only marks,mark=*,nodes near coords={\labelz}, visualization depends on={value \thisrowno{2}\as\labelz}] 
               table[header=false]{pontofixo.dat};

    \addplot +[only marks,mark=*,nodes near coords={\labelz}, visualization depends on={value \thisrowno{2}\as\labelz}] 
                table[header=false]{inimigo.dat};

       \addplot +[only marks,mark=*,nodes near coords={\labelz}, visualization depends on={value \thisrowno{2}\as\labelz}] 
                table[header=false]{gbest.dat};
  \end{axis}
  \end{tikzpicture}
  \caption{Estado final}
\end{subfigure}%
\end{figure}
\end{document}

This obtain this result:

but I need similar (edit in inskcape):

Answer 1

COMPLETE REVISION: Some time after I answered this question, I came across this cool trick, which allows one to achieve the goal in a much more elegant way. After I got reminded of my original code in this question, I felt that I need to update this answer to

\documentclass[varwidth]{standalone}
\usepackage{filecontents}
\begin{filecontents*}{inimigo.dat}
x y label
52 10 a0
3 41 a1
51 52 a2
22 62 a3
36 32 a4
\end{filecontents*}
\begin{filecontents*}{pontofixo.dat}
x y label
115 45 Goal
\end{filecontents*}
\begin{filecontents*}{inicial.dat}
x y label
65  26  i0
47  37  i1
6   16  i2
44  5   i3
58  6   i4
\end{filecontents*}
\usepackage{caption}
\usepackage{subcaption}
\usepackage{pgfplots}
\pgfplotsset{compat=newest}
\usepackage{geometry}
\geometry{
 paperwidth=25cm,
 left=1in,right=1in,top=1in,bottom=1in
}
\pgfplotsset{% https://tex.stackexchange.com/a/75811/121799
    name nodes near coords/.style={
        every node near coord/.append style={
            name=#1-\coordindex,
            alias=#1-last,
        },
    },
    name nodes near coords/.default=coordnode
}
\begin{document}
\begin{figure}[h]
\centering
\begin{subfigure}{.4\textwidth}
  \centering
  \begin{tikzpicture}
  \begin{axis}[xmin=0,xmax=120,ymin=0,ymax=90, xstep=1,ystep=1,nodes near coords,enlargelimits=0.0]

    \addplot +[only marks,mark=*,nodes near
     coords={\labelz}, 
     visualization depends on={value \thisrowno{2}\as\labelz},
     name nodes near coords=Gol] 
               table{pontofixo.dat}; % this defines the coordinate (Goal)
               % if I do not define it, the next sequence will throw an error
    \addplot +[scatter/position=relative,only marks,mark=*,
    nodes near coords={\labelz}, 
    visualization depends on={value \thisrowno{2}\as\labelz},
    name nodes near coords=a] 
                table{inimigo.dat};

    \addplot +[scatter/position=relative,only marks,mark=*,
    nodes near coords={\labelz}, 
    visualization depends on={value \thisrowno{2}\as\labelz},
    name nodes near coords=i] 
                table{inicial.dat};


  \end{axis}
 \foreach \n in {0,...,4}
 {
 \draw[black,thick,dashed] (a-\n.south) -- (Gol-0.south);
 \draw[black,thick,dashed] (i-\n.south) -- (Gol-0.south);
 }
  \end{tikzpicture}
\caption{Estado inicial}
\end{subfigure}%
\centering
\begin{subfigure}{.4\textwidth}
  \centering
  \begin{tikzpicture}
  \begin{axis}[xmin=0,xmax=120,ymin=0,ymax=90, xstep=1,ystep=1,nodes near coords,enlargelimits=0.0]

     \addplot +[only marks,mark=*,nodes near
     coords={\labelz}, 
     visualization depends on={value \thisrowno{2}\as\labelz},
     name nodes near coords=Gol] 
               table{pontofixo.dat}; % this defines the coordinate (Goal)
               % if I do not define it, the next sequence will throw an error
    \addplot +[scatter/position=relative,only marks,mark=*,
    nodes near coords={\labelz}, 
    visualization depends on={value \thisrowno{2}\as\labelz},
     name nodes near coords=a] 
                table{inimigo.dat};

    \addplot +[scatter/position=relative,only marks,mark=*,
    nodes near coords={\labelz}, 
    visualization depends on={value \thisrowno{2}\as\labelz},
    name nodes near coords=g] 
                table{gbest.dat};

  \end{axis}
 \foreach \n in {0,...,4}
 {
 \draw[black,thick,dashed] (a-\n.south) -- (Gol-0.south);
 \draw[black,thick,dashed] (g-\n.south) -- (Gol-0.south);
 }
 \end{tikzpicture}
 \caption{Estado final}
\end{subfigure}%
\end{figure}
\end{document}

OLD: Here is my original solution.

\documentclass[varwidth]{standalone}
\usepackage{filecontents}
\begin{filecontents*}{inimigo.dat}
x y label
52 10 a0
3 41 a1
51 52 a2
22 62 a3
36 32 a4
\end{filecontents*}
\begin{filecontents*}{pontofixo.dat}
x y label
115 45 Goal
\end{filecontents*}
\begin{filecontents*}{inicial.dat}
x y label
65  26  i0
47  37  i1
6   16  i2
44  5   i3
58  6   i4
\end{filecontents*}
\usepackage{caption}
\usepackage{subcaption}
\usepackage{pgfplots}
\pgfplotsset{compat=newest}
\usepackage{geometry}
\geometry{
 paperwidth=25cm,
 left=1in,right=1in,top=1in,bottom=1in
}
\begin{document}
\begin{figure}[h]
\centering
\begin{subfigure}{.4\textwidth}
  \centering
  \begin{tikzpicture}
  \begin{axis}[xmin=0,xmax=120,ymin=0,ymax=90, xstep=1,ystep=1,nodes near coords,enlargelimits=0.0]

\xdef\DoLater{}

     \addplot +[only marks,mark=*,nodes near
     coords={\makebox[0pt]{\coordinate(\labelz) at (\myx,\myy);}\labelz}, 
     visualization depends on={value \thisrowno{2}\as\labelz},
     visualization depends on={value \thisrow{x}\as\myx},
     visualization depends on={value \thisrow{y}\as\myy}] 
               table{pontofixo.dat}; % this defines the coordinate (Goal)
               % if I do not define it, the next sequence will throw an error
    \addplot +[scatter/position=relative,only marks,mark=*,
    nodes near coords={\labelz\makebox[0pt]{\coordinate(\labelz) at
    (\myx,\myy);
    \xdef\DoLater{\DoLater,\labelz}
    }}, visualization depends on={value \thisrowno{2}\as\labelz},
     visualization depends on={value \thisrow{x}\as\myx},
     visualization depends on={value \thisrow{y}\as\myy}] 
                table{inimigo.dat};

    \addplot +[scatter/position=relative,only marks,mark=*,
    nodes near coords={\labelz\makebox[0pt]{\coordinate(\labelz) at
    (\myx,\myy);
    \xdef\DoLater{\DoLater,\labelz}
    }}, visualization depends on={value \thisrowno{2}\as\labelz},
     visualization depends on={value \thisrow{x}\as\myx},
     visualization depends on={value \thisrow{y}\as\myy}] 
                table{inicial.dat};


  \end{axis}
  \foreach \Point in \DoLater{
\ifx\Point\empty%
\relax
\else
\draw (\Point) -- (Goal);
\fi
}
  \end{tikzpicture}
\caption{Estado inicial}
\end{subfigure}%
\centering
\begin{subfigure}{.4\textwidth}
  \centering
  \begin{tikzpicture}
  \begin{axis}[xmin=0,xmax=120,ymin=0,ymax=90, xstep=1,ystep=1,nodes near coords,enlargelimits=0.0]


\xdef\DoLater{}

     \addplot +[only marks,mark=*,nodes near
     coords={\makebox[0pt]{\coordinate(\labelz) at (\myx,\myy);}\labelz}, 
     visualization depends on={value \thisrowno{2}\as\labelz},
     visualization depends on={value \thisrow{x}\as\myx},
     visualization depends on={value \thisrow{y}\as\myy}] 
               table{pontofixo.dat}; % this defines the coordinate (Goal)
               % if I do not define it, the next sequence will throw an error
    \addplot +[scatter/position=relative,only marks,mark=*,
    nodes near coords={\labelz\makebox[0pt]{\coordinate(\labelz) at
    (\myx,\myy);
    \xdef\DoLater{\DoLater,\labelz}
    }}, visualization depends on={value \thisrowno{2}\as\labelz},
     visualization depends on={value \thisrow{x}\as\myx},
     visualization depends on={value \thisrow{y}\as\myy}] 
                table{inimigo.dat};

    \addplot +[scatter/position=relative,only marks,mark=*,
    nodes near coords={\labelz\makebox[0pt]{\coordinate(\labelz) at
    (\myx,\myy);
    \xdef\DoLater{\DoLater,\labelz}
    }}, visualization depends on={value \thisrowno{2}\as\labelz},
     visualization depends on={value \thisrow{x}\as\myx},
     visualization depends on={value \thisrow{y}\as\myy}] 
                table{gbest.dat};

  \end{axis}
  \foreach \Point in \DoLater{
\ifx\Point\empty%
\relax
\else
\draw (\Point) -- (Goal);
\fi
}
  \end{tikzpicture}
  \caption{Estado final}
\end{subfigure}%
\end{figure}
\end{document}

Explanation: While the tables are parsed, coordinates are defined which have the label ... have a guess ... label, and the coordinates are also stored in a list \DoLater. This list is parsed outside the axis environment (because of the delayed expansion issue) and then the connections are drawn. (Note that this version relies on the coordinate labels being unique, yet it is straightforward to add something like \coordindex to the label to make the labels unique in future applications of this trick.)

Answer 2

The main idea of this solution to give the nodes near coords a name so they can later be used/referenced to draw the connecting lines. After done that it only needs to be known

• how many \addplots where plotted and
• how many coordinates there are in each \addplot.

With this knowledge it is easy then to drawn the lines to "Goal".

(I only present the solution for the first graph, which then can easily be adopted to the second graph.)

For details please have a look at the comments in the code.

% used PGFPlots v1.15
    \begin{filecontents*}{pontofixo.dat}
        x   y   label
        115 45  Goal
    \end{filecontents*}
    \begin{filecontents*}{inimigo.dat}
        x   y   label
        52  10  a0
        3   41  a1
        51  52  a2
        22  62  a3
        36  32  a4
    \end{filecontents*}
    \begin{filecontents*}{inicial.dat}
        x   y   label
        65  26  i0
        47  37  i1
        6   16  i2
        44  5   i3
        58  6   i4
    \end{filecontents*}
\documentclass[border=5pt]{standalone}
\usepackage{pgfplotstable}
\usepackage{pgfplots}
\begin{document}
\begin{tikzpicture}
    \begin{axis}[
        xmin=0,
        xmax=120,
        ymin=0,
        ymax=90,
        enlargelimits=false,
        % moved common options here
        only marks,
        nodes near coords={\labelz},
        % give any "node near coord" a name
        nodes near coords style={
            name=a\plotnum-\coordindex,
        },
        visualization depends on={
            value \thisrowno{2}\as\labelz
        },
        % create a cycle list so there is no need for `\addplot' options
        cycle multiindex* list={
            color\nextlist
            mark=*\nextlist
        },
    ]
        \addplot table {pontofixo.dat};
        \addplot table {inimigo.dat};
        \addplot table {inicial.dat};

            % store the number of plots which will be needed outside the
            % `axis' environment
            \pgfmathtruncatemacro{\NumPlots}{\numplots}

    \end{axis}

    % now draw the lines
    \foreach \tab [count=\plotnumber from 1] in {
        inimigo.dat,
        inicial.dat%
    } {
            % get the number of rows per table so we know how many lines need to
            % be drawn per table
            \pgfplotstablegetrowsof{\tab}
            \pgfmathtruncatemacro{\NoOfRows}{\pgfplotsretval-1}
        \foreach \i in {0,...,\NoOfRows} {
            \draw (a\plotnumber-\i.south) -- (a0-0.south);
        }
    }
\end{tikzpicture}
\end{document}