[Tex/LaTex] draw half line between two nodes tikz

tikz-arrowstikz-pgf

I have the following graph:

\documentclass[border=1mm]{standalone}
\usepackage{siunitx}
\usepackage{tikz}

\begin{document}

\begin{tikzpicture}
]
  \node (n1) at (0,0)  [draw=black,auto=left,circle,thick,fill=red!50,scale=1.3] {$\mathbf{X}_1$};
  \node (n2) at (2,2)  [draw=black,auto=left,circle,thick,fill=red!50,scale=1.3] {$\mathbf{X}_2$};
  \node (n3) at (4,4)  [draw=black,auto=left,circle,thick,fill=red!50,scale=1.3] {$\mathbf{X}_3$};  

  \node (n4) at (3,0)  [draw=black,auto=left,circle,thick,fill=red!50,scale=1.3] {$\mathbf{X}_4$};
  \node (n5) at (5,2)  [draw=black,auto=left,circle,thick,fill=red!50,scale=1.3] {$\mathbf{X}_5$};
  \node (n6) at (7,4)  [draw=black,auto=left,circle,thick,fill=red!50,scale=1.3] {$\mathbf{X}_6$};  

  \node (n7) at (6,0)  [draw=black,auto=left,circle,thick,fill=red!50,scale=1.3] {$\mathbf{X}_7$};
  \node (n8) at (8,2)  [draw=black,auto=left,circle,thick,fill=red!50,scale=1.3] {$\mathbf{X}_8$};
  \node (n9) at (10,4) [draw=black,auto=left,circle,thick,fill=red!50,scale=1.3] {$\mathbf{X}_9$}; 

  \node (n11) at (0,5)  [draw=black,auto=left,circle,thick,fill=green!50,scale=1.2] {$\mathbf{Y}_{10}$};
  \node (n22) at (2,7)  [draw=black,auto=left,circle,thick,fill=green!50,scale=1.2] {$\mathbf{Y}_{11}$};
  \node (n33) at (4,9)  [draw=black,auto=left,circle,thick,fill=green!50,scale=1.2] {$\mathbf{Y}_{12}$};

  \node (n44) at (3,5)  [draw=black,auto=left,circle,thick,fill=green!50,scale=1.2] {$\mathbf{Y}_{13}$};
  \node (n55) at (5,7)  [draw=black,auto=left,circle,thick,fill=green!50,scale=1.2] {$\mathbf{Y}_{14}$};
  \node (n66) at (7,9)  [draw=black,auto=left,circle,thick,fill=green!50,scale=1.2] {$\mathbf{Y}_{15}$}; 

  \node (n77) at (6,5)  [draw=black,auto=left,circle,thick,fill=green!50,scale=1.2] {$\mathbf{Y}_{16}$};
  \node (n88) at (8,7)  [draw=black,auto=left,circle,thick,fill=green!50,scale=1.2] {$\mathbf{Y}_{17}$};
  \node (n99) at (10,9) [draw=black,auto=left,circle,thick,fill=green!50,scale=1.2] {$\mathbf{Y}_{18}$};  

  \node (n7h) at (9,0)  [] {$ $};
  \node (n8h) at (11,2) [] {$ $};
  \node (n9h) at (13,4) [] {$ $}; 

  \node (n1l) at (-3,0) [] {$ $};
  \node (n2l) at (-1,2) [] {$ $};
  \node (n3l) at (1,4)  [] {$ $};  

  \node (n1f) at (-2,-2) [] {$ $};
  \node (n4f) at (1,-2)  [] {$ $};
  \node (n7f) at (4,-2)  [] {$ $};  

  \node (n3t) at (6,6)  [] {$ $};
  \node (n6t) at (9,6)  [] {$ $};\draw ($(n1)!1cm!(n1l)$) -- ($(n1)!3cm!(n1l)$);
  \node (n9t) at (12,6) [] {$ $};

  \foreach \from/\to in {n11/n1,n22/n2,n33/n3,n44/n4,n55/n5,n66/n6,n77/n7,n88/n8,n99/n9}[ultra thin] \draw (\from) -- (\to);        
  \foreach \from/\to in {n1/n2,n2/n3,n4/n5,n5/n6,n7/n8,n8/n9} \draw[ultra thick] (\from) -- (\to);            
  \foreach \from/\to in {n1/n4,n4/n7,n2/n5,n5/n8,n3/n6,n6/n9} \draw[ultra thick] (\from) -- (\to);    
  \foreach \from/\to in {n7/n7h,n8/n8h,n9/n9h} \draw (\from)[dashed] -- (\to);     
  \foreach \from/\to in {n1/n1l,n2/n2l,n3/n3l} \draw (\from)[dashed] -- (\to); 
  \foreach \from/\to in {n1/n1f,n4/n4f,n7/n7f} \draw (\from)[dashed] -- (\to);  
  \foreach \from/\to in {n3/n3t,n6/n6t,n9/n9t} \draw (\from)[dashed] -- (\to);   
\end{tikzpicture}

\end{document}

I would like to draw a half dash line, for example between nodes X_1 and Y_{13}. How can I do this?

Best Answer

Another interpretation of "half dashed":

\documentclass[tikz,border=5]{standalone}
\usetikzlibrary{decorations.pathreplacing,calc}
\tikzset{draw half paths/.style 2 args={%
  decoration={show path construction,
    lineto code={
      \draw [#1] (\tikzinputsegmentfirst) -- 
         ($(\tikzinputsegmentfirst)!0.5!(\tikzinputsegmentlast)$);
      \draw [#2] ($(\tikzinputsegmentfirst)!0.5!(\tikzinputsegmentlast)$)
        -- (\tikzinputsegmentlast);
    }
  }, decorate
}}
\begin{document}
\begin{tikzpicture}[every node/.style={circle, draw}, >=stealth]
\foreach \i in {1,...,5}
  \node (n-\i) at (72*\i:2) {\i};

\path [draw half paths={solid}{dashed}]  (n-1) -- (n-3);
\path [draw half paths={dotted}{dashed}] (n-2) -- (n-4);
\path [draw half paths={blue, thin}{red, very thick}] (n-3) -- (n-5);
\path [draw half paths={dashed}{draw=none}] (n-4) -- (n-1);
\path [draw half paths={dotted, ->}{draw=none}] (n-5) -- (n-2);
\end{tikzpicture}
\end{document}

Related Solutions

[Tex/LaTex] How to draw points in TikZ

Method I (using node)

\tikzset{
  every point/.style = {circle, inner sep={.75\pgflinewidth}, opacity=1, draw, solid, fill=white},
  point/.style={insert path={node[every point, #1]{}}}, point/.default={},
  point name/.style = {insert path={coordinate (#1)}},
}

and some extra stuff :

\tikzset{
  colored point/.style = {point={fill=#1}},
  inherit/.style = {point/.style={insert path={node[circle, inner sep={.75\pgflinewidth}, draw, fill, #1]{}}}}
}

Satisfies 1.
Satisfies 2 with styling like this [point={fill=red, very thick}]
Partially satisfies 3. I don't know how to define draw opacity=inherit or fill=inherit. I define new style inherit which will redefine the entire point by removing the opacity=1 and fill=white, but this is ugly ;).
Partially satisfy 4 : you can use point name=A. I would like to be able to use quotes for saying something like [point={red, "A"}] but I don't know how to do this.
Almost satisfy 5 : we can put [point] almost anywhere, like (A) [point], or node[point, above]{A}, or coordinate[point](A). But can't be used with \coordinate at or \node at (except if you repeat yourself like this \coordinate (A) at (1,1) (A) [point];)
FAILS on 6. I know that there is a hacky solution to put node on layer, but this is in contradiction with 7).
Satisfies 7.

The full code of all tests and the result

\documentclass[varwidth,border=50]{standalone}
\usepackage{tikz}

% not clear how to use layers with this method
\pgfdeclarelayer{background}
\pgfdeclarelayer{foreground}
\pgfsetlayers{background,main,foreground}

\tikzset{
  every point/.style = {circle, inner sep={.75\pgflinewidth}, opacity=1, draw, solid, fill=white},
  point/.style={insert path={node[every point, #1]{}}}, point/.default={},
  colored point/.style = {point={fill=#1}},
  point name/.style = {insert path={coordinate (#1)}},
  inherit/.style = {point/.style={insert path={node[circle, inner sep={.75\pgflinewidth}, draw, fill, #1]{}}}}
}

\begin{document}
  \begin{itemize}

    % ---------------------------------
    \item Test 1 : ok.\\[1em]
    \begin{tikzpicture}
      \foreach[count=\i] \w in {ultra thin, thin, ultra thick} {
      \draw[yshift=-\i em, \w] (0,0) -- (.5,0) [point] -- (1,0);
      }
      \foreach[count=\i] \s in {.2, .5, 1} {
      \draw[xshift=1.5cm, yshift=-\i em, scale=\s] (0,0) -- (.5,0) [point] -- (1,0);
      }
    \end{tikzpicture}

    % ---------------------------------
    \item Test 2 : ok.

    % ---------------------------------
    \item Test 3 : partialy ok, there is no good \texttt{inherit}.\\
    \begin{tikzpicture}[scale=2, very thick]
      \filldraw[draw opacity=.5, draw=red, fill opacity=.3, densely dotted]
        (0,0) [point] -- (.5,0) [point={ultra thick, fill=green}] -- (.5,.5) [inherit, point] -- cycle;
    \end{tikzpicture}

    % ---------------------------------
    \item Test 4 : almost ok (using \texttt{point name})\\
    \begin{tikzpicture}
      \draw[very thick] (0,1) [point] -- (1,0) [point={thick, fill=green, point name=A}];
      \draw[ultra thick, purple] (0,0) [point] -- (A);
    \end{tikzpicture}

    % ---------------------------------
    \item Test 5 : almost ok.

    % ---------------------------------
    \item Test 6 : fails ! (visible in test 4 too)\\
    \begin{tikzpicture}
      \coordinate (A) at (0,1) (A) node[point=ultra thick, left] {A};
      \coordinate (B) at (1,0) (B) [thick, point];
      \draw (A) -- (B);
    \end{tikzpicture}

  \end{itemize}
\end{document}

enter image description here

Method II (using pic)

\pgfdeclarelayer{background}
\pgfdeclarelayer{foreground}
\pgfsetlayers{background,main,foreground}

\tikzset{
  every point/.style = {radius={\pgflinewidth}, opacity=1, draw, solid, fill=white},
  pt/.pic = {
    \begin{pgfonlayer}{foreground}
      \path[every point, #1] circle;
    \end{pgfonlayer}
  },
  point/.style={insert path={pic{pt={#1}}}}, point/.default={},
  point name/.style = {insert path={coordinate (#1)}}
}

FAILS on 1. I don't know how to inherit styles from path to pic. Is there some style like current path style ?
Satisfies 2. Same as method I.
FAILS on 3. We can style as in method I, but because (1) fails, (3) fails.
Partially satisfies 4. Same as method I.
FAILS on 5 : as there is a bug in 'pic' we can't use node after it in PGF 3.0. When this bug will be fixed, this method will be equivalent to the first one at this test.
Satisfies 6. This is the main interest of this method.
Satisfies 7.

The full code of all tests and the result

\documentclass[varwidth,border=50]{standalone}
\usepackage{tikz}

\pgfdeclarelayer{background}
\pgfdeclarelayer{foreground}
\pgfsetlayers{background,main,foreground}

\tikzset{
  every point/.style = {radius={\pgflinewidth}, opacity=1, draw, solid, fill=white},
  pt/.pic = {
    \begin{pgfonlayer}{foreground}
      \path[every point, #1] circle;
    \end{pgfonlayer}
  },
  point/.style={insert path={pic{pt={#1}}}}, point/.default={},
  colored point/.style = {point={fill=#1}},
  point name/.style = {insert path={coordinate (#1)}}
}

\begin{document}
\begin{itemize}
\item Test 1 : fails for sizing from path width, scale is ok.\\[1em]
\begin{tikzpicture}
  \foreach[count=\i] \w in {ultra thin, thin, ultra thick} {
  \draw[yshift=-\i em, \w] (0,0) -- (.5,0) [point] -- (1,0);
  }
  \foreach[count=\i] \s in {.2, .5, 1} {
  \draw[xshift=1.5cm, yshift=-\i em, scale=\s] (0,0) -- (.5,0) [point] -- (1,0);
  }
\end{tikzpicture}

\item Test 2 : partialy ok, there is no \texttt{inherit} (at all).

\item Test 3 : fails ! Can't inherit style from path.\\
\begin{tikzpicture}[scale=2, very thick, densely dotted]
  \filldraw[draw opacity=.5, draw=red, fill opacity=.3]
    (0,0) [point] -- (.5,0) [point={ultra thick, fill=green}] -- (.5,.5) [point] -- cycle;
\end{tikzpicture}

\item Test 4 : almost ok (using \texttt{point name})\\
\begin{tikzpicture}
  \draw[very thick] (0,1) [point] -- (1,0) [point={thick, fill=green, point name=A}];
  \draw[ultra thick, purple] (0,0) [point] -- (A);
\end{tikzpicture}

\item Test 5 : fails ! (can't put node after [point] )

\item Test 6 : ok.\\
\begin{tikzpicture}
  \path (0,1) node[left] {A} coordinate (A) [point=ultra thick];
  \coordinate (B) at (1,0) (B) [thick, point];
  \draw (A) -- (B);
\end{tikzpicture}
\end{itemize}
\end{document}

enter image description here

[Tex/LaTex] TikZ: Drawing an arc from an intersection to an intersection

A solution which allows to draw intersection segments of any two intersections is available as tikz library fillbetween.

This library works as general purpose tikz library, but it is shipped with pgfplots and you need to load pgfplots in order to make it work:

\documentclass{standalone}

\usepackage{tikz}
\usepackage{pgfplots}
\usetikzlibrary{fillbetween}

\begin{document}

\begin{tikzpicture}

\draw [name path=red,red] (120:1.06) circle (1.9);
%\draw [name path=yellow,yellow] (0:1.06) circle (2.12);
\draw [name path=green,green!50!black] (0:0.77) circle (2.41);
\draw [name path=blue,blue] (0:0) circle (1.06);

% substitute this temp path by `\path` to make it invisible:
\draw[name path=temp1, intersection segments={of=red and blue,sequence=L1}];
\draw[red,-stealth,ultra thick, intersection segments={of=temp1 and green,sequence=L3}];

\end{tikzpicture}

\end{document}

enter image description here

The key intersection segments is described in all detail in the pgfplots reference manual section "5.6.6 Intersection Segment Recombination"; the key idea in this case is to

create a temporary path temp1 which is the first intersection segment of red and blue, more precisely, it is the first intersection segment in the Left argument in red and blue : red. This path is drawn as thin black path. Substitute its \draw statement by \path to make it invisible.
Compute the desired intersection segment by intersecting temp1 and green and use the correct intersection segment. By trial and error I figured that it is the third segment of path temp1 which is written as L3 (L = left argument in temp1 and green and 3 means third segment of that path).

The argument involves some trial and error because fillbetween is unaware of the fact that end and startpoint are connected -- and we as end users do not see start and end point.

Note that you can connect these path segments with other paths. If such an intersection segment should be the continuation of another path, use -- as before the first argument in sequence. This allows to fill paths segments:

\documentclass{standalone}

\usepackage{tikz}
\usepackage{pgfplots}
\usetikzlibrary{fillbetween}

\begin{document}

\begin{tikzpicture}

\draw [name path=red,red] (120:1.06) circle (1.9);
%\draw [name path=yellow,yellow] (0:1.06) circle (2.12);
\draw [name path=green,green!50!black] (0:0.77) circle (2.41);
\draw [name path=blue,blue] (0:0) circle (1.06);

% substitute this temp path by `\path` to make it invisible:
\draw[name path=temp1, intersection segments={of=red and blue,sequence=L1}];
\draw[red,fill=blue,-stealth,ultra thick, intersection segments={of=temp1 and green,sequence=L3}]  
    [intersection segments={of=temp1 and green, sequence={--R2}}]
;

\end{tikzpicture}

\end{document}

enter image description here

Best Answer

Related Solutions

[Tex/LaTex] How to draw points in TikZ

[Tex/LaTex] TikZ: Drawing an arc from an intersection to an intersection

Related Question