[Tex/LaTex] Draw dimension of a line as a decoration in TikZ

dimensionslabelstechnical-drawingtikz-pgf

Is it possible to define in TikZ a new decoration or something like that, such that it is possible to write something like:

\draw[dim={text,above}] (A) -- (B);
\draw[dim={text,below}] (C) -- (D);

or even better

\draw (A) dim[text,above] (B);
\draw (C) dim[text,below] (C);

to get something like this:

dim

It's important that the text is sloped.

If possible I would prefer the second syntax, because then I could easily combine such path's:

\draw (A) dim[text,above] (B) -- (C) -- (D) dim[text] (E) dim[text,below] (F) -- circle;

Best Answer

Update

The result looks fine but perhaps the code can be improved.

\documentclass{standalone}
\usepackage{tikz}
\usetikzlibrary{decorations,decorations.markings,decorations.text}

\begin{document}
 \pgfkeys{/pgf/decoration/.cd,
      distance/.initial=10pt
}  

\pgfdeclaredecoration{add dim}{final}{
\state{final}{% 
\pgfmathsetmacro{\dist}{5pt*\pgfkeysvalueof{/pgf/decoration/distance}/abs(\pgfkeysvalueof{/pgf/decoration/distance})} 
          \pgfpathmoveto{\pgfpoint{0pt}{0pt}}             
          \pgfpathlineto{\pgfpoint{0pt}{2*\dist}}   
          \pgfpathmoveto{\pgfpoint{\pgfdecoratedpathlength}{0pt}} 
          \pgfpathlineto{\pgfpoint{(\pgfdecoratedpathlength}{2*\dist}}
           \pgfusepath{stroke} 
          \pgfsetdash{{0.1cm}{0.1cm}{0.1cm}{0.1cm}}{0cm}     
          \pgfsetarrowsstart{latex}
          \pgfsetarrowsend{latex}  
          \pgfpathmoveto{\pgfpoint{0pt}{\dist}}
          \pgfpathlineto{\pgfpoint{\pgfdecoratedpathlength}{\dist}} 
          \pgfusepath{stroke} 
          \pgfsetdash{}{0pt}
          \pgfpathmoveto{\pgfpoint{0pt}{0pt}}
          \pgfpathlineto{\pgfpoint{\pgfdecoratedpathlength}{0pt}}
}}

\tikzset{dim/.style args={#1,#2}{decoration={add dim,distance=#2},
                decorate,
                postaction={decorate,decoration={text along path,
                                                 raise=#2,
                                                 text align={align=center},
                                                 text={#1}}}}}

\begin{tikzpicture}
\coordinate (A) at (0,0);
\coordinate (B) at (4,2);
\coordinate (C) at (8,-2);

\draw[dim={5 cm,10pt,}]  (A) --  (B);
\draw[dim={7 cm,-15pt}]  (B) --  (C); 

\draw[fill=gray] (A) circle(2pt); 
\draw[fill=gray] (B) circle(2pt);
\draw[fill=gray] (C) circle(2pt);   
\end{tikzpicture}

\end{document}

Update : possible with edge

\draw (A) edge [dim={5 cm,10pt}]  (B) 
          edge[dim={7 cm,-15pt}]  (C)
       (B)edge[dim={4 cm,+10pt}]  (C);

enter image description here

Related Solutions

[Tex/LaTex] Draw crosses in tikz

cross command equivalent to circle doesn't exist in TiKZ but you can use a cross out node from shapes.misc library. This kind of node adds a cross over node's text, but it's easy to adapt it to do what you want.

\tikzset{cross/.style={cross out, draw, 
         minimum size=2*(#1-\pgflinewidth), 
         inner sep=0pt, outer sep=0pt}}

Because circle (1pt) draws a circle with radius=1pt, its total size will be 2pt, then cross node's size is defined with minimum size=2*(#1-\pgflinewidth) and inner and outer separations fixed to 0pt.

If cross angle is not what you want, you can change it with rotate option. Next you have some examples. I've also placed circles over them just to show that circle and crosses have equal size.

\documentclass[tikz, border=2mm]{standalone}
\usetikzlibrary{shapes.misc}

\tikzset{cross/.style={cross out, draw=black, minimum size=2*(#1-\pgflinewidth), inner sep=0pt, outer sep=0pt},
%default radius will be 1pt. 
cross/.default={1pt}}

\begin{document}
\begin{tikzpicture}[]

\draw (0,0) circle (1pt);

\draw (.5,0) node[cross,rotate=10] {};
\draw (.5,0) circle (1pt);

\draw (0,.5) circle (1pt);
\draw (0,.5) node[cross,red] {};

\draw (.5,.5) node[cross,rotate=30] {};

\draw (0.25,.25) circle (2pt);
\draw (0.25,.25) node[cross=2pt,rotate=45,green]{};
\end{tikzpicture}
\end{document}

enter image description here

[Tex/LaTex] Tikz: draw a circle only in selected nodes

Previous note: Please, next time provide a COMPLETE minimal working (or not) example: starting from \documentclass... and finishing with \end{document} with all libraries and personal functions you use to test your code.

Answer: I'm not sure about what you want to do but if you just want to add some filled circles to previous defined nodes you can do it outside the foreach loop. Node names are known after foreach so you can make reference to them. There's no need for if inside the loop to add color to a particular node. If you don't know the particular name or want to calculate it forget my answer.

If you draw a filled circle at a node center you'll cover its contents, but you can use backgrounds library to add the filled circle behind the node. Both examples are shown in next code.

Final note: I've suposed that \hashcell was related to your previous question Tikz: define label font size under the node

\documentclass[tikz,border=2mm]{standalone}

\usetikzlibrary{backgrounds}
\tikzset{
  cell/.style = {draw, minimum width=0.5cm, minimum height=0.5cm, minimum size = 0.5cm}
}


\begin{document}

\begin{tikzpicture}

\foreach [count=\i from 0] \j  in {1,...,7} {
    \node[cell,label=below:{\scriptsize \i}] (cell\i) at (\i*0.5,0) {};}

\foreach [count=\i from 0] \number in {0, 0, 1, 0, 1, 0, 0}{
              \node at (cell\i) {\number};
              }

               \draw [fill=yellow] (0,0) circle (0.2cm) node (sun) {};

    \begin{scope}[on background layer] 
              \draw [fill=yellow] (cell2.center) circle (0.2cm) node (sun) {};
    \end{scope}

\end{tikzpicture}
\end{document}

enter image description here

Best Answer

Related Solutions

[Tex/LaTex] Draw crosses in tikz

[Tex/LaTex] Tikz: draw a circle only in selected nodes

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