Dotted line with prescribed density with TikZ

Question

Is there a way to get a dotted line with prescribed density, for instance 10 dots per centimeter, instead of the default?

With Jesse's comment :

\documentclass[10pt,a4paper,french]{article}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{fourier}
\usepackage{tikz}
\usetikzlibrary{calc,intersections,through,backgrounds}

\tikzstyle{cm dotted}=[dash pattern=on \pgflinewidth off .85mm ]

\begin{document}
\begin{tikzpicture}

\draw[cm dotted,line width=.15mm,step=.5] (0,0) grid (5,4) ;

\end{tikzpicture}
\end{document}

Still an unwanted shift of half a linewidth. The horizontal and vertical crossing points are not on at the right place. I understand why, but I don't know how fix it.

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This could provide some directions -- http://tex.stackexchange.com/a/45276/34618 — Jesse, Feb 01 '14 at 12:32
@Jesse, it goes in the good direction. It works but still a unwanted shift of half a linewith. — Tarass, Feb 01 '14 at 13:14
You could update your question and give a more specific concerns, experts here are ready to help out. — Jesse, Feb 01 '14 at 13:33

score 15 · Accepted Answer · answered Feb 01 '14 at 13:45

15

I think this does it. The size of the dot is determined by the line width. The trick is to use a dash of length 0. Which I suppose shouldn't work, but seems to.

\documentclass[tikz,border=0.125cm]{standalone}

\tikzset{%
  dots/.style args={#1per #2}{%
    line cap=round,
    dash pattern=on 0 off #2/#1
  }
}

\begin{document}

\foreach \i in {1,...,20}{
  \begin{tikzpicture}
    \draw [help lines] grid (4,1);
    \draw [very thick, dots=\i per 1cm] 
      (0,.5) -- (4,.5) 
      node [at start, above right] {\i\ dot\ifnum\i>1s\fi\ per 1cm};
  \end{tikzpicture}
}

\end{document}

enter image description here

answered Feb 01 '14 at 13:45

Mark Wibrow

70,437

It works just fine, the grid is perfect. – Tarass Feb 01 '14 at 14:20
@MarkWibrow How do you make that animated image? (gif I assume). Is it easy to do? – Jonathan Komar Nov 17 '16 at 12:20
@macmadness86 open the PDF in gimp with pages as layers, reverse the layers (Layer->Stack->Reverse layer order) and then export to as a gif. It is also possible to optimise the animation (Filters>Animation->Optimise for GIF) – Mark Wibrow Nov 18 '16 at 14:03

kiss my armpit · Answer 2 · 2014-02-01T14:13:28.160

2

With dotsep in PSTricks.

\documentclass[pstricks,border=12pt]{standalone}
\usepackage{multido}
\psset{linewidth=1mm,linestyle=dotted}
\begin{document}
\begin{pspicture}(6,8)
\multido{\i=0+1,\n=.1+.1}{9}{\psline[dotsep=\n](0,\i)(6,\i)}
\end{pspicture}
\end{document}

enter image description here

Edit

\documentclass[pstricks,border=12pt]{standalone}
\psset{linewidth=3pt,linestyle=dotted}
\newlength\dotsep
\def\line#1{%
    \dotsep=\dimexpr\dimexpr\psunit-#1\pslinewidth\relax/\numexpr#1-1\relax\relax
    \psline[dotsep=\dotsep](0,1)(6,1)}

\begin{document}
    \foreach \i in {2,...,10}{%
    \begin{pspicture}[showgrid](6,2)
        \rput[t](3,1.75){\i\ dots per cm}   
        \line{\i}
    \end{pspicture}}
\end{document}

enter image description here

edited Feb 01 '14 at 14:13

answered Feb 01 '14 at 12:16

kiss my armpit

36,086

With pstricks I usualy use psgrid and it works find. I know how to do this with metapost. But now I need a tikz command (without foreach), but a style to apply on a line or on a grid. – Tarass Feb 01 '14 at 12:50
@Tarass: OK. The multido in my answer is trivial. – kiss my armpit Feb 01 '14 at 12:53
My question was not clear enought. – Tarass Feb 01 '14 at 13:46
Look carefully the difference with Mark Wibrow tikz solution: the first and the last points are not on the grid, it means that it isn't precise enought especialy to make a grid. Exactly the grid pstrciks does and you use for your example. With you solution, the vertical and horizontal lines don't match at crossing points. – Tarass Feb 02 '14 at 08:03

score 0 · Answer 3 · answered Feb 01 '14 at 12:30

The “old” plain TeX actually does this out of the box in one line, without the need of external complex packages:

my text\leaders\hbox to 1em{\hss.\hss}\hfill other text

Other options are:

use \hskip 5cm instead of \hfill to produce a dotted line 5cm long
use \hbox to 0.1cm instead of hbox to 1em to change the dot separation to 1mm
use \cleaders instead of \leaders to center the leaders, instead of having them alined
use \xleaders to have the leaders expanded to fill out the entire space (in this case the separation provided is a lower limit only).

I need a tikz style like dotted densely, but with a way to prescribe the number of points in a cm. — Tarass, Feb 01 '14 at 12:47

Dotted line with prescribed density with TikZ

3 Answers3

Edit

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