[Tex/LaTex] Circles at the ends of arrows

arrows

Consider four kinds of "arrow" symbols: 0. A horizontal line 1. A leftarrow 2. A rightarrow 3. A doublearrow

I'd like to add circles to each end of these arrows, allowing for all possible combinations of "filled" and "unfilled," for a total of sixteen combinations in total. As an example, one may consider the "spoons" offered by the MnSymbol package for reference, as in \leftspoon and \leftfilledspoon.

Any ideas as to how to achieve this?

EDIT: So to clarify, I want circles on BOTH ends of the arrows. As in O–>O.

Best Answer

You can use \hbox to create your own arrows by appending other symbols, like this:

\def\CircleftarrowCirc{\hbox{$\circ$}\kern-1.5pt\hbox{$\leftarrow$}\kern 1.5pt\hbox{$\circ$}}

enter image description here

Related Solutions

[Tex/LaTex] Rounded ends with tikz

You can use the line cap=round option (other permissible values are butt (default) and rect):

\documentclass{article}
\usepackage{tikz}

\begin{document}
\begin{tikzpicture}
    \draw[double distance = 0.5cm,line cap=round] (0,0) -- (1,0);
\end{tikzpicture}
\end{document}

result

Note however that the cap extends beyond the actual line (i.e. (0,0) is at the center of the cap and not on the boundary).

Here is an actual arrow tip:

\documentclass{article}
\usepackage{tikz}

\makeatletter
\pgfarrowsdeclare{open cap}{open cap}
{\pgfarrowsleftextend{+0pt}\pgfarrowsrightextend{+0.5\pgflinewidth}}
{
  \pgfmathsetlength{\pgfutil@tempdimb}{.5*\pgflinewidth-.5*\pgfinnerlinewidth}%
  \pgfsetlinewidth{\pgfutil@tempdimb}
  \pgfsetbuttcap
  \pgfsetdash{}{0pt}
  \pgfmathsetlength{\pgfutil@tempdima}{.5*\pgfutil@tempdimb+.5*\pgfinnerlinewidth}%
  \pgfpathmoveto{\pgfqpoint{0pt}{\pgfutil@tempdima}}
  \pgfpatharc{270}{90}{-\pgfutil@tempdima}
  \pgfusepathqstroke
}
\makeatother

\begin{document}
\begin{tikzpicture}
    \draw[very thick,double distance = 0.5cm,open cap-open cap] (0,0) -- (1,0);
\end{tikzpicture}
\end{document}

result

Here (0,0) is at the end of the line (i.e. the boundary of the cap).

[Tex/LaTex] Adding symbols at the end(s) of a horizontal line

One can use TikZ; this is a prototype with a perhaps convenient syntax where the argument to \erelbar consists of two digits (0, 1, 2, or 3):

0 stands for no arrowhead
1 stands for a normal arrowhead
2 stands for a bar
3 stands for both bar and arrowhead

The first digit refers to the left side, the second one to the right side.

\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{arrows}

\makeatletter
\newcommand\@erelb@r[1]{%
  \mathrel{\tikz[baseline=-.5ex]\draw[#1] (0,0)--(0.3,0);}
}
% 0 is for nothing
% 1 is for arrowhead
% 2 is for bar
% 3 is for both
\newcommand{\erelbar}[1]{\@erelbar#1}
\def\@erelbar#1#2{%
  \ifcase\numexpr#1*4+#2\relax
    \@erelb@r{-}\or     % 00
    \@erelb@r{->}\or    % 01
    \@erelb@r{-|}\or    % 02
    \@erelb@r{->|}\or   % 03
    \@erelb@r{<-}\or    % 10
    \@erelb@r{<->}\or   % 11
    \@erelb@r{<-|}\or   % 12
    \@erelb@r{<->}\or   % 13
    \@erelb@r{|-}\or    % 20
    \@erelb@r{|->}\or   % 21
    \@erelb@r{|-|}\or   % 22
    \@erelb@r{|<->|}\or % 23
    \@erelb@r{|<-}\or   % 30
    \@erelb@r{|<->}\or  % 31
    \@erelb@r{|<-|}\or  % 32
    \@erelb@r{|<->|}    % 33
  \else
    \@wrong
  \fi
}
\makeatother
\begin{document}

$a\erelbar{11}b$

$\begin{array}{cccc}
\erelbar{00} & \erelbar{10} & \erelbar{20} & \erelbar{30} \\
\erelbar{01} & \erelbar{11} & \erelbar{21} & \erelbar{31} \\
\erelbar{02} & \erelbar{12} & \erelbar{22} & \erelbar{32} \\
\erelbar{03} & \erelbar{13} & \erelbar{23} & \erelbar{33} \\
\end{array}$
\end{document}

enter image description here

Best Answer

Related Solutions

[Tex/LaTex] Rounded ends with tikz

[Tex/LaTex] Adding symbols at the end(s) of a horizontal line

Related Question