[Tex/LaTex] How to put bullet symbol on top of downarrow symbol

stacking-symbolssymbols

I want to put bullet symbol on top of downward arrow symbol. Can someone help me on this?

\documentclass{article}
\usepackage{graphicx}

\begin{document}

The transition is represented with $\mathrel{\bullet}\downarrow $ arrow.

\end{document}

Edit1: Actually I want to attach bullet symbol on top of downarrow symbol without any gap.

Best Answer

I don't really know what I'm doing with this, but a suggestion with \ooalign and \mathchoice:

enter image description here

\documentclass{article}
\newcommand\bulletarrow{%
\mathchoice
  {{\ooalign{\raise0.8ex\hbox{$\bullet$}\cr$\downarrow$}}}
  {{\ooalign{\raise0.8ex\hbox{$\bullet$}\cr$\downarrow$}}}
  {{\ooalign{\raise0.65ex\hbox{$\scriptstyle\bullet$}\cr$\scriptstyle\downarrow$}}}
  {{\ooalign{\raise0.5ex\hbox{$\scriptscriptstyle\bullet$}\cr$\scriptscriptstyle\downarrow$}}}%
}

\begin{document}

The transition is represented with $ \bulletarrow_{\bulletarrow_{\bulletarrow}} $ arrow.
\end{document}

For more information about \ooalign see egregs answer to another question.

Related Solutions

[Tex/LaTex] How to put symbol around the equal sign

The amsmath package provides the \overset and \underset macros that can be used to place one symbol above or below another. If you want text above and below, you could use \DeclareMathOperator* (also from amsmath).

\documentclass{minimal}
\usepackage{amsmath}
\DeclareMathOperator*{\eq}{=}
\begin{document}
\begin{equation*}
\underset{b}{=} \quad  \eq^a_b
\end{equation*}
\end{document}

There shouldn't be any problems using this in amsmath environments such as align.

\begin{align*}
A  &\eq^b_a B \\
   &\eq^b_a C
\end{align*}

However, if you use it in the middle column of an eqnarray or eqnarray* (which are generally considered to be obsolete), then you will need \displaystyle before \eq.

All of the above applies to egreg's suggestion of defining \eq via

\newcommand{\eq}[2]{\mathrel{\operatorname*{=}_#1^#2}}

which seems to improve the spacing (and may be better in other ways as well).

[Tex/LaTex] How to put a symbol inside a circle arrow

Here is slightly automated solution using tikz. I measure the height and width of the text and place an arc whose size is based on the maximum of that. Am sure this can be improved, but this should get you started:

enter image description here

\documentclass{article}
\usepackage{amsmath}
\usepackage{tikz}
\usepackage{calc}

\makeatletter
\newlength\@SizeOfCirc%
\newcommand{\CricArrowRight}[1]{%
    \setlength{\@SizeOfCirc}{\maxof{\widthof{#1}}{\heightof{#1}}}%
    \tikz [x=1.0ex,y=1.0ex,line width=.15ex, draw=blue]%
        \draw [->,anchor=center]%
            node (0,0) {#1}%
            (0,1.2\@SizeOfCirc) arc (85:-240:1.2\@SizeOfCirc);%
}%
\makeatother

\begin{document}
\CricArrowRight{$i$}
\CricArrowRight{$i_3$}
\CricArrowRight{$\frac{a}{b}$}
\CricArrowRight{$\dfrac{a}{b}$}
\end{document}

I created a temporary length \@SizeOfCirc so as to minimize potential name conflicts, and need to use \maktatother. See What do \makeatletter and \makeatother do? for more info if you are not familiar with that.

Best Answer

Related Solutions

[Tex/LaTex] How to put symbol around the equal sign

[Tex/LaTex] How to put a symbol inside a circle arrow

Related Question