[Tex/LaTex] Making a thicker \cdot for dot product (that is thinner than \bullet)

math-modesymbols

I'm trying to replicate the dot that my professor uses in his notes for the dot product between vectors but I am having a hard time doing so. This is what it looks like:

enter image description here

I have tried a couple of things. \cdot is too thin

asdf

and \bullet is too thick

enter image description here

and using \Large with \cdot gives an error. Moreover, after digging through the list of symbols I cannot find a nice medium between \cdot and \bullet.

How can I get a dot closest to the first picture?

Best Answer

May be you find a better name like \dotp or something like that.

\documentclass{scrartcl}
\usepackage{graphicx}

\makeatletter
\newcommand*\bigcdot{\mathpalette\bigcdot@{.5}}
\newcommand*\bigcdot@[2]{\mathbin{\vcenter{\hbox{\scalebox{#2}{$\m@th#1\bullet$}}}}}
\makeatother

\begin{document}
$a \bigcdot b$
\end{document}

enter image description here

Related Solutions

[Tex/LaTex] A comma decimal separator that is bigger than a dot

You need an intelligent comma-package like icomma or ncccomma.

You can also adapt the code from Claudio Beccari's article in The PracTEX Journal, 2011, No. 1.

Add

\usepackage{icomma}

\usepackage{ncccomma}

to your preamble.

If you have none of those packages installed, you can add Claudio Beccari's code to your preamble (I have removed the comments and added \makeatother as the last line):

\makeatletter
\DeclareMathSymbol{\punctcomma}{\mathpunct}{letters}{"3B}
\DeclareMathSymbol{\decimalcomma}{\mathord}{letters}{"3B}
\AtBeginDocument{\mathcode‘\,="8000}
{\catcode‘\,=\active \gdef,{\futurelet\let@token\m@thcomma}}
\def\m@thcomma{\let\@tempB\punctcomma
\@tfor\@tempA:=0123456789\do{%
    \expandafter\ifx\@tempA\let@token\let\@tempB\decimalcomma
    \@break@tfor\fi}\@tempB}
\makeatother

Hopefully, this will help.

[Tex/LaTex] To write dot product \cdot is not working

I have two suggestions:

Load the amsmath package and rewrite the equation as

\nabla \cdot \boldsymbol{\sigma} + \mathbf{f}^{\mathbf{b}}=0

Load the bm ("bold math") package and rewrite the equation as
```
\nabla \cdot \bm{\sigma} + \bm{f^b}=0
```

The former method will generate upright-bold letters "f" and "b"; the second will generate italic-bold letters "f" and "b". Your choice.

Note that the + symbol should (almost certainly) not be rendered in bold. For sure, \mathbf{\sigma} is not good; write either \boldsymbol{\sigma} or \bm{\sigma}.

\documentclass[applsci,article,submit,moreauthors,
               pdftex,10pt,a4paper]{mdpi} % see https://www.mdpi.com/authors/latex
\usepackage{amsmath} % for "\boldsymbol" macro
\usepackage{bm}      % for "\bm" macro

\makeatletter  % just to make the code minimally compilable
\let\@Title\relax
\let\@Author\relax
\let\@address\relax
\makeatother

\begin{document}

\begin{equation} \label{eq:boldsymb}
\nabla \cdot \boldsymbol{\sigma} + \mathbf{f}^{\mathbf{b}}=0
\end{equation}

\begin{equation} \label{eq:bm}
\nabla \cdot \bm{\sigma} + \bm{f^b}=0
\end{equation}

\end{document}