A comma decimal separator that is bigger than a dot

Question

\documentclass{mwrep}
\usepackage{amsmath}
\begin{document}
Check:\\
with "," $0,125$\\
with "." $0.125$

with commas:
\begin{equation}
P=
\begin{bmatrix} 0,1 & 0,3 & 0,0 & 0,6 \\
                0,2 & 0,4 & 0,1 & 0,3 \\
                0,0 & 0,8 & 0,0 & 0,2 \\
                0,2 & 0,0 & 0,2 & 0,6
\end{bmatrix}
\end{equation}

with dots:
\begin{equation}
P=
\begin{bmatrix} 0.1 & 0.3 & 0.0 & 0.6 \\
                0.2 & 0.4 & 0.1 & 0.3 \\
                0.0 & 0.8 & 0.0 & 0.2 \\
                0.2 & 0.0 & 0.2 & 0.6
\end{bmatrix}
\end{equation}

\end{document}

As you can see numbers with a comma as a decimal separator are wider than those with a dot. How can I change space after a comma to be equal to space after a dot?

See also German language: use of comma in numbers. – Hendrik Vogt Jun 20 '12 at 07:21 — Hendrik Vogt, Jun 20 '12 at 07:21

Sveinung · Accepted Answer · 2015-02-05T09:59:03.107

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}

or

\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.

wipet · Answer 2 · 2015-02-05T12:54:27.370

2

I don't know what intelligence is hidden in the mentioned intelligent packages, but I guess that it can be implemented by the four lines:

\def\mathcomma{\futurelet\next\mathcommaA}
\def\mathcommaA{\mathchar`, \expandafter\ifx\space\next\,\fi}
{\catcode`,=13 \global\let,=\mathcomma}
\mathcode`,="8000

without space after comma: $1,234$ with spaces: $1, 2, 3$.

\bye

edited Feb 05 '15 at 12:54

answered Feb 05 '15 at 12:44

wipet

74,238

This is essentially the same as the code in icomma.sty. – egreg Feb 05 '15 at 13:14
The icomma.sty uses sequences \ProvidesPackage, \AtBeginDocument and many @ like sequences. This makes the macro file format dependent. My macro is format independent (as usual). This is substantial difference. – wipet Feb 05 '15 at 15:50

A comma decimal separator that is bigger than a dot

2 Answers2