Text Formatting ⇒ White Space outside Parentheses

[niles]

Hi

Please see my MWE:

Code: Select all

\documentclass[a4paper]{article}
\usepackage{amsmath} 
\usepackage[sc]{mathpazo}

\begin{document}
I have a function  
\begin{align}
f(x) = \left(\sqrt{ \frac{x}{20}} \right),
\end{align}
which is good.
\end{document}

What bothers me is the white space between the last paranthesis and the comma. Is there a clever way to remove it, or do I have to resort to \! every time?

Best,
Niles.

[Stefan Kottwitz]

Hi Niles,

very good MWE! Nice for testing.

This spacing problem with \left ... \right could be fixed by

• enclosing the expression in braces:

  Code: Select all

  f(x) = {\left(\sqrt{ \frac{x}{20}} \right)},

• inserting negative space before the comma as quick fix:

  Code: Select all

  f(x) = \left(\sqrt{ \frac{x}{20}} \right)\!, 

• or by using \biggl( and \biggr) instead.

The first suggestion seems to be the cleanest to me. The enclosed expression would be treated like ordinary math regarding spacing, resulting in less space after it. It's also logical, as the comma is not part of the expression.

Stefan

[localghost]

The following redefinition of the \left and \right command pair at first sight seems to have the desired effect.

Code: Select all

\documentclass[a4paper]{article}
\usepackage{amsmath}
\usepackage[sc]{mathpazo}

\let\Right\right
\let\Left\left
\makeatletter
\def\right#1{\Right#1\@ifnextchar){\!\!\right}{}}
\def\left#1{\Left#1\@ifnextchar({\!\!\left}{}}
\makeatother

\begin{document}
  I have a function
  \begin{align}
    f(x) &= \left(\sqrt{\frac{x}{20}}\right),
  \end{align}
  which is good.
\end{document}

But it becomes ugly when there are other characters than e. g. punctuation marks.

Code: Select all

\documentclass[a4paper]{article}
\usepackage{amsmath}
\usepackage[sc]{mathpazo}

\let\Right\right
\let\Left\left
\makeatletter
\def\right#1{\@ifnextchar){\Right}{}#1\!\!}
\def\left#1{\@ifnextchar({\!\!\Left}{}#1}
\makeatother

\begin{document}
  I have a function
  \begin{align}
    x \left(\sqrt{\frac{x}{20}}\right) y
  \end{align}
  which is good.
\end{document}

So I would use this with caution. You either have to balance superfluous space with negative space or missing space with additional space. This could end up in a vicious circle. And so the proposal of Stefan might be better.


Thorsten

[niles]

Thanks for the help to both of you. I'll try with Stefan's first suggestion.

Best wishes,
Niles.