# Unsqueeze the fraction

For the LaTeX code below,

 $$Fitness(\CS)= \begin{cases} 0.5 + 0.5 \cdot G(\CS) & if\ V(\CS)=0 \\ 0.5\cdot G(\CS)-\frac{V(\CS)}{V_{Tot}(\CS)} & otherwise. \end{cases}~\label{eq:fitness}$$


I get the output

It looks like the fraction \frac{V(\CS)}{V_{Tot}(\CS)} is a bit squeezed here,I would prefer

which looks less squeezed. How could I do that?

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@Werner The dcases environment is defined by mathtools – egreg Nov 21 '12 at 0:12

mathtools defined dcases which puts the entries inside in display math mode. This causes fractions and other mode-varying elements to conform to their largest size:

\documentclass{article}
% mathtools also loads amsmath (http://ctan.org/pkg/amsmath)
\usepackage{mathtools}% http://ctan.org/pkg/mathtools
\newcommand{\CS}{CS}
\DeclareMathOperator{\Fitness}{Fitness}
\begin{document}

% Original cases
$$Fitness(\CS)= \begin{cases} 0.5 + 0.5 \cdot G(\CS) & if\ V(\CS)=0 \\ 0.5\cdot G(\CS)-\frac{V(\CS)}{V_{Tot}(\CS)} & otherwise. \end{cases}\label{eq:fitness1}$$

% Updated dcases, operator definition and text
$$\Fitness(\CS)= \begin{dcases} 0.5 + 0.5 \cdot G(\CS) & \text{if\ }V(\CS)=0 \\ 0.5\cdot G(\CS)-\frac{V(\CS)}{V_{\text{Tot}}(\CS)} & \text{otherwise.} \end{dcases}\label{eq:fitness2}$$

\end{document}


Textual elements are forced as text using \text, while an operator like Fitness should also be declared as such. See the amsmath documentation for more on these topics.

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