# manually controlling height of the horizontal line of the radix or root symbol

While using lucida fonts, I have big problems with the height of the horizontal line of the radix or root symbol. Sometimes $\sqrt[x^2 + x}$ comes out allright, but for example, in a fraction $\frac{x^2 + x}{x^2 + x}$, the exponents "2" stick literally to the horizontal radix line. I tried to fix that using a vertical strut

$\newcommand{\S}{\rule[0pt]{0pt}{1.6 ex}}$


and variants of it and write

$\frac{ \sqrt{\S x^2 + x} }{ \sqrt{\S x^2 + x} }$


but this does not help. Does anyone have better ideas?

• Welcome to TeX.SX! Especially with font questions it is never a bad idea to add an MWE that reproduces the issue and maybe even a picture of the output, so we can compare what we get with what you see. – moewe Apr 29 '15 at 6:55
• I can't really see the issue: look at this picture. – egreg Apr 29 '15 at 11:21
• @egreg -- op is using lucida fonts. lucida dimensions are rather different from those of cm. – barbara beeton Apr 29 '15 at 16:04

With the Lucida Math font (for pdflatex), here's what I get from the following code

\documentclass{article}
\usepackage{amsmath}
\usepackage{lucimatx}

\begin{document}

$\frac{ \sqrt{x^2 + x} }{ \sqrt{x^2 + x} }$

$\frac{ \sqrt{\mathstrut x^{2} + x} }{ \sqrt{x^{\mathstrut 2} + x} }$

\end{document}


I don't find the first display particularly squashed together; the impression might be given when looking at the result at low resolution (that is, on the screen without magnification).

In the second display I suggest two (manual) methods for obtaining more room.

If I use the OpenType version, I get from

\documentclass{article}
\usepackage{amsmath}

\usepackage{unicode-math}
\setmathfont{Lucida Bright Math OT}

\begin{document}

$\frac{ \sqrt{x^2 + x} }{ \sqrt{x^2 + x} }$

\end{document}


the following picture, which shows perhaps better spacing.

• is the lucida \mathstrut really so enormous as it appears in the numerator of the second example? if so, i suspect a bug in the metrics. – barbara beeton Apr 29 '15 at 16:32
• @barbarabeeton Possibly so. I'm just the messenger. ;-) – egreg Apr 29 '15 at 16:33