Increase vertical space in table

Question

Creating a table using tabulary I am confronted with the problem that the lines of my table are too small, resulting in that the formulas touch the borders of the table. The code I used is given below.

\documentclass{scrartcl}
\usepackage[utf8]{inputenc}
\usepackage{tabulary}
\usepackage{booktabs}
\usepackage{tabularx}

\begin{document}

\centering
\begin{tabulary}{18cm}{R|L L L}
\toprule
\hline
Mean squared error & MSE &= &$\frac{1}{n}\sum_{t=1}^{n}e_t^2$   \\
\hline
Root mean squared error & RMSE &= &$\sqrt{\frac{1}{n}\sum_{t=1}^{n}e_t^2}$ \\
\hline
Mean absolute error & MAE &= &$\frac{1}{n}\sum_{t=1}^{n}|e_t|$ \\
\hline
Mean absolute percentage error & MAPE &= &$\frac{100\%}{n}\sum_{t=1}^{n}\left |\frac{e_t}{y_t}\right|$\\
\hline\bottomrule
\end{tabulary}
\end{document}

How can I increase vertical space in my table so that it looks appropriate?

Answer 1

Don't use \hline and also remove the vertical rule that adds no information and simply interrupts the flow of reading.

\documentclass{scrartcl}
\usepackage[utf8]{inputenc}
\usepackage{tabulary}
\usepackage{booktabs}
\usepackage{amsmath}

\begin{document}

\centering
\begin{tabulary}{18cm}{L R @{} >{${}}c<{{}$} @{} L}
\toprule
Mean squared error & MSE &= &$\displaystyle\frac{1}{n}\sum_{t=1}^{n}e_t^2$   \\
\midrule
Root mean squared error & RMSE &= &$\displaystyle\sqrt{\frac{1}{n}\sum_{t=1}^{n}e_t^2}$ \\
\midrule
Mean absolute error & MAE &= &$\displaystyle\frac{1}{n}\sum_{t=1}^{n}|e_t|$ \\
\midrule
Mean absolute percentage error & MAPE &= &$\displaystyle\frac{100\%}{n}\sum_{t=1}^{n}\left |\frac{e_t}{y_t}\right|$\\
\bottomrule
\end{tabulary}
\end{document}

I'm not sure you really need tabulary: this gives exactly the same result.

\documentclass{scrartcl}
\usepackage[utf8]{inputenc}
\usepackage{array}
\usepackage{booktabs}
\usepackage{amsmath}

\begin{document}

\centering
\begin{tabular}{l r @{} >{${}}c<{{}$} @{} l}
\toprule
Mean squared error & MSE &= &$\displaystyle\frac{1}{n}\sum_{t=1}^{n}e_t^2$   \\
\midrule
Root mean squared error & RMSE &= &$\displaystyle\sqrt{\frac{1}{n}\sum_{t=1}^{n}e_t^2}$ \\
\midrule
Mean absolute error & MAE &= &$\displaystyle\frac{1}{n}\sum_{t=1}^{n}|e_t|$ \\
\midrule
Mean absolute percentage error & MAPE &= &$\displaystyle\frac{100\%}{n}\sum_{t=1}^{n}\left |\frac{e_t}{y_t}\right|$\\
\bottomrule
\end{tabular}
\end{document}

Answer 2

Without tabulary (works also with tabulary

\documentclass{scrartcl}
\usepackage[utf8]{inputenc}
\usepackage{array,booktabs}
\usepackage{amsmath}

\begin{document}

{\def\arraystretch{2.5}
\begin{tabular}{@{} l r @{} >{${}}c<{{}$} @{} l @{}}
\toprule
Mean squared error & MSE &= &$\dfrac{1}{n}\sum\limits_{t=1}^{n}e_t^2$   \\
\midrule
Root mean squared error & RMSE &= &$\sqrt{\dfrac{1}{n}\sum\limits_{t=1}^{n}e_t^2}$ \\
\midrule
Mean absolute error & MAE &= &$\dfrac{1}{n}\sum\limits_{t=1}^{n}|e_t|$ \\
\midrule
Mean absolute percentage error & MAPE &= &$\dfrac{100\%}{n}\sum\limits_{t=1}^{n}\left |\frac{e_t}{y_t}\right|$\\
\bottomrule
\end{tabular}}

\end{document}

Answer 3

The cellspace package ensures a minimal spacing between the top of a cell and the bottom of the above cell and independantly between the bottom of the cell and the top of the below cell. So you can have better vertical spacing of cells and contents of cells vertically centred, which is not the case if you play with \arraystretch. Makecell allows for horizontal lines of varying thickness, with the Xhline command.

In addition I simplified the original code (1 column less): \documentclass{scrartcl} \usepackage[utf8]{inputenc} \usepackage{tabulary} \usepackage{booktabs} \usepackage{amsmath}

\usepackage{cellspace}
\setlength{\cellspacetoplimit}{6pt}
\setlength{\cellspacebottomlimit}{6pt}

\usepackage{makecell}
\newcommand*{\topdblline}{\Xhline{0.15ex}\\[-2.6ex]\hline}
\newcommand*{\botdblline}{\hline\\[-2.6ex]\Xhline{0.15ex}}

\begin{document}

\centering
\begin{tabulary}{18cm}{L @{\qquad}R @{${}={}$} >{$\displaystyle}SL<{$}}%{L R @{} >{${}}c<{{}$} @{} SL}
\topdblline
Mean squared error & MSE  & \frac{1}{n}\sum_{t=1}^{n}e_t^2    \\
\hline
Root mean squared error & RMSE & \sqrt{\frac{1}{n}\sum_{t=1}^{n}e_t^2}  \\
\hline
Mean absolute error & MAE &  \frac{1}{n}\sum_{t=1}^{n}|e_t|  \\
\hline
Mean absolute percentage error & MAPE & \frac{100\%}{n}\sum_{t=1}^{n}\left |\frac{e_t}{y_t}\right| \\
\botdblline
\end{tabulary}

\end{document}