Vertical spacing of a table cell

Question

I want to tabulate formulas, but I find that the lines of the table cells are too close together, and this is aesthetically unsatisfactory. Example (formulae copied from wikipedia):

\begin{tabular}{|c|c|}
\hline
Cylindrical & $\displaystyle{{1 \over \rho}{\partial \over \partial\rho}\left(\rho {\partial f \over \partial \rho}\right)
+ {1 \over \rho^2}{\partial^2 f \over \partial \phi^2}  + {\partial^2 f \over \partial z^2}}$\\\hline
Spherical & $\displaystyle{{1 \over r^2}{\partial \over \partial r}\!\left(r^2 {\partial f \over \partial r}\right)
\!+\!{1 \over r^2\!\sin\theta}{\partial \over \partial \theta}\!\left(\sin\theta {\partial f \over \partial \theta}\right)
\!+\!{1 \over r^2\!\sin^2\theta}{\partial^2 f \over \partial \phi^2}}$\\\hline
\end{tabular}

gives this

and you see that the top of the formulas are chopped by the lines. Suggestions?

Answer 1

I have solved this in the past by modifying the value of \arraystretch

you can do this by adding to your source :

{\renewcommand{\arraystretch}{1.2} %<- modify value to suit your needs
\begin{tabular}{|c|c|}
...
\end{tabular}
}

Edit:

Actually having researched this a bit more it seems that having equations in the cells has unexpected behaviour, where the space is increase disproportionally at the top (value set to 3 to start getting the space at the bottom):

more recently I have started to use the tabu package to replace all tables (from tabular to tabularx to longtable). It also provide a few more controls. in this case the \tabulinesep has a much more appropirate effect on the results:

\documentclass[preview]{standalone}
   \usepackage{tabu}
   \begin{document}
   {\tabulinesep=1.2mm
   \begin{tabu} {|c|c|}
       \hline
       Cylindrical & $\displaystyle{{1 \over \rho}{\partial \over \partial\rho}\left(\rho {\partial f \over \partial \rho}\right)
       + {1 \over \rho^2}{\partial^2 f \over \partial \phi^2}  + {\partial^2 f \over \partial z^2}}$\\\hline
       Spherical & $\displaystyle{{1 \over r^2}{\partial \over \partial r}\!\left(r^2 {\partial f \over \partial r}\right)
       \!+\!{1 \over r^2\!\sin\theta}{\partial \over \partial \theta}\!\left(\sin\theta {\partial f \over \partial \theta}\right)
       \!+\!{1 \over r^2\!\sin^2\theta}{\partial^2 f \over \partial \phi^2}}$\\\hline
   \end{tabu}}
\end{document}

which produces the following result:

Answer 2

You may use a different table format, leaving out the vertical lines which are by no means necessary; you can also greatly simplify the input with a personal command for partial derivatives:

\documentclass{article}

\usepackage{booktabs,amsmath}

\newcommand{\dpder}[3][]{\dfrac{\partial^{#1}#2}{\partial #3}}

\begin{document}
\begin{tabular}{lc}
\toprule
Cartesian &
$\dpder[2]{f}{x^2}+\dpder[2]{f}{y^2}+\dpder[2]{f}{z^2}$
\\
\midrule
Cylindrical &
$\dfrac{1}{\rho} \dpder{}{\rho}{\left(\rho \dpder{f}{\rho}\right)}
  + \dfrac{1}{\rho^2} \dpder[2]{f}{\phi^2} + \dpder[2]{f}{z^2}$
\\
\midrule
Spherical &
$\dfrac{1}{r^2}\dpder{}{r}{\left(r^2 \dpder{f}{r}\right)}
  +\dfrac{1}{r^2\sin\theta}\dpder{}{\theta}{\left(\sin\theta \dpder{f}{\theta}\right)}
  +\dfrac{1}{r^2\sin^2\theta}\dpder[2]{f}{\phi^2}$
\\
\bottomrule
\end{tabular}
\end{document}

Notice how to avoid unwanted spaces in the "cylindrical" and "spherical" rows by using {\left(...\right)} (a couple of braces is sufficient instead of explicit backing up). Note also the usage of \dfrac in the definition of \dpder that avoids specifying \displaystyle (which is however not a command taking arguments, but a declaration).

With booktabs there's rarely the need to adjust the row spacing.

Answer 3

As an alternative to the outdated tabu package, the new tabularray package provides rowsep option for tables:

\documentclass{article}

\usepackage{tabularray}

\begin{document}

\begin{tblr}{|c|c|}
\hline
Cylindrical & $\displaystyle{{1 \over \rho}{\partial \over \partial\rho}\left(\rho {\partial f \over \partial \rho}\right)
+ {1 \over \rho^2}{\partial^2 f \over \partial \phi^2}  + {\partial^2 f \over \partial z^2}}$\\\hline
Spherical & $\displaystyle{{1 \over r^2}{\partial \over \partial r}\!\left(r^2 {\partial f \over \partial r}\right)
\!+\!{1 \over r^2\!\sin\theta}{\partial \over \partial \theta}\!\left(\sin\theta {\partial f \over \partial \theta}\right)
\!+\!{1 \over r^2\!\sin^2\theta}{\partial^2 f \over \partial \phi^2}}$\\\hline
\end{tblr}

\bigskip

\SetTblrInner{rowsep=4pt}

\begin{tblr}{|c|c|}
\hline
Cylindrical & $\displaystyle{{1 \over \rho}{\partial \over \partial\rho}\left(\rho {\partial f \over \partial \rho}\right)
+ {1 \over \rho^2}{\partial^2 f \over \partial \phi^2}  + {\partial^2 f \over \partial z^2}}$\\\hline
Spherical & $\displaystyle{{1 \over r^2}{\partial \over \partial r}\!\left(r^2 {\partial f \over \partial r}\right)
\!+\!{1 \over r^2\!\sin\theta}{\partial \over \partial \theta}\!\left(\sin\theta {\partial f \over \partial \theta}\right)
\!+\!{1 \over r^2\!\sin^2\theta}{\partial^2 f \over \partial \phi^2}}$\\\hline
\end{tblr}

\end{document}

Answer 4

I ended up here after googling "lyx extra space in tables for dfrac", so this is an answer for LyX, but it probably also applies to plain LaTeX code.

I use the arraystretch-command in my preamble, but if I use dfrac in a cell the vertical space will not reflect the needed hight increase.

\renewcommand*\arraystretch{1.3}

The "tabu" package seems like a good solution, but the package is not recommended by several people because the author didn't tried to maintain backward compability hard enough (as stated by jon here, but I don't know if this is true though). Also I had a hard time getting the "tabu" package to work in LyX.

Anyway,

• I found a solution to expand the vertical space in a table cell both upwards and downwards vertically by simply insering an empty box-control before the cell content.

Example code for a single 3-cell row:

\hline
Logarithms & $\ln\left(x\right)$ & %
\begin{minipage}[c][10mm][t]{0.1mm}%
%
\end{minipage}$\dfrac{1}{x}$\tabularnewline

Resulting PDF without box:

Resulting PDF with box:

I used the following settings in LyX for the box:

I hope this tip can help someone to expand their vertical cell white spaces in LaTeX!

Answer 5

With {NiceTabular} of nicematrix, you can use \arraystretch and \extrarowheight of array but you have also a key cell-space-limits.

\documentclass{article}
\usepackage{nicematrix}

\begin{document}
\begin{NiceTabular}{cc}[hvlines,cell-space-limits=3pt]
Cylindrical & $\displaystyle{{1 \over \rho}{\partial \over \partial\rho}\left(\rho {\partial f \over \partial \rho}\right)
+ {1 \over \rho^2}{\partial^2 f \over \partial \phi^2}  + {\partial^2 f \over \partial z^2}}$\\
Spherical & $\displaystyle{{1 \over r^2}{\partial \over \partial r}\!\left(r^2 {\partial f \over \partial r}\right)
\!+\!{1 \over r^2\!\sin\theta}{\partial \over \partial \theta}\!\left(\sin\theta {\partial f \over \partial \theta}\right)
\!+\!{1 \over r^2\!\sin^2\theta}{\partial^2 f \over \partial \phi^2}}$\\
\end{NiceTabular}
\end{document}