The formula alignment across a table column

Question

I use the following code to produce a LaTeX output.

‎\documentclass[12pt]{report}‎‎‎
‎\usepackage{amsmath}‎‎

‎\newcommand*\sumta[2]{\mathop {\sum} \limits_{#1}^{#2}}‎‎
‎\newcommand*\bnsar[2]{_{#1}^{#2}}‎‎

\begin{document}‎
\begin{table}[!ht]
\centering
\caption{Time domain features}
\label{table.1}
\begin{tabular}{l|l}
\hline
Feature & Formula \\ \hline
Mean value & ‎$‎\overline{x}=‎\frac{1}{N}‎\sumta{i=1}{N}x_i‎‎‎‎$‎  \\
Standard deviation & ‎$‎\sigma = ‎‎\sqrt{‎\frac{1}{N}‎\sumta{n=1}{N}(x_i - ‎\overline{x})^2‎‎‎}‎‎‎$‎  \\
Kurtosis & ‎$\text{K}=‎\frac{1}{N}‎\sumta{i=1}{N}‎\frac{(x_i‎‏-\overline{x})^4‎}{‎\sigma‎^4}‎‎‎$‎  \\
Skewness & ‎$\text{Sk} = ‎\frac{1}{N}‎\sumta{i=1}{N}‎\frac{(x_i-‎\overline{x})^3‎}{‎\sigma‎^3}‎‎‎$‎ \\
Root mean square & ‎$\text{RMS} = ‎\sqrt{‎\frac{1}{N}‎\sumta{i=1}{N}x‎\bnsar{i}{2}‎‎‎}‎$‎ \\
Crest factor & ‎$\text{Crf} = ‎\frac{\max \text{value}}{\text{RMS}}‎$‎ \\
Peak to Peak value & ‎$\text{PPV} = \max \text{value} - \min \text{value}$‎ \\ \hline
\end{tabular}
\end{table}‎
\end{document}

As you see, each row is consisted of two columns. The expressions in the right column are all in Math mode. How may I align the equations for a specific operator across a column in LaTeX? For example, I want the equation marks to be aligned vertically across the column cells to produce an output alike the picture below.

I've reviewed other suggestions available, but they simply are not what I mean! Please help me through the issue.

Thank you.

score 5 · Accepted Answer · answered Feb 21 '18 at 14:05

you should provide complete small document with all your definitions used in table
given one doesn't work
i add two packages used for improved your table looks

\documentclass{article}
\usepackage{array, makecell}   % new
\setcellgapes{5pt}             % new
\usepackage[skip=1ex]{caption} % new


\begin{document}
    ‎\begin{table}[!ht]
\centering
\makegapedcells    % new
    \caption{Time domain features}
\label{table.1}
    \begin{tabular}{l| >{$}r<{$} @{\hspace{2.2pt}} >{$}l<{$}}
    \hline
Feature             & \multicolumn{2}{c}{Formula}                               \\ 
    \hline
Mean value          & ‎‎\overline{x}  & = ‎\frac{1}{N}‎\sum_{i=1}^{N}x_i            \\
Standard deviation  & ‎‎\sigma        & = ‎‎\sqrt{‎\frac{1}{N}
                                        ‎\sum_{i=1}^{N}(x_i - ‎\overline{x})^2‎‎‎}   \\
Kurtosis            & \mathrm{K}    & = ‎\frac{1}{N}‎\sum_{i=1}^{N}
                                        ‎\frac{(x_i‎‏-\overline{x})^4‎}{‎\sigma‎^4}   \\
Skewness            & ‎\mathrm{Sk}   & = ‎\frac{1}{N}‎\sum_{i=1}^{N}
                                        ‎\frac{(x_i-‎\overline{x})^3‎}{‎\sigma‎^3}‎‎‎   \\
Root mean square    & ‎\mathrm{RMS}  & = ‎\sqrt{‎\frac{1}{N} 
                                        ‎\sum_{i=1}^{N} (x_-\overline{x})^2 }    \\
Crest factor        & \mathrm{Crf}  & = ‎\frac{\max \mathrm{value}}{\mathrm{RMS}}‎  \\
Peak to Peak value  & \mathrm{PPV}  & = \max \mathrm{value} - \min \mathrm{value} \\ 
    \hline
\end{tabular}
    \end{table}‎
\end{document}

what is wrong with this: it is simple :-). it might exist, but i don't aware on it. — Zarko, Feb 21 '18 at 15:48
For coloring the rows, look at this: https://tex.stackexchange.com/questions/378268/makegapedcells-disables-rowcolor, \makegapedcells have problem with coloring the table. — Qaher, Feb 22 '18 at 05:55
@Qaher, where you have any table coloring? i'm aware of this problem. — Zarko, Feb 22 '18 at 07:50
It was because I've asked about other available solutions to get the same result. — Qaher, Feb 22 '18 at 09:02

score 5 · Answer 2 · answered Feb 21 '18 at 14:56

Some improvements with booktabs and medium sized formulæ with nccmath. In addition, I think \bar{x} looks better than \overline{x}:

\documentclass{article}
\usepackage{mathtools, nccmath}
\usepackage{array, makecell, booktabs} % new%
\setcellgapes{5pt} % new
\usepackage[skip=1ex]{caption} % new
\newcommand\msum{\medop\sum\limits}

\begin{document}
    ‎\begin{table}[!ht]
\centering%
\makegapedcells % new
    \caption{Time domain features}
\label{table.1}
    \begin{tabular}{@{}r @{\qquad}>{$}r<{$} @{} >{${}}l<{$}@{}}
    \toprule
\multicolumn{1}{c}{Feature} & \multicolumn{2}{c}{Formula} \\
    \midrule
Mean value & ‎‎\bar{x} & = ‎\mfrac{1}{N}‎\msum_{i=1}^{N}x_i \\
Standard deviation & ‎‎\sigma & = ‎‎\sqrt{‎\mfrac{1}{N}
                                       ‎\msum_{i=1}^{N}(x_i - ‎\bar{x})^2‎‎‎} \\
Kurtosis & \mathrm{K} & = ‎\mfrac{1}{N}\medop‎\sum_{i=1}^{N}
                                        ‎\mfrac{(x_i‎‏-\bar{x})^4‎}{‎\sigma‎^4} \\
Skewness & ‎\mathrm{Sk} & = ‎\mfrac{1}{N}‎\msum_{i=1}^{N}
                                        ‎\mfrac{(x_i-‎\bar{x})^3‎}{‎\sigma‎^3}‎‎‎ \\
Root mean square & ‎\mathrm{RMS} & = ‎\sqrt{‎\mfrac{1}{N}
                                        \msum_{i=1}^{N} (x_-\bar{x})^2 } \\
Crest factor & \mathrm{Crf} & = ‎\mfrac{\max \mathrm{value}}{\mathrm{RMS}}‎ \\
Peak to Peak value & \mathrm{PPV} & = \max \mathrm{value} - \min \mathrm{value} \\
    \bottomrule
\end{tabular}
    \end{table}‎

\end{document}

The formula alignment across a table column

2 Answers2