Aligning Decimal Points in Table

Question

I want to align two numbers in two different rows the decimal point.

I do see a link for that here: Aligning numbers by decimal points in table columns

However, I don't understand how to incorporate that into my code. What follows is a reduced version of my code.

\documentclass[12pt,english]{article}
\usepackage{longtable}
\usepackage{fullpage}
\usepackage{times}
\usepackage[flushleft]{threeparttable}
\usepackage[font=large,labelfont=bf,tableposition=top,textfont=bf]{caption}
\usepackage{tabularx}
\usepackage{booktabs}
\newcolumntype{C}{>{\centering\arraybackslash}X}

\begin{document}

\clearpage \newpage
\begin{table}[!ht]
\caption{Table Title}
\def\arraystretch{1.05}
\vspace{-0.2cm}
\begin{threeparttable}
\small
\begin{tabularx}{\textwidth}{l*{10}{C}}
\hline \hline \addlinespace
& (1)  \\  
Variable Name & 0.1234566  \\
& (0.1234566) \\
\hline \hline \addlinespace
 \end{tabularx}
\begin{tablenotes}
\vspace{0.1cm}
\footnotesize{

\item \noindent \hspace{-1.8mm} Notes: 

 \noindent Sources: 
 }
\end{tablenotes}
\end{threeparttable}
\end{table}

\end{document}

Answer 1

In addition to trying out the dcolumn package mentioned by @DavidCarlisle, you may also want to check out some of the capabilities of the siunitx package, specifically, its S column type. I've simplified your (not exactly minimal) working example to the example code below, in order to focus on the operation of this column type:

\documentclass[12pt]{article}
\usepackage{booktabs,mathptmx,siunitx}
\sisetup{input-symbols = {()},  % do not treat "(" and ")" in any special way
         group-digits  = false} % no grouping of digits
\begin{document}
\begin{table}
  \begin{tabular}{@{}l S[table-format=2.7] S[table-format=4.2] @{}}
    \toprule
    & \multicolumn{1}{c}{(1)} & \multicolumn{1}{c@{}}{(2)}  \\  
    \midrule
    Variable Name & 98.1234567 & 1234.56  \\
    & (0.6789) & (54.3)\\
    \bottomrule
  \end{tabular}
\end{table}
\end{document}

Answer 2

It looks like you don't want tabularx at all, just use a normal tabular with a D column for your numeric columns, perhaps defined by

\newcolumntype{.}{D{.}{.}{-1}}

using the dcolumn package.

for completeness, complete example:

\documentclass[12pt]{article}
\usepackage{booktabs,dcolumn}

\begin{document}
\begin{table}
  \begin{tabular}{@{}l*{2}{D{.}{.}{7}}@{}}
    \toprule
    & (1) & (2)  \\  
    \midrule
    Variable Name & 98.1234567 & 1234.56  \\
    & (0.6789) & (54.3)\\
    \bottomrule
  \end{tabular}
\end{table}
\end{document}

Answer 3

I thought I'd add my answer because it doesn't make use of any other packages (although I think using dcolumn is the easiest solution). What you can do is break each number column into two columns, one for the abscissa (left of the decimal) and one for the ordinate (right). Then, right align the first column, left align the second, and squeeze the space between them with @{}.

Specifically, this is option 1 in the question you linked.

I think the appropriate minimum solution is

\documentclass{article}
\begin{document}
\begin{table}
\begin{tabular}{lr@{}lr@{}l}
\hline
& \multicolumn{2}{c}{(1)} & \multicolumn{2}{c}{(2)}  \\  
\hline
Variable Name & 98 & .1234567 & 1234 & .56  \\
              & (0 & .6789)   &  (54 & .3)  \\
\hline
\end{tabular}
\end{table}
\end{document}

Answer 4

A simple workaround for when you don't have too many entries (or if you don't mind auto-substituting a piece of text into every line) is to pad with \phantom{} (which has the effect of taking up as much space as its argument would have taken, but will not show anything). For example:

\documentclass{article}
\usepackage{booktabs}
\begin{document}
\begin{tabular}{rrr}
& (1) & (2) \\  
\midrule
Variable Name & 98.1234567           & 1234.56 \\
              & (0.6789)\phantom{67} &  (54.3) \\
\bottomrule
\end{tabular}
\end{document}