Table cell center alignment other than decimal point in dcolumn

Question

How do I align the cell contents of a dcolumn-Type central at a specified point other than the decimal point (e.g. the second decimal place)?

I have a table of the following structure:

\begin{table}[!htbp] \centering 
\begin{tabular}{l*{2}{D{.}{.}{-1}}} 
\hline
  & \multicolumn{1}{c}{This is centered text . This is centered text} & \multicolumn{1}{c}{Narrow} \\
\hline 
 \textit{Measure1} & 0.001 & 0.001\\ 
  & (0.001) & (0.001) \\ 
 \textit{Measure2} &  -0.006^{**} &  -0.006^{**}\\ 
\hline
\end{tabular} 
\end{table}

The multicolumn content is aligned center while the dcolumn content is aligned centered around the ".", which is perfectly fine. However, if I have a Narrow column as shown, the content of the dcolumn-cell looks weirdly aligned due to its three decimal places (and potential **, (), etc.)

Do you have and idea how to resolve this issue? Workarounds like adding extra-spaceholders may also help.

Thanks in advance

Answer 1

I think the real solution (as opposed to just treating some symptoms) is not to use D{.}{.}{-1} for all columns for which alignment on the decimal markers is supposed to be performed. Instead, taylor the argument of the D column type to the properties of the numbers actually encountered in the respective columns.

\documentclass{article}
\usepackage{dcolumn}
\newcolumntype{d}[1]{D..{#1}} % d{2.5}: reserve 2 digits before and 5 digits after decimal marker

\begin{document}
\begin{table}[!htbp] 
\centering
\begin{tabular}{l d{-1} d{2.5} }
\hline
  & \multicolumn{1}{c}{This is centered text. This is centered text.}
  & \multicolumn{1}{c}{Narrow} \\
\hline
 \textit{Measure 1} & 0.001 & 0.001\\
  & (0.001) & (0.001) \\
 \textit{Measure 2} &  -0.006^{**} &  -0.006^{**}\\
\hline
\end{tabular}
\end{table}
\end{document}