How to align rotated column headings in a table?

Question

I have this code which I adapted from Big table with rotated column labels using booktabs:

\usepackage{booktabs}
\begin{document}

\begin{table*}  
\centering
\begin{tabular}{cccccccccc}  

\toprule  
& \multicolumn{2}{>{\begin{minipage}[c]{2cm}}l<{\end{minipage}}}{\centering Group 1\\ some subtitle}
& \multicolumn{4}{>{\begin{minipage}[c]{2cm}}l<{\end{minipage}}}{\centering Group 2\\ some subtitle}
& \multicolumn{3}{>{\begin{minipage}[c]{2cm}}l<{\end{minipage}}}{\centering Group 3\\ some subtitle} \\

 \cmidrule(lr){2-3} \cmidrule(lr){4-7}\cmidrule(lr){8-10}

& \multicolumn{1}{>{\begin{turn}{90}\begin{minipage}[c][0.5cm][c]{2cm}}l<{\end{minipage}\end{turn}}}{some heading\\ blabla}
& \multicolumn{1}{>{\begin{turn}{90}\begin{minipage}[c][0.5cm][c]{2cm}}l<{\end{minipage}\end{turn}}}{not correctly\\ aligned with data}
& \multicolumn{1}{>{\begin{turn}{90}\begin{minipage}[c][0.5cm][c]{2cm}}l<{\end{minipage}\end{turn}}}{some heading \\ blabla}
& \multicolumn{1}{>{\begin{turn}{90}\begin{minipage}[c][0.5cm][c]{2cm}}l<{\end{minipage}\end{turn}}}{some heading}
& \multicolumn{1}{>{\begin{turn}{90}\begin{minipage}[c][0.5cm][c]{2cm}}l<{\end{minipage}\end{turn}}}{some heading}
& \multicolumn{1}{>{\begin{turn}{90}\begin{minipage}[c][0.5cm][c]{2cm}}l<{\end{minipage}\end{turn}}}{some heading\\ this one is long}
& \multicolumn{1}{>{\begin{turn}{90}\begin{minipage}[c][0.5cm][c]{2cm}}l<{\end{minipage}\end{turn}}}{some heading}
& \multicolumn{1}{>{\begin{turn}{90}\begin{minipage}[c][0.5cm][c]{2cm}}l<{\end{minipage}\end{turn}}}{some heading}
& \multicolumn{1}{>{\begin{turn}{90}\begin{minipage}[c][0.5cm][c]{2cm}}l<{\end{minipage}\end{turn}}}{some heading\\ this one is long}\\

\midrule

Sample1 & 122 & 109 &  0 & 0 & 55 & 48 & 63 & 61 & 1 \\
Sample2 & 122 & 109 &  0 & 0 & 55 & 48 & 63 & 61 & 1 \\ 
Sample3 & 122 & 109 &  0 & 0 & 55 & 48 & 63 & 61 & 1 \\ 
Sample4 & 122 & 109 &  0 & 0 & 55 & 48 & 63 & 61 & 1 \\ 

\midrule
Total   & 122 & 109 &  0 & 0 & 55 & 48 & 63 & 61 & 1 \\ 

\bottomrule

\end{tabular}
\end{table*}
\end{document}

It generates this:

Here are a few things I'm not so sure how to do:

1) The "Group 2" and "Group 3" headings are not correctly centered. I would like each "Group x" heading to be centered whatever is the number of columns below that heading.

2) The second rotated sub-heading for Group 1 is not properly aligned with the data. I would like each rotated sub-heading to be aligned with the corresponding data.

3) Additionally, I would like to insert a (small) blank column between each group (for instance, between Group 1 and Group 2).

Answer 1

You can have a much simpler code with the makecell package, using its \rothead command without having to use a minipage. Set the width of the rotated headings to the length of the longest heading line, and the trick is done. The makecell package allows for line breaks in cells while keeping them centred (by default) both vertically and horizontally.

In addition, I use the cellspace package to ensure a minimal spacing above and below the contents of a column cell if the specifier of this column is prefixed with the letter S.

 \documentclass{article}
\usepackage{array, booktabs}
\usepackage{rotating}
\usepackage{makecell}
\renewcommand\theadfont{\normalsize}

\usepackage{cellspace}
\setlength\cellspacetoplimit{3pt}
\setlength\cellspacebottomlimit{3pt}

\begin{document}

\begin{table*}
\settowidth\rotheadsize{\theadfont aligned with data}
\centering
\begin{tabular}{Scc@{\hskip 1pt}cc@{\hskip 3pt}cc@{\hskip 3pt}ccc@{\hskip 3pt}c}
\toprule
& \multicolumn{2}{c}{\thead{Group 1\\some subtitle}}
& \multicolumn{4}{c}{\thead {Group 2\\ some subtitle}}
& \multicolumn{3}{c}{\thead {Group 3\\ some subtitle}} \\
 \cmidrule(lr){2-3} \cmidrule(lr){4-7}\cmidrule(lr){8-10}
& \rothead{some heading\\[-0.5ex] blabla}
& \rothead{now correctly\\[-0.5ex] aligned with data}
& \rothead{some heading \\[-0.5ex] blabla}
& \rothead{some heading}
& \rothead{some heading}
& \rothead{some heading\\[-0.5ex] this one is long}
& \rothead{some heading}
& \rothead{some heading}
& \rothead{some heading\\[-0.5ex] this one is long}\\
\midrule
\addlinespace
Sample1 & 122 & 109 & 0 & 0 & 55 & 48 & 63 & 61 & 1 \\
Sample2 & 122 & 109 & 0 & 0 & 55 & 48 & 63 & 61 & 1 \\
Sample3 & 122 & 109 & 0 & 0 & 55 & 48 & 63 & 61 & 1 \\
Sample4 & 122 & 109 & 0 & 0 & 55 & 48 & 63 & 61 & 1 \\
\midrule
Total & 122 & 109 & 0 & 0 & 55 & 48 & 63 & 61 & 1 \\
\addlinespace
\bottomrule
\end{tabular}
\end{table*}

\end{document}