vertical alignment of a turned cell

Question

I know using turn command and a sample code like this:

\usepackage{rotating}

\begin{turn}{90} Supervised Learning \end{turn}}

we can rotate a text inside a cell, however, I couldn't find a way to vertically center this rotated text. Any suggestions is appreciated.

Here is the sample MWE:

\begin{table}[]
    \centering
    \begin{tabular}{|>{\centering\arraybackslash}m{0.5cm}|c|>{\centering\arraybackslash}m{8cm}|}
        \hline
        \multicolumn{2}{|c|}{Classification} & References \\ \hline
        %\multirow{2}{*}{{\begin{turn}{90}Supervised Learning\end{turn}}}   
        \multirow{2}{*}{\rotatebox[origin=c]{90}{Supervised Learning}} 
\end{tabular}
    \caption{A Classification}
    \label{tab:Machine_Learning_models}
\end{table}

Answer 1

since your question seems to be unstable system ... i'm afraid that my answer will miss your point as it was Mico answer (which finish with deletion) :-( )

anyway, for exercise:

• your rotated text is taller than rest of table, so it can not bo properly centered
• easier way to rotate cell content is use \rothead macro from makecell package (for which you need to define cell height)
• vertically centering in multirow cell needs some manual tweaking

with this (and expand the table) I obtain the following result:

MWE:

\documentclass{article}
\usepackage{rotating}
\usepackage{array,makecell,multirow}

\begin{document}
\begin{table}[htb]
    \centering
    \settowidth\rotheadsize{Supervised Learning}
    \begin{tabular}{| l | c |
                     >{\centering\arraybackslash}p{8cm}|}
    \hline
\multicolumn{2}{|c|}{Classification}    &   References  \\ \hline
\multirow{8}{*}[1.5ex]{\rothead{Supervised Learning}}  
        &                               &  1            \\ \cline{2-3}
        &                               &  2            \\ \cline{2-3}
        &                               &  3            \\ \cline{2-3}
        &                               &  4            \\ \cline{2-3}
        &                               &  5            \\ \cline{2-3}
        &                               &  6            \\ \cline{2-3}
        &                               &  7            \\ \cline{2-3}
        &                               &  8            \\ \hline                \end{tabular}
\caption{A Classification}
    \label{tab:Machine_Learning_models}
\end{table}
\end{document}

Addendum: Font size of text in \rothead is determined by \headfont macro. Default value is \footnotesize. It can be changed by

\renewcommand\theadfont{\normalsize}

(or whatever size, font family and shape you like). Considering above change of font size, the relvant part of MWE become:

\documentclass{article}
\usepackage{rotating}
\usepackage{array,makecell,multirow}
\renewcommand\theadfont{\normalsize}% <-- added

\begin{document}
\begin{table}[htb]
    \centering
    \settowidth\rotheadsize{\theadfont Supervised Learning}% <-- changed
    \begin{tabular}{| l | c |
                     >{\centering\arraybackslash}p{8cm}|}
    \hline
\multicolumn{2}{|c|}{Classification}    &   References  \\ \hline
\multirow{8}{*}{\rothead{Supervised Learning}}% <-- changed
% further is the same as in above MWE

and table will looks as follows: