Centered Cells in Latex

Question

Hello I'm trying to use cells in latex.

image of my cell here

How do you put the "Func2" and the "-" centered in the cell?

The code I'm using is:

\begin{tabularx}{0.8\textwidth} { 
  | >{\raggedright\arraybackslash}X 
  | >{\centering\arraybackslash}X 
  | >{\raggedleft\arraybackslash}X | }
   \hline
    \multicolumn{3}{|c|}{2D - $L = 64$} \\
 \hline
 Speedup(x) & Func1 & Func2 \\
 \hline
 Func2  & 35.4  & -  \\
 \hline
 Func3  & 322.8  & 9.1  \\
  \hline
\end{tabularx}

Answer 1

You could use the tabularray package. This makes it easy to change the alignment for individual cells:

\documentclass{article}

\usepackage{tabularray}

\begin{document}

\begin{tblr}{
  width={0.8\textwidth},
  colspec={|X|X[halign=c]|X[halign=r]|}
}
   \hline
    \SetCell[c=3]{halign=c} 2D - $L = 64$ \\
 \hline
 Speedup(x) & Func1 & \SetCell{halign=c} Func2 \\
 \hline
 Func2  & 35.4  & \SetCell{halign=c} -  \\
 \hline
 Func3  & 322.8  & 9.1  \\
  \hline
\end{tblr}

\end{document}