[Tex/LaTex] Creating a table in LaTeX

Question

I am fairly new to LaTeX and creating tables. I was wondering if there was a way to create a table that looks like this:

                | Method 1      |           

Threshold       |P  |Z  |W      |

value1          | value |value  |value |

value2          | value |value  |value  |

This looks bad the way I typed it because I am not sure how to do it. Threshold is its own column then method one is the title of the next column and beneath that there are 3 evaluation metrics in the column of method 1 then all of the values.

Answer 1

This looks like an easy job for siunitx (aligning of the numbers) and booktabs (design of table, avoiding vertical rules, see the manual of booktabs).

Also, take a look at the siunitx manual and the siunitx tag as this package has a lot of options and possibilities to not only typeset numbers in tables.

Code

\documentclass{article}
\usepackage{siunitx,booktabs}
\begin{document}
\sisetup{table-format=1.3}
\begin{tabular}{l S S S[table-format=1.5] }
    \toprule
    Threshold & \multicolumn{3}{c}{Method 1} \\ \cmidrule{2-4}
              & {$P$} & {$Z$} & {$W$}        \\ \midrule
    Value 1   & 0.125 & 2.635 & 3.14159      \\
    Value 2   & 1.571 & 0.123 & 2.71828      \\ \bottomrule
\end{tabular}
\end{document}

Output