How do I add curly arrows with labels to a table of numbers?

Question

I want to add curved arrows with numbers underneath them, to a table of numbers, as shown below: !

Any suggestions as to how to do this in LaTeX, please? I want the arrows and the numbers below the arrows to all line up correctly. So far, I have just created the diagram in Excel and then pasted it into Paint and then used \includegraphics command, which produces a rather poor quality image in LaTeX. Excel doesn't allow you to align the numbers below the arrows correctly, as far as I can tell, otherwise I would just use an Excel add-in to convert the table (including the arrows etc.) to LaTeX.

Answer 1

One option using the tikzmark library from TikZ; place some marks in the desired locations in the table and use \DrawArrow to place the arrow:

The syntax for \DrawArrow is

\DrawArrow[<options>]{<start mark>}{<end mark>}{<text>}

The code:

\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{tikzmark,arrows.meta}

\newcommand\DrawArrow[4][]{
\begin{tikzpicture}[
  remember picture,
  overlay,
  arr/.style={draw=gray,line width=3pt, {-latex}, #1}
]
\draw[arr]
  ([shift={(15pt,-1ex)}]pic cs:#2) 
    to[out=-40,in=220] node[below=3pt] {#4} 
  ([shift={(6pt,-1ex)}]pic cs:#3); 
\end{tikzpicture}
}

\begin{document}

\DrawArrow{start1}{start2}{1}
\DrawArrow{start2}{start3}{6}
\DrawArrow[cyan]{start3}{start4}{12}

\noindent
\begin{tabular}{llll}
column1 & column2 & column3 & column4 \\
column1 & column2 & column3 & column4 \\
column1 & column2 & column3 & column4 \\
\tikzmark{start1}column1 & \tikzmark{start2}column2 & \tikzmark{start3}column3 &\tikzmark{start4}column4 \\
\end{tabular}

\end{document}

Since internal calculation of coordinates is required, two compilations will be needed.