Carissimi, l’uso che faccio del formidabile TikZ è molto elementare.
`\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{matrix,patterns}
\begin{document}
\begin{center}
\begin{tikzpicture}[x=5mm,y=5mm]
\matrix (a)[matrix of nodes, nodes in empty cells,nodes={ text width=8mm, text depth=1mm, text centered}]{
& $1$ & $-3$ & $-3$ & $-4$ \\
$4$ & & $4$ & $4$ & $4$ \\
& $1$ & $1$ & $1$ & $0$ \\
};
\begin{scope}[blue]
\draw (a-1-2.north west)–(a-3-1.south east);
\draw (a-2-1.south west)–(a-2-5.south east);
\draw (a-1-4.north east)–(a-3-4.south east);
\end{scope}
\end{tikzpicture}
\end{center}
\begin{center}
\begin{tikzpicture}[font=\small,x=10mm, y=10mm]
\draw [->] (0,0) — (8,0) node [below right] () {$r$};
\foreach \x in {2,4,6}{
\draw (\x,3pt)–(\x,-3pt);
\begin{scope} [dotted]
\draw (\x,0) — (\x,-3.5);
\end{scope}}
\node
at (0,-0.5) {$F_1$};
\node
at (0,-1) {$F_2$};
\node
at (0,-1.5) {$F_3$};
\node
at (0,-2.5) {$P$};
\node
at (0,-3.0) {$\mathcal{S}$};
\node [above] at (2,0) {$-3$};
\node [above] at (4,0) {$0$};
\node [above] at (6,0) {$3$};
\node at (1,-0.5) {$-$};
\node at (3,-0.5) {$-$};
\node at (5,-0.5) {$+$};
\node at (7,-0.5) {$+$};
\node at (1,-1) {$-$};
\node at (3,-1) {$-$};
\node at (5,-1) {$-$};
\node at (7,-1) {$+$};
\node at (1,-1.5) {$-$};
\node at (3,-1.5) {$+$};
\node at (5,-1.5) {$+$};
\node at (7,-1.5) {$+$};
\node at (1,-2.5) {$-$};
\node at (3,-2.5) {$+$};
\node at (5,-2.5) {$-$};
\node at (7,-2.5) {$+$};
\draw [fill] (4,-0.5) circle (2.0pt);
\draw [fill] (6,-1) circle (2.0pt);
\draw [fill] (2,-1.5) circle (2.0pt);
\draw [fill] (2,-2.5) circle (2.0pt);
\draw [fill] (4,-2.5) circle (2.0pt);
\draw [fill] (6,-2.5) circle (2.0pt);
\pattern [pattern= north east lines, pattern color=blue!75!white] (0,-3) rectangle (2,-3.5);
\pattern [pattern= north east lines, pattern color=blue!75!white] (4,-3) rectangle (6,-3.5);
\draw [blue,ultra thick] (0,-3.0) — (2,-3.0);
\draw [blue,ultra thick] (4,-3.0) — (6,-3.0);
\draw [blue,fill=white,very thick] (2,-3.0) circle (2.0pt);
\draw [blue,fill=white,very thick] (4,-3.0) circle (2.0pt);
\draw [blue,fill=white,very thick] (6,-3.0) circle (2.0pt);
\end{tikzpicture}
\end{center}
\end{document}`
Vorrei migliorare i risultati precedenti: quello non non va bene è l’incolonnamento dei numeri nella prima tabella, e delle lettere nella seconda. Nel primo caso vorrei che i numeri fossero allineanti a destra (e non a sinistra), nel secondo caso vorrei che le lettere fossero centrate verticalmente.
Come fare?
Ah, più la soluzione è semplice, più la apprezzo!! 😉