Kdjykuj

How can I give names to all intersection points of a grid, so that I can draw from a specific intersection to another. So when changing the xstep/ystep measures the drawing refers to the new intersection positioning not the absolute coordinates.

In my example, when changing the xstep/ystep measures the drawings remain in their positions and do not change with the xstep/ystep measures.

So I want to draw from intersection a to intersection b, not from position (1,1) to (2,2); and from intersection x to intersection z, not from position (3,3) to (4,3)

Can this be done without using an extra package, because I can not install new packages (on my workplace computer) for security reasons.

documentclass{beamer}

setbeamertemplate{navigation symbols}{}

usepackage{tikz}

usepackage{pgfplots}

begin{document}

begin{frame}[t]

frametitle{N}

begin{center}

begin{tikzpicture}

draw[step=.5cm,color=gray] (0,0) grid (8,8);

draw<2->[ultra thick, green, -latex] (1,1) -- (2,2);

draw[blue!40!black, thick, fill=blue!40!white, opacity=.5] (3,3) circle (.2cm) node (c){};

draw<3->[ultra thick, red, -latex] (c.center) -- (4,3);

node at (1,1){a};

node at (2,2){b};

node at (3,3){x};

node at (4,3){z};

end{tikzpicture}

end{center}

end{frame}

end{document}

If you remove the units from the steps and do, say, begin{tikzpicture}[x=2cm,y=2cm] this will increase the step of the grid while keeping the same intersections (or lattice nodes) connected.

documentclass{beamer}

setbeamertemplate{navigation symbols}{}

usepackage{tikz}

usepackage{pgfplots}

begin{document}

begin{frame}[t]

frametitle{N}

begin{center}

begin{tikzpicture}[x=2cm,y=2cm]

draw[step=.5,color=gray] (0,0) grid (5,4);

draw<2->[ultra thick, green, -latex] (1,1) -- (2,2);

draw[blue!40!black, thick, fill=blue!40!white, opacity=.5] (3,3) circle (.2cm) node (c){};

draw<3->[ultra thick, red, -latex] (c.center) -- (4,3);

node at (1,1){a};

node at (2,2){b};

node at (3,3){x};

node at (4,3){z};

end{tikzpicture}

end{center}

end{frame}

end{document}

I am not sure I understand your question. Would something like this work?

documentclass{beamer}

setbeamertemplate{navigation symbols}{}

usepackage{tikz}

usepackage{pgfplots}

begin{document}

begin{frame}[t]

    frametitle{N}

    begin{center}

        begin{tikzpicture}

            draw[step=.5cm,color=gray] (0,0) grid (8,8);

            % define coords

            coordinate(a) at (1,1);

            coordinate(b) at (2,2);

            coordinate(x) at (3,3);

            coordinate(z) at (4,3);

            % use them 

            node at (a){a};

            node at (b){b};

            node at (x){x};

            node at (z){z};

            draw<2->[ultra thick, green, -latex] (a) -- (b);

            draw[blue!40!black, thick, fill=blue!40!white, opacity=.5] (x) circle (.2cm) node (c){};

            draw<3->[ultra thick, red, -latex] (c.center) -- (z);

        end{tikzpicture}

    end{center}

end{frame}



end{document}

You can also just name the nodes, like

node at (1,1)(a){a};

But then you need to use draw (a.center) -- (b.center) if you want the same behavior (normally the arrows will stop at the node boundary, otherwise).