# Graph theory: Make vertex labels in plots bigger

Is it possible to make the labels for the vertices of graphs bigger? I can make the vertices themselves bigger but that doesn't seem to change the size of the labels.

Thank you.

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Imho it's easier to write a few lines of code to plot graphs using plotting primitives, something like code below. S denotes my graph (a simple dictionary, for each key u, S[u] is the list of neighbours), xy is a dictionary which indicates positions of vertices, defined elsewhere as are ms (vertex size) and fs (font size).

    G = Graphics()
p = [xy[u] for u in S]
c = [my_color(u) for u in S]
G += scatter_plot (p, markersize = ms, facecolor = c, **kwds)
for u in S:
for v in S[u]:
G += line ([xy[u], xy[v]])
G += sum (text (my_str(u), xy[u], fontsize = fs, zorder = 10) for u in S)


It's that simple, and anything (position, size, color of vertices, font size, text to display for each vertex) is under control.

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It may be easier if you know how to do it. :) I could learn a thing or two from studying your code. For me, it's easier for ppurka to make a tracticket and create a new feature :) The problem is it'll take 1 month before it's on our Sage server, but I don't need it that badly. All kidding aside, though this is more of an advanced technique for someone like me, this is a very good thing to know. So, thanks for your answer.

I have opened #13827 for this.

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One way is to use figsize to indirectly change the relative size of the labels.

P = graphs.PetersenGraph()
P.show(figsize=[1,1],vertex_size=0,layout='spring')


The output of this is: more