How to change axis linewidth and fontsize in Octave

Question

I am trying to resize some plots in Octave. I've been able to change the line thickness and axis labels. However, I cannot find a way to make the axes themselves thicker, or the numbers larger.

What I've found online uses set(), like

plot(x, y, "linewidth",5);
h=get(gcf, "currentaxes");
set(h, "fontsize", 12, "linewidth", 2);

or

set(gca, 'linewidth', 4);

But, I am continuing to see the errors

invalid property 'linewidth'
invalid property 'fontsize'

even though they are listed as properties in the Octave documentation

What am I doing wrong?

Or, what else can I try?

Solution

With octave 3.8.2 it is working fine.

x=1:10;
plot(x, x, "linewidth", 5)
set(gca, "linewidth", 4, "fontsize", 12)

yields

as it should