Error while setting LineWidth of Axes

Hi I want to achieve custom plots were the box/frame linewidth would be thicker than 0.5pt My code is the next:

plot(x,y,'LineWidth',1.5);
pbaspect([4 1.5 1])
set(gca, 'Layer','top')
box on

To here if I plot every thing is OK,

now if I ad the next line that according to MatLab Help increases the width of axes

axes('WidthLine',2)

I get this

And if I ad this

box('LineWidth',2)

I get just the following error

Error using box (line 26)
First argument must be an axes handle.

Error in graficador (line 12)
box('LineWidth',2)

but according to the manual 'LineWidth' is an axes handle. So What is wrong with my attempt ?

Answer 1

[Stalin Samuel]

set(gca, 'LineWidth', 2)