The font name is 'Arial' not 'Ariel'...
You can change the font by
set(gca, 'FontName', 'Arial')
On one of the Matlab help page says: Note that MATLAB does not display the x-, y-, and z-axis labels in a new font until you manually reset them (by setting the XLabel, YLabel, and ZLabel properties or by using the xlabel, ylabel, or zlabel command). Tick mark labels change immediately.
So for the labels you need to put the x/ylabel commands after you change the font to arial.
Best, Razvan
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