change font size on gnuplot
<p>I know there have been several posts on how to change the font size on gnuplot. However, in my code, even though I take the solution in previous posts, the output figures have no change. My code is :</p>

<pre><code>set terminal png size 1280, 480;
set xrange [0:100]
set yrange [0:1]
set xlabel 'n'
set ylabel 'x_n'
set tics font ",1"
set output './time_series/r'.i.'.'.j.''.k.''.l.'.png';
set title 'r = '.i.'.'.j.''.k.''.l;

do for [i=0:3]{
    do for [j=0:9]{
    do for [k=0:9]{
    do for [l=0:9]{
    plot './time_series/r'.i.'.'.j.''.k.''.l.'.txt' every ::0::100 with linespoints ls 1 ps 1 pt 7 notitle
    }
    }
    }
}
</code></pre>

<p>The command has no effect with any number I put into, i.e. </p>

<pre><code>set tics font ",a number"
</code></pre>

<p>Any number produces the same font. Is there anything I missed?</p>

<p>Thank you everyone.</p>

<p>Update :
Thanks Raphael. Here are two png produced. The first is with [set tics font ",1"]. The second, [set tics font ",10"].
<a href="https://i.stack.imgur.com/W80jk.png" rel="noreferrer"><img src="https://i.stack.imgur.com/W80jk.png" alt="enter image description here"></a>
<a href="https://i.stack.imgur.com/fom3x.png" rel="noreferrer"><img src="https://i.stack.imgur.com/fom3x.png" alt="enter image description here"></a></p>