How do I change the values ​​of the axes?

Hi I have this plot:

figure; errorbar(y,e,'-o')
legend('Cist -9dB', 'Cist -6dB', 'Cist -3dB', 'Cist 3dB', 'Cist 6dB', 'Cist 9dB');
xlabel('Gain');
ylabel('Grey Levels'); 
title('Dynamic range of 20dB'); 

The x axis start from 0 to 21, because I have 21 one point, how can I make the axis start from -20dB to 20dB (every 2 dB, To correspond to the first point -20dB, to the second -18 and so on: at each point increase of 2 dB up to +20)

Answer 1

[Star Strider]

Try something like this —

x = linspace(0, 21, 25);
y = rand(size(x));

figure
plot(x, y)
xt = get(gca, 'XTick');
xtv = linspace(min(xt), max(xt), 21);
set(gca, 'XTick',xtv, 'XTickLabel',compose('%3d dB',-20:2:20))

Make appropriate changes to get the result you want.

.