I commented in other post, but this is a possible answer:
time = linspace(-40,40,2000); %change limits
signal = 80*sind(2*180*time); %sine wave in degree
i = -40; j = 1;
comp = 25:25:2000;
vectorx = zeros(1,length(time));
% Simulated Error
for n = 1:length(time)
vectorx(n) = i;
if(n == comp(j))
i = i+1;
j = j+1;
end
end
errorSimulated = rand(1,length(vectorx));
%End simulated error
yyaxis left; %name axis Y left
plot(time,signal); hold on; %plot sine wave0
ylabel('Sinusoidal signal')
ylim([-90 90]) %Y limits
yyaxis right; %name axis Y right
scatter(vectorx,errorSimulated,'filled','r') %scatter of error
ylabel('Simulated error')
xlim([-40 40]) %X limits
