How to add some fluctuation in the flat line?

Question

Nisar Ahmed 2021-11-4

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1579176-how-to-add-some-fluctuation-in-the-flat-line

评论： Jon 2021-11-8

Hi,

In the upper part of attached/copied figure, the encircled area, the graph has values equal to one (straight/flate line). Suppose I want add some fluctuation in the flat line such that numerical values remain in between 0.96 -0.99.

Is there any way I can do in Matlab? Please guide me in this regard.

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Jon 2021-11-4

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1579176-how-to-add-some-fluctuation-in-the-flat-line#answer_823980

编辑：Jon 2021-11-4

在 MATLAB Online 中打开

I think you can adapt the approach that I illustrate here:

% generate original function with flat zone
t = linspace(1970,1880);
x = zeros(size(t));
% use logical indexing to work on specific portions of curve
x(t<1918) = 1;
x(t>1918) = 0.5+0.1*randn(size(x(t>1918)));
% plot original curve
figure,plot(x,t)
% make the early years noisy too
sigma = 0.015;
xbar = (0.96+0.99)/2;
x(t<1918) = xbar + sigma*randn(size(x(t<1918)));
figure,plot(x,t)

My y axis (years?) is increasing rather than decreasing like yours. This is the normal way to make an x-y plot. I'm not sure if this is important to you. I mostly just wanted to illustrate how you add the noise to a selected portion of your graph.