# MATLAB: How to plot a restoration-based envelope in matlab

curve fittingenvelopeMATLABplotplotting

Hello greetings to everyone
I have a damping sine curve (code and data attached) as the following and I intend to do the following action on it, and make an envelope like the dashed curve: How can I plot these max and min and plot a fit envelope like the dashed curve as above in MATLAB (The crosses are the midpoint of each line on which they are located)
Thanks in advance for your time given on this question and stay healthy

``T = t(end)/10;        % period - there seem to be 10 periods in the rangeit = t(t<=T);         % times up to one perioddt = numel(it)/2;     % number of time points in a half periodn = 20;               % total number of half periodsmn = zeros(n,1);      % store for minimamn(end) = min(R1);    % last minimummx = mn;              % store for maximamx(1) = 1;            % first maximum% Find sizes of minima and maximafor i = 2:n    tspan = (i-1)*dt:i*dt;    mn(i-1) = min(R1(tspan));    mx(i) = max(R1(tspan)); end% Assume "restoration" times occur at half period intervals% starting at T/4 (an approximation)Ravpts = (mn+mx)/2;tavpts = (T/4:T/2:n*T/2);% Interpolate for "restoration" plottav = T/4:t(end);Rav = interp1(tavpts,Ravpts,tav,'pchip');% Plotsplot(t,R1,tavpts,Ravpts,'o',tav,Rav,'k--'), gridxlabel('t'),ylabel('damped sinusoid')legend('data','restoration points','interpolated restoration')`` 