# How to add the signals according to time?

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Reji G on 21 Apr 2022
Commented: Mathieu NOE on 21 Apr 2022
Hello,
1. I want to add the 3 decaying exponential sinusoids according to the timwe in one graph. I used hold on & hold off. But that is not the correct way.
2. I want the pattern(1 complete cycle(combination of 3 exp signals)) to be repetitive.
clc;
close all;
clear all;
t=0:0.001:0.3;
a=-7.4*exp(-t/0.01).*sin(2*pi*(10)*t);
t1=0.3:0.001:0.4;
b=10^7*exp(-t1/0.02).*sin(2*pi*(10)*t1);
b1=flip(b);
t2=0.4:0.001:0.75;
c=-8.5^10*exp(-t2/0.02).*sin(2*pi*(10)*t2);
c1=flip(c);
t3=0:0.001:0.1;
d=sin(2*pi*50*t3);
figure(1)
plot(t/38,a,'b');
hold on
plot(t1/38,b1,'b');
hold on
plot(t2/38,c1,'b');
hold on
plot(t3,d);
hold off
##### 2 CommentsShowHide 1 older comment
Reji G on 21 Apr 2022
In one x axis, from 0 to 0.3 seconds, signal 'a' should be plotted. In the same axis, from 0.3 to 0.4 signal b1 should be plotted. From 0.4 to 0.75 signal c1 should be plotted.
After 0.75 second the entire plot should repeat.

Mathieu NOE on 21 Apr 2022
Edited: Mathieu NOE on 21 Apr 2022
hello
clc;
close all;
clear all;
% In one x axis, from 0 to 0.3 seconds, signal 'a' should be plotted.
% In the same axis, from 0.3 to 0.4 signal b1 should be plotted.
% From 0.4 to 0.75 signal c1 should be plotted.
% After 0.75 second the entire plot should repeat.
dt = 0.001;
t1=0:dt:0.3-dt; % remove one sample at the end ( dt) to avoid duplicate with next segment first point
a=-7.4*exp(-t1/0.01).*sin(2*pi*(10)*t1);
t2=0.3:dt:0.4-dt; % remove one sample at the end ( dt) to avoid duplicate with next segment first point
b=10^7*exp(-t2/0.02).*sin(2*pi*(10)*t2);
b1=flip(b);
t3=0.4:dt:0.75;
c= + 8.5^10*exp(-t3/0.02).*sin(2*pi*(10)*t3); % changed sign from - to + here because it looked weird to me
c1=flip(c);
t=[t1 t2 t3];
y = [a b1 c1];
figure(1)
plot(t/38,y,'b');
% create repetitions of the signal
rep = 10; % repetitions
y_rep = repmat(y,[1 rep]);
t_rep = (0:numel(y_rep)-1)*dt;
figure(2)
plot(t_rep/38,y_rep,'b');
##### 2 CommentsShowHide 1 older comment
Mathieu NOE on 21 Apr 2022
as always , my pleasure !

R2021b

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