# Expression (equation)

6 visualizzazioni (ultimi 30 giorni)
Jan il 8 Dic 2011
Hello, how to define an expression, for example 1-e^(-At) where I can define and change parameters A and t and than figure changes of the curve in a graph.
Thanks
##### 0 CommentiMostra -2 commenti meno recentiNascondi -2 commenti meno recenti

Accedi per commentare.

### Risposta accettata

Paulo Silva il 8 Dic 2011
Simplest version I can think of
t=0:0.1:100; % Time vector
A=0.1; % Value of A that you can change
plot(t,1-exp(-A(n)*t)) % Represent it on a figure
If you place the cursor on the value of A you can try several values using the Editor tools (look on the tools of your editor window - 1.0 + ... press those symbols and the script runs with a new value for A)
Just for fun here's a version using subplots
clf
t=0:0.1:10;
A=[0.01 0.1 0 1];
for n=1:4
subplot(2,2,n)
plot(t,1-exp(-A(n)*t))
title(['A=' num2str(A(n))])
end
##### 9 CommentiMostra 7 commenti meno recentiNascondi 7 commenti meno recenti
Paulo Silva il 8 Dic 2011
It's just basic math, you use the Product block with inputs A and t and connect that block output to the Math Function block
Jan il 8 Dic 2011
thx :)

Accedi per commentare.

### Più risposte (1)

Sean de Wolski il 8 Dic 2011
And to add on to Paulo's example:
t=0:0.1:100; % Time vector
A=0.1;
y = 1-exp(-A*t); % Value of A that you can change
H = figure;
plot(t,y)
shg;
pause(2) %watch the magic in 2 seconds
A = .8;
y = 1-exp(-A*t);
if you want it to automagically update when you change A or y.
##### 3 CommentiMostra 1 commento meno recenteNascondi 1 commento meno recente
Jan il 8 Dic 2011
Thanks a lot Sean :)
Jan il 8 Dic 2011
Is it possible to model it in the Simulink?

Accedi per commentare.

### Categorie

Scopri di più su Exponents and Logarithms in Help Center e File Exchange

### Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by