# errors on function vs time plot

4 views (last 30 days)
Laila on 19 Jan 2023
Commented: Star Strider on 19 Jan 2023
Hi, I am trying to make a function vs time plot of v = 12e^(-8t) vs time using t =linspace(-1,1,100) (i also wasnt sure what parameters to use for the linspace funcation) where v = 0 when t is less then 00. But when i try to run the code it says there is an error in my v(t) equation line. I have't used MATHLAB a lot so im not sure if its a sytax issue or something else. This is my code. Thanks for any help!
system v(t)
t = linspace(-1,1,100);
v(t) = 12.*e^-8.*t;
if t < 0
v(t) = 0;
plot(v(t), t);
end
Laila on 19 Jan 2023
I have also tried using exp(1) instead of e but still no luck.

Torsten on 19 Jan 2023
Edited: Torsten on 19 Jan 2023
t = linspace(-1,1,100);
v = 12*exp(-8*t).*(t>=0);
plot(t,v) Laila on 19 Jan 2023
thank you!

Star Strider on 19 Jan 2023
The exponential function in MATLAB (and every other programming language I have encountered) is exp.
Try something like this —
t = linspace(-1,1,100);
v = @(t) 12.*exp(-8.*t);
vt = v(t);
vt(t < 0) = 0;
figure
plot(t, vt); .
##### 2 CommentsShowHide 1 older comment
Star Strider on 19 Jan 2023
My pleasure!