Trouble plotting a piecewise defined function in MATLAB

Question

I'm trying to plot a simple piecewise defined function in MATLAB R2016a. While t is negative, this code should plot v = 0 and when t is positive (or zero), the code should plot v = 10*exp(-5000*t) . Here's the code:

t = -0.0014:1e-5:0.0014;
v = zeros(1, length(t));
for i = 1:length(t)
    if t(i) < 0
        v(i) = 0;
    elseif t(i) >= 0
        v(i) = 10*exp(-5000*t);
    end
end
plot(t, v)

This m-file looks right to me, but I keep getting the error

In an assignment  A(:) = B, the number of elements in A and B must be the same.

Error in PiecewiseFunction (line 10)
        v(i) = 10*exp(-5000*t);

I suspect it's something simple, but I just don't see it!

Answer 1

问题上的注释可以回答问题，但是如果将其向量化，则可以使此代码更简单：

v = 10*exp(-5000*t).*(t >= 0);