Congratulation! You have your algorithm almost working, but you are using vector when you should be using scalars (As you have your code implemented. Try with this:
t=0:100;
spike_time = 20;
spike_peak =0.2;
spike_decay =5;
g = zeros(length(t),1);
for k = 1:length(t)
if t(k) <= spike_time
g(k) = 0;
else
g(k) = spike_peak*exp(-(t(k)-spike_time)/spike_decay);
end
end
plot(t,g)
As I said before, good job
