Index exceeds number of array elements

clear all
clc
close all

y(1) = -100;
y_exact(1) = -100;
t0 = 0;
t_end = 10;
dt = 1/50;
t = t0:dt:t_end;
for i = length(t)-1
    y(i+1) = y(i)+dt*(y0.*y(i)-y0^2*t(i+1));
    y_exact(i+1) = 1+y0.*t(i+1)+(y0-1).*exp(y0.*t(i+1));
end

figure(1)
hold on
plot(t,y,'b-o')
plot(t,y_exact,'r')

When i run this I get an error message in line 12 (y(i+1)-line):

Index exceeds the number of array elements (1).

How can I avoid this?

Answer 1

[James Tursa]

I think you want this

for i = length(t)-1

to be this instead

    for i = 1:length(t)-1

The way you have it currently coded, the index i takes on only one value inside the loop, namely length(t)-1, and those y elements don't exist yet.