I keep getting the error "Array indices must be positive integers or logical values?"

I have been editing a code I found that models a 2 cart system using Euler's Method in an attempt to make it a 3 cart system. However, on line 63 I am recieving an error that states "Array indices must be positive integers or logical values." I am not sure what this means or how to fix it. Any help would be apprecieted. Thanks!

Answer 1

[the cyclist]

In expressions like this one

k2(x2(n,:)-x1(n,:))

MATLAB is trying to index into the variable k2. You need to put in the multiplication sign explicitly:

k2.*(x2(n,:)-x1(n,:))

[William Van Beek]

Of course, just fixed it and it runs fine. Thanks!