Why do I get "Array indices must be positive integers or logical values" error when using?

Array indices must be positive integers or logical values.

clc;

clear;

y(1)=0;

y(2)=1;

k=3.50

y=2 - 0.4 +1.2*y(k-1) -0.72*y(k-2);

stem(k,y,'linewidth',2);

grid;

xlabel('K');

k=0.49;

Answer 1

[James Tursa]

k is 3.5

So y(k-1) is y(2.5) and y(k-2) is y(1.5). The indexes are not positive integers, hence the error.

Maybe you meant

k = 3;

y(k) = 2 - 0.4 +1.2*y(k-1) -0.72*y(k-2);

[Josué Cartujano Barrera]

Thank you very much, you are right, i meant 3:50!!