Solving LTID system recursively

I want to solve this system recursively

y[n]−0.7y[n−1]+0.12y[n−2]=2x[n]−x[n−1]

with

x[n]=(2)−nu[n]; y[−1]=3 and y[−2]=2

what i have tried is this but i keep getting Array indices must be positive integers or logical values.

any suuggestions?

 n=-2:15;
%  y=[2;3;zeros(length(n)-2,1)]; %I.C
 y(-2)=2;
 y(-1)=3;
 x=inline('2.^(-n).*(n>=0)'); % input system
 for k = 1: length(n)-2
     y(k) = 0.7*y(k-1)-0.12*y(k-2)+2*x(k)-x(k-1);
 end
 
clf;
stem(n,y);
disp('n y'); disp([num2str([n,y])]);

Answer 1

[Alan Stevens]

Matlab indexing begins at 1, so you can't have y(-2), y(-1), y(0) etc. Shift your indexing.

y(1) = 2;
y(2) = 3;
for k = 3: length(n)
    y(k) = ...etc