aligo

x=[1:1006];
w=1.2;
x=sin(w.*x);
q(1)=0;
q(2)=0;
for i=3:1005,
    q(i)=1.5*q(i-1)-0.7*q(i-2)+x(i-1)+0.5*x(i-2)+randn(1,1);
end
for i=1:1000,
    q(i)=q(i+2);

aligo

macro_rules! iflet {
    ([$p:pat = $e:expr] $($rest:tt)*) => {
        if let $p = $e {
            iflet!($($rest)*);
        }
    };
    ($b:block) => {
        $b
    };
}