Question

Assume we have a signal, for instance:

x = [1 2 9 16 18 19 18 16 9 7 4 2 1 1 0 0];

and we want to find the location of the signal:

y = [10 8 4 3 1];

which is near to [9 7 4 2 1] and in this example is n = 9.

How can you go about finding n?

Answer 1

As you say, you need to use some sort of cost or likelihood function. Here’s a for loop to start, I’ll let you find the cost function yourself:

x = [1 2 9 16 18 19 18 16 9 7 4 2 1 1 0 0];
y = [10 7 4 3 1];

cor = 9999;
n=0;
for i=1:(length(x)-length(y))

    % Complete this line to check if x matches y at this point
    score = SomeFunctionChecking( x(i : (i+length(y)-1) ),  y ));

    if (score < cor)
        cor = score;
        n = i;
    end
end

display(n);