How to obtain the sum of series of a discrete-time signal?

I want to obtain the value for the below function in Matlab.

fs = 5000; %sampling frequency

N=250; %number of samples for 50ms time portion

ts=1/fs; %time interval between samples

t = linspace(0,0.05,N);

x = sin(2*pi*100*t)+0.7*cos(2*pi*500*t);

The x[n] is given above. y[n] is the denoised case of the white gaussian noise added x[n] signal.

I'have tried

F1=symsum((x(n)-y(n))^2/x(n)^2,n,0,N-1);

but it didn't work.

How can I define the x in terms of n?

Answer 1

[Hiro Yoshino]

Do you intend to use Symbolic Math Toolbox?

In that case, you need to define your variables as follows:

syms x y n

before beginning to code that way.