Writing RMSE fomula in Matlab

How to code this RMSE in matlab. Im stuck to do sum of series because it have double argrument.

N = length of signal

[Torsten]

Are you sure you set the brackets correcty in the formula ?

[Amir Hamzah]

N = length(alldata);
    TrainingAccuracy = sqrt((symsum(((Y - T).^2),N,1,N))/N);

is it correct?

Answer 1

[DGM]

Assuming that the inputs are of comparable scale and of floating-point class:

rmse = sqrt(mean((A(:)-B(:)).^2))