Operations on sequence Discrete-Time Signals and Systems--Digital Signal Processing 6.Sample summation 4 ∑x(n)=x(n)++x(n) n=n ss sum(x(n1:n2); 7.Sample production n2 Πx(n)=x(n)×…×x(n2) n=n sp prod(x(n1:n2)); 上游充通大Operations on sequence Discrete-Time Signals and Systems —— Digital Signal Processing 6. Sample summation ss = sum(x(n1:n2); 7. Sample production sp = prod(x(n1:n2));     2 1 ( ) ( ) ( ) 1 2 n n n x n x n  x n ( ) ( ) ( ) 1 2 2 1 x n x n x n n n n      