In a similar way, we can compute the
signal energy

(sum of squared moduli) using any of the following constructs:
Ex = x(:)' * x(:)
Ex = sum(conj(x(:)) .* x(:))
Ex = sum(abs(x(:)).^2)
The average power (energy per sample) is similarly
Px = Ex/N.
The
norm is similarly
xL2 = sqrt(Ex) (same result as
xL2 = norm(x)). The

norm is given by
xL1 =
sum(abs(x)) or by
xL1 = norm(x,1). The infinity-norm
(
Chebyshev norm) is computed as
xLInf = max(abs(x)) or
xLInf = norm(x,Inf). In general,

norm is computed by
norm(x,p), with
p=2 being the default case.

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