Editing Analytic signal (section)

===Negative frequency components===
Since <math>s(t) = \operatorname{Re}[s_\mathrm{a}(t)]</math>, restoring the negative frequency components is a simple matter of discarding <math>\operatorname{Im}[s_\mathrm{a}(t)]</math> which may seem counter-intuitive. The complex conjugate <math>s_\mathrm{a}^*(t)</math> comprises ''only'' the negative frequency components. And therefore <math>s(t) = \operatorname{Re}[s_\mathrm{a}^*(t)]</math> restores the suppressed positive frequency components.  Another viewpoint is that the imaginary component in either case is a term that subtracts frequency components from <math>s(t).</math> The <math>\operatorname{Re}</math> operator removes the subtraction, giving the appearance of adding new components.