Editing Analog signal processing (section)

===Step===
A unit step function, also called the [[Heaviside step function]], is a signal that has a magnitude of zero before zero and a magnitude of one after zero.  The symbol for a unit step is u(t).  If a step is used as the input to a system, the output is called the step response.  The step response shows how a system responds to a sudden input, similar to turning on a switch.  The period before the output stabilizes is called the transient part of a signal.  The step response can be multiplied with other signals to show how the system responds when an input is suddenly turned on.

The unit step function is related to the Dirac delta function by;

:<math>\mathrm{u}(t) = \int_{-\infty}^{t} \delta (s)ds</math>