A step function is a function on the reals 
if it can be written as a finite linear combination of semi-open
intervals 
.
Therefore, a step function 
can be written as
 |
where 
,
if 
and 0 otherwise, for 
, ..., 
.
Step Function
See also
Heaviside Step FunctionExplore with Wolfram|Alpha
Cite this as:
Weisstein, Eric W. "Step Function." From MathWorld--A Wolfram Resource. https://mathworld.wolfram.com/StepFunction.html