UnitStep

The unit step function: 0 for x < 0 and 1 for x >= 0.

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UnitStep(x)0 if x < 0, 1 if x >= 0.

UnitStep(x1, x2, …)the product of the unit steps -- 0 as soon as any argument is negative.

Typed signatures

Type	Package	Applies
`(list<number> \| number, number*) -> list<number> \| number`	`analytic`	always

Domain: Elementary functions

Details

1 at exactly 0, unlike Heaviside's $\tfrac12$ there.
Several arguments: 0 the moment any one of them is negative, 1 otherwise -- the multivariate step used for a region like $x \ge 0 \wedge y \ge 0$ .
A single list argument threads element-wise; several scalar arguments combine as above -- the two call forms are not the same shape.