step function
Heaviside step function.
x
is the input value.
Specification: http://mathworld.wolfram.com/HeavisideStepFunction.html
If x > 0, returns 1.
If x == 0, returns 1/2.
If x < 0, returns 0.
Example:
print(step(0.5)); // Output: 1
Implementation
double step(double x) {
if (x > 0) return 1;
if (x < 0) return 0;
return 0.5;
}