function val = regSquare(x,delta)

The function approximates , such that the derivative is non-zero in x=0.

Function	Approximation	Range
y = regSquare(x)		abs(x) >> delta
y = regSquare(x)		abs(x) << delta

With the default value of delta=0.01, the difference between x² and regSquare(x) can be seen in the figure presented below.