retistruct (version 0.5.9)

f: Piecewise smooth function used in area penalty

Description

Piecewise, smooth function that increases linearly with negative arguments. $$f(x) = \left{ \begin{array}{ll} -(x - x_0/2) & x < 0 \ \frac{1}{2x_0}(x - x_0)^2 & 0 < x

Usage

f(x, x0)

Arguments

x

Main argument

x0

The cutoff parameter. Above this value the function is zero.

Value

• The value of the function.