Legendre Transformation of a one variable function

Given a function F and a vector x, returns two vectors of numbers xx=F'(x) and yy=F(x)-x*xx

Description

[xx,yy]=legendretrans01(F,x,h,varargin)
Given a function F and a vector x, the corresponding points of the legendre
transformation are numerically approximated and stored in the vectors xx and yy, where
xx=F'(x) and yy=F(x)-xx*x
If F is not defined for vectors, a loop is used to evaluate it at each point on x

F'(x) is approximated by centered finite differences

• MATLAB release: MATLAB 5.3 (R11)

[Mimi]

Could you be possibly missing a negative sign? I'm getting -yy as my output. Either that, or my output yy is supposed to be the negative Legendre transform.