Monge representation
= Monge representation
The Monge representation describes a nearly flat curve or surface as a single-valued height over a reference line or plane. For a planar curve $(x,h(x))$ with small slope, arclength is $ds=dx+O(h_x^2)$ and signed curvature is $\kappa=h_{xx}+O(h_x^2h_{xx})$.