Module validate 

Geometry validation with a scale-aware tolerance: every threshold is relative to the element’s characteristic length squared (its longest node-to-node distance squared), never an absolute number, so a unit element and a 1e6-scaled copy are judged identically.

Functions

validate_quad

A quad needs distinct nodes and a positive det J at all four reference corners.

validate_triangle

A triangle needs distinct nodes, area above tolerance, and counter-clockwise order.