 Patch test (finite elements)

The patch test is a numerical verification method used in the finite element method (FEM) to assess the accuracy and convergence properties of finite element formulations. It is primarily applied to ensure that a finite element method is capable of accurately representing certain types of exact solutions, particularly those that are polynomial in nature. ### Purpose of the Patch Test 1. **Verification of Element Formulation**: The patch test helps verify whether the finite element formulation can reproduce constant and linear solutions within a specified domain.