#include "petscdt.h"
#include "petscdmmoab.h"
PetscErrorCode Compute_Lagrange_Basis_2D_Internal(const PetscInt nverts, const PetscReal *coords, const PetscInt npts, const PetscReal *quad, PetscReal *phypts,
PetscReal *jxw, PetscReal *phi, PetscReal *dphidx, PetscReal *dphidy,
PetscReal *jacobian, PetscReal *ijacobian, PetscReal *volume)
The routine is given the coordinates of the vertices of a quadrangle or triangle.
The routine evaluates the basis functions associated with each quadrature point provided, and their derivatives with respect to X and Y.
Example Physical Element (QUAD4)
4------3 s
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| | |
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1------2 0-------r
| PetscInt nverts | - the number of element vertices | |
| PetscReal coords[3*nverts] | - the physical coordinates of the vertices (in canonical numbering) | |
| PetscInt npts | - the number of evaluation points (quadrature points) | |
| PetscReal quad[3*npts] | - the evaluation points (quadrature points) in the reference space |
| PetscReal phypts[3*npts] | - the evaluation points (quadrature points) transformed to the physical space | |
| PetscReal jxw[npts] | - the jacobian determinant * quadrature weight necessary for assembling discrete contributions | |
| PetscReal phi[npts] | - the bases evaluated at the specified quadrature points | |
| PetscReal dphidx[npts] | - the derivative of the bases wrt X-direction evaluated at the specified quadrature points | |
| PetscReal dphidy[npts] | - the derivative of the bases wrt Y-direction evaluated at the specified quadrature points |