petsc-3.14.6 2021-03-30
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Produce the element Jacobian for a chunk of elements by quadrature integration


#include "petscfe.h" 
PetscErrorCode PetscFEIntegrateJacobian(PetscDS prob, PetscFEJacobianType jtype, PetscInt fieldI, PetscInt fieldJ, PetscInt Ne, PetscFEGeom *cgeom,
                                        const PetscScalar coefficients[], const PetscScalar coefficients_t[], PetscDS probAux, const PetscScalar coefficientsAux[], PetscReal t, PetscReal u_tshift, PetscScalar elemMat[])
Not collective

Input Parameters

prob - The PetscDS specifying the discretizations and continuum functions
jtype - The type of matrix pointwise functions that should be used
fieldI - The test field being integrated
fieldJ - The basis field being integrated
Ne - The number of elements in the chunk
cgeom - The cell geometry for each cell in the chunk
coefficients - The array of FEM basis coefficients for the elements for the Jacobian evaluation point
coefficients_t - The array of FEM basis time derivative coefficients for the elements
probAux - The PetscDS specifying the auxiliary discretizations
coefficientsAux - The array of FEM auxiliary basis coefficients for the elements
t - The time
u_tShift - A multiplier for the dF/du_t term (as opposed to the dF/du term)

Output Parameter

elemMat - the element matrices for the Jacobian from each element


Loop over batch of elements (e):
  Loop over element matrix entries (f,fc,g,gc --> i,j):
    Loop over quadrature points (q):
      Make u_q and gradU_q (loops over fields,Nb,Ncomp)
        elemMat[i,j] += \psi^{fc}_f(q) g0_{fc,gc}(u, \nabla u) \phi^{gc}_g(q)
                     + \psi^{fc}_f(q) \cdot g1_{fc,gc,dg}(u, \nabla u) \nabla\phi^{gc}_g(q)
                     + \nabla\psi^{fc}_f(q) \cdot g2_{fc,gc,df}(u, \nabla u) \phi^{gc}_g(q)
                     + \nabla\psi^{fc}_f(q) \cdot g3_{fc,gc,df,dg}(u, \nabla u) \nabla\phi^{gc}_g(q)

See Also







src/dm/dt/fe/impls/basic/febasic.c:713:PetscErrorCode PetscFEIntegrateJacobian_Basic(PetscDS ds, PetscFEJacobianType jtype, PetscInt fieldI, PetscInt fieldJ, PetscInt Ne, PetscFEGeom *cgeom,
Index of all FE routines
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Index of all manual pages