FEATool Multiphysics  v1.16.4 Finite Element Analysis Toolbox
sfnonconp1.m File Reference

## Description

SFNONCONP1 Shape function driver (first order P1 Lagrange polynomials).

[ VBASE, NLDOF, XLDOF, SFUN ] = SFNONCONP1( I_EVAL, N_SDIM, N_VERT, I_DOF, XI, AINVJAC, VBASE ) Evaluates nonconforming linear (P-1/P1) shape functions with degrees of freedom defined on the cell edges/faces for simplices and interior for quadrilaterals/hexahedrals.

Input       Value/[Size]           Description
-----------------------------------------------------------------------------------
i_eval      scalar:  1             Evaluate function values
>1             Evaluate values of derivatives
n_sdim      scalar: 2-3            Number of space dimensions
n_vert      scalar: 2-8            Number of vertices per cell
i_dof       scalar: 1-n_ldof       Local basis function to evaluate
xi          [n_sdim(+1)]           Local coordinates of evaluation point
aInvJac     [n,n_sdim(+1)*n_sdim]  Inverse of transformation Jacobian
vBase       [n]                    Preallocated output vector
.
Output      Value/[Size]           Description
-----------------------------------------------------------------------------------
vBase       [n]                    Evaluated function values
nLDof       [4]                    Number of local degrees of freedom on
vertices, edges, faces, and cell interiors
xLDof       [n_sdim,n_ldof]        Local coordinates of local dofs
sfun        string                 Function name of called shape function

sf_simp_P1nc, sf_disc1

# Code listing

 if ( n_sdim==1 )

error('sfnonconp1: 1D nonconforming shape functions not supported.')

elseif ( n_vert==n_sdim+1 )   % Simplex cells (2D triangle or 3D tetrahedron).

[vBase,nLDof,xLDof,sfun] = sf_simp_P1nc(i_eval,n_sdim,n_vert,varargin{:});

else

[vBase,nLDof,xLDof,sfun] = sf_disc1(i_eval,n_sdim,n_vert,varargin{:});

end