FEATool
v1.8 Finite Element Analysis Toolbox |

assemblea.m File Reference

ASSEMBLEA Finite element assembly of bilinear forms.

[ VROWINDS, VROWCOLS, VAVALS, N_ROWS, N_COLS ] = ASSEMBLEA( FORM, C_SFUN, C_COEF, ICUB, P, C, A, SIND, N_CMAX, N_OFF, PROB, I_HRZ ) Assembles a matrix representation of a finite element bilinear form.

Each column in FORM specify one bilinear additive term to compute. The first row corresponds to the trial function space, and second test space. The FORM entries denote either function values or derivatives to evaluate.

C_SFUN indicates which shape functions to use for the trial and test spaces.

C_COEF specifies the coefficients to evaluate for each term (column) in FORM.

The computed matrix entries are returned in VAVALS where VROWINDS and VROWCOLS are corresponding row and column pointers. N_ROWS and N_COLS give the number of rows in the matrix. A sparse representation of the matrix can subsequently be constructed by calling SPARSE

A = sparse( vRowInds, vColInds, vAvals, n_rows, n_cols );

on the output of ASSEMLBLEA.

Input Value/[Size] Description ----------------------------------------------------------------------------------- form [2,n_forms] Forms to compute, first row indicates trial function space (second test function space) 1 = function value 2/3/4 = x/y/z -derivatives c_sfun strings {2} Shape functions used for the trial and test function spaces c_coef {n_forms} Coefficients for each bilinear form i_cub scalar Numerical integration rule p [n_sdim,n_p] Array with grid point coordinates c [n_vert,n_cells] Array with cell connectivities a [n_vert,n_cells] Array with cell adjacency information sind [n_cells] (optional) Subdomain indices n_cmax scalar (optional) Max number of cells to assemble for at once (to limit memory consumption) n_off [2] (optional) Row/column pointer offset prob struct (optional) FEATool problem struct, used for dofmapping and evaluating coefficients i_hrz scalar {0} Apply HRZ diagonal (mass) lumping . Output Value/[Size] Description ----------------------------------------------------------------------------------- vRowInds [n_A] Row pointers to matrix entries vColInds [n_A] Column pointers to matrix entries vAvals [n_A] Values of the assembled matrix entries n_rows scalar Number of rows in matrix n_cols scalar Number of columns in matrix

- See also
- assembleprob, asmrowcolptr, mapdofbdr