9th April 2013
HSL_MA42_ELEMENT solves one or more sets of sparse linear unsymmetric unassembled ﬁnite-element equations, , or , or , by the frontal method. The system may be real or complex ( denotes the conjugate transpose of ). There are options for automatically ordering the elements, for supplying the elements using a reverse communication interface, for holding the matrix factors in direct-access ﬁles, and for preserving a partial factorization.
The coeﬃcient matrix must have a symmetric structure and must be in elemental form
where is nonzero only in those rows and columns that correspond to variables in the -th ﬁnite element. The elements must be square elements, with the row indices equal to the column indices. For each , the user must supply a list specifying which rows/columns of are associated with and an array containing the nonzero entries. The right-hand sides may be supplied in elemental form (that is, ) or in assembled form.
Precision: At least 8-byte arithmetic is recommended.