# naginterfaces.library.sparse.direct_​real_​gen_​solve¶

naginterfaces.library.sparse.direct_real_gen_solve(trans, iprm, il, lval, iu, uval, b)[source]

direct_real_gen_solve solves a real sparse system of linear equations with multiple right-hand sides given an factorization of the sparse matrix computed by direct_real_gen_lu().

For full information please refer to the NAG Library document for f11mf

https://www.nag.com/numeric/nl/nagdoc_28.7/flhtml/f11/f11mff.html

Parameters
transstr, length 1

Specifies whether or is solved.

is solved.

is solved.

iprmint, array-like, shape

The column permutation which defines , the row permutation which defines , plus associated data structures as computed by direct_real_gen_lu().

ilint, array-like, shape

Records the sparsity pattern of matrix as computed by direct_real_gen_lu().

lvalfloat, array-like, shape

Records the nonzero values of matrix and some nonzero values of matrix as computed by direct_real_gen_lu().

iuint, array-like, shape

Records the sparsity pattern of matrix as computed by direct_real_gen_lu().

uvalfloat, array-like, shape

Records some nonzero values of matrix as computed by direct_real_gen_lu().

bfloat, array-like, shape

The right-hand side matrix .

Returns
bfloat, ndarray, shape

The solution matrix .

Raises
NagValueError
(errno )

On entry, .

Constraint: .

(errno )

On entry, .

Constraint: .

(errno )

On entry, .

Constraint: or .

(errno )

Incorrect row permutations in array .

(errno )

Incorrect column permutations in array .

Notes

direct_real_gen_solve solves a real system of linear equations with multiple right-hand sides or , according to the value of the argument , where the matrix factorization corresponds to an decomposition of a sparse matrix stored in compressed column (Harwell–Boeing) format, as computed by direct_real_gen_lu().

In the above decomposition is a lower triangular sparse matrix with unit diagonal elements and is an upper triangular sparse matrix; and are permutation matrices.