naginterfaces.library.lapacklin.dgbtrs¶
- naginterfaces.library.lapacklin.dgbtrs(trans, kl, ku, ab, ipiv, b)[source]¶
dgbtrs
solves a real band system of linear equations with multiple right-hand sides,where has been factorized by
dgbtrf()
.For full information please refer to the NAG Library document for f07be
https://support.nag.com/numeric/nl/nagdoc_30.2/flhtml/f07/f07bef.html
- Parameters
- transstr, length 1
Indicates the form of the equations.
is solved for .
or
is solved for .
- klint
, the number of subdiagonals within the band of the matrix .
- kuint
, the number of superdiagonals within the band of the matrix .
- abfloat, array-like, shape
The factorization of , as returned by
dgbtrf()
.- ipivint, array-like, shape
The pivot indices, as returned by
dgbtrf()
.- bfloat, array-like, shape
The right-hand side matrix .
- Returns
- bfloat, ndarray, shape
The solution matrix .
- Raises
- NagValueError
- (errno )
On entry, error in parameter .
Constraint: , or .
- (errno )
On entry, error in parameter .
Constraint: .
- (errno )
On entry, error in parameter .
Constraint: .
- (errno )
On entry, error in parameter .
Constraint: .
- (errno )
On entry, error in parameter .
Constraint: .
- Notes
dgbtrs
is used to solve a real band system of linear equations or , the function must be preceded by a call todgbtrf()
which computes the factorization of as . The solution is computed by forward and backward substitution.If , the solution is computed by solving and then .
If or , the solution is computed by solving and then .
- References
Golub, G H and Van Loan, C F, 1996, Matrix Computations, (3rd Edition), Johns Hopkins University Press, Baltimore