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LAPACK
3.7.0
LAPACK: Linear Algebra PACKage
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subroutine dgttrs | ( | character | TRANS, |
integer | N, | ||
integer | NRHS, | ||
double precision, dimension( * ) | DL, | ||
double precision, dimension( * ) | D, | ||
double precision, dimension( * ) | DU, | ||
double precision, dimension( * ) | DU2, | ||
integer, dimension( * ) | IPIV, | ||
double precision, dimension( ldb, * ) | B, | ||
integer | LDB, | ||
integer | INFO | ||
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DGTTRS
Download DGTTRS + dependencies [TGZ] [ZIP] [TXT]
DGTTRS solves one of the systems of equations A*X = B or A**T*X = B, with a tridiagonal matrix A using the LU factorization computed by DGTTRF.
[in] | TRANS | TRANS is CHARACTER*1 Specifies the form of the system of equations. = 'N': A * X = B (No transpose) = 'T': A**T* X = B (Transpose) = 'C': A**T* X = B (Conjugate transpose = Transpose) |
[in] | N | N is INTEGER The order of the matrix A. |
[in] | NRHS | NRHS is INTEGER The number of right hand sides, i.e., the number of columns of the matrix B. NRHS >= 0. |
[in] | DL | DL is DOUBLE PRECISION array, dimension (N-1) The (n-1) multipliers that define the matrix L from the LU factorization of A. |
[in] | D | D is DOUBLE PRECISION array, dimension (N) The n diagonal elements of the upper triangular matrix U from the LU factorization of A. |
[in] | DU | DU is DOUBLE PRECISION array, dimension (N-1) The (n-1) elements of the first super-diagonal of U. |
[in] | DU2 | DU2 is DOUBLE PRECISION array, dimension (N-2) The (n-2) elements of the second super-diagonal of U. |
[in] | IPIV | IPIV is INTEGER array, dimension (N) The pivot indices; for 1 <= i <= n, row i of the matrix was interchanged with row IPIV(i). IPIV(i) will always be either i or i+1; IPIV(i) = i indicates a row interchange was not required. |
[in,out] | B | B is DOUBLE PRECISION array, dimension (LDB,NRHS) On entry, the matrix of right hand side vectors B. On exit, B is overwritten by the solution vectors X. |
[in] | LDB | LDB is INTEGER The leading dimension of the array B. LDB >= max(1,N). |
[out] | INFO | INFO is INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value |
Definition at line 140 of file dgttrs.f.